担当区分：責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

A reduction reaction of 5-hydroxymethylfurfural to 2,5-dimethylfuran (2,5-DMF) has been previously performed in an organic solvent under high-temperature conditions. For the relaxation of such reaction conditions, conventional palladium on carbon (Pd/C) was combined with vesicles composed of phospholipids or surfactants. Pd/C combined with 1,2-dioleoyl-sn-glycero-3-phosphocholine indicated a yield (25%) at 60 °C compared with Pd/C (17%). Vesicles at the liquid crystalline phase were advantageous for the reduction reaction of HMF. The yield of 2,5-DMF catalyzed by Pd/C combined with the vesicles depended on the lipid composition of the vesicles. It was clarified that the yield of 2,5-DMF could be controlled by the hydration property of the vesicles. Compared with conventional 2,5-DMF synthesis in an organic solvent, the use of vesicles made it possible to reduce the burden of using organic solvents in high-temperature conditions, although limitedly.

DOI： 10.3390/compounds2040027

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

Senile plaques that is characterized as an amyloid deposition found in Alzheimer's disease are composed primarily of fibrils of an aggregated peptide, amyloid β (Aβ). The ability to monitor senile plaque formation on a neuronal membrane under physiological conditions provides an attractive model. In this study, the growth behavior of amyloid Aβ fibrils in the presence of liposomes incorporating β-cholesteryl-D-glucose (β-CG) was examined using total internal reflection fluorescence microscopy, transmittance electron microscopy, and other spectroscopic methods. We found that β-CG on the liposome membrane induced the spontaneous formation of spherulitic Aβ fibrillar aggregates. The β-CG cluster formed on liposome membranes appeared to induce the accumulation of Aβ, followed by the growth of the spherulitic Aβ aggregates. In contrast, DMPC and DMPC incorporated cholesterol-induced fibrils that are laterally associated with each other. A comparison study using three types of liposomes implied that the induction of glucose contributed to the agglomeration of Aβ fibrils and liposomes. This agglomeration required the spontaneous formation of spherulitic Aβ fibrillary aggregates. This action can be regarded as a counterbalance to the growth of fibrils and their toxicity, which has great potential in the study of amyloidopathies.

DOI： 10.1016/j.bbapap.2022.140816

Scopus

PubMed

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Here, we present a method for preparing vesicles by combining hydrothermal emulsification with solvent diffusion (SD). The sorbitan monolaurate/polyoxyethylene (20) sorbitan monolaurate (Span 20/Tween 20) system was used as the target lipid because these lipids are cheap and advantageous for the production scale. The water-in-oil (W/O) emulsion stabilized with lipids was formed under hydrothermal conditions (240 °C under 10 MPa), followed by mixing with water that included lipids to obtain a W/O-in-water (W/O/W) emulsion. The SD for the W/O/W emulsion as a subsequent process yielded vesicles. The optimal preparation conditions were 50:50 wt% Span 20/Tween 20 as a mixing ratio (final lipid concentration 12 mM), octanoic acid as an organic solvent, 240 °C for 4 min during the hydrothermal treatment, and 4 °C for 24 h in the SD process. The diameter of the vesicles obtained was at most 100 nm, which was comparable to that of the W/O/W emulsion before SD. This suggested that the W/O/W emulsion acted as a template for vesicle formation. The number density, diameter, and membrane properties of vesicles depend on the mixing ratio of the water/oil/lipid system. Specifically, the number density of vesicles was low relative to that of vesicles prepared by the conventional method.

DOI： 10.1016/j.colsurfb.2021.111836

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

The design of biosensors and artificial organs using biocompatible materials with a low affinity for amyloid β peptide (Aβ) would contribute to the inhibition of fibril growth causing Alzheimer’s disease. We systematically studied the amyloidogenicity of Aβ on various planar mem-branes. The planar membranes were prepared using biocompatible polymers, viz., poly(methyl methacrylate) (PMMA), polysulfone (PSf), poly(L-lactic acid) (PLLA), and polyvinylpyrrolidone (PVP). Phospholipids from biomembranes, viz., 1,2-dioleoyl-phosphatidylcholine (DOPC), 1,2-dipalmitoyl-phosphatidylcholine (DPPC), and polyethylene glycol-graft-phosphatidyl ethanolamine (PEG-PE) were used as controls. Phospholipid-and polymer-based membranes were prepared to determine the kinetics of Aβ fibril formation. Rates of Aβ nucleation on the PSf-and DPPC-based membranes were significantly higher than those on the other membranes. Aβ accumulation, cal-culated by the change in frequency of a quartz crystal microbalance (QCM), followed the order: PSf > PLLA > DOPC > PMMA, PVP, DPPC, and PEG-PE. Nucleation rates exhibited a positive correlation with the corresponding accumulation (except for the DPPC-based membrane) and a negative correlation with the molecular weight of the polymers. Strong hydration along the polymer backbone and polymer–Aβ entanglement might contribute to the accumulation of Aβ and subsequent fibrillation.

DOI： 10.3390/app11104408

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The microcapillary was combined with the liquid-liquid slug flow to build the separation field. The partition behavior of seventeen kinds of substrates was investigated by using six kinds of water/organic biphasic systems under hydrothermal conditions (25 - 190° C at 10 MPa). The scale of hydrophobicity (HF) of water/organic biphasic system was estimated. The HF value for the biphasic system used here was comparable to the conventional aqueous two-phase systems and depended on the (de)solvation of substrates by water and organic solvent. Besides, the vortex field in the slug contributed to the enhanced mass transfer of substrates. Those results are available for the selection of water/organic biphasic system as the reactive separation of target materials.

DOI： 10.15261/SERDJ.28.21

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

The partitioning behavior of horseradish peroxidase (HRP) to phospholipid- and surfactant vesicles has been analyzed. Peripheral binding of the zwitterionic phospholipid vesicle membranes is proposed with insertion into the membrane interior of negatively charged surfactant vesicles, resulting from non-electrostatic interaction. The insertion of HRP is interpreted by considering the interaction between headgroups of phospholipid and between headgroups of surfactant.

DOI： 10.15261/serdj.27.113

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The properties of the liposome membrane as a reaction field were investigated by focusing on the Horner–Wadsworth–Emmons reaction as a case study. Use of the liposomes existing in the gel phase resulted in the enhanced activity of the substrates and furnished the products with same E/Z stereoselectivity as in the liposome-free system. The membrane environment in the gel phase most likely assisted the formation of adducts that induced selective generation of the E-isomer. The possible role of liposomes is to assist the proton removal from the reactant, rather than providing the basic interfacial environment.

DOI： 10.1016/j.jbiosc.2019.01.015

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

Product temperature (Tb) and drying time constitute critical material attributes and process parameters in the lyophilization process and especially during the primary drying stage. In the study, we performed a temperature measurement by the sublimation rate (TMbySR) to monitor the Tb value and determine the end point of primary drying. First, the water vapor transfer resistance coefficient through the main pipe from the chamber to the condenser (Cr) was estimated via the water sublimation test. The use of Cr value made it possible to obtain the time course of Tb from the measurement of pressure at the drying chamber and at the condenser. Second, a Flomoxef sodium bulk solution was lyophilized by using the TMbySR system. The outcome was satisfactory when compared with that obtained via conventional sensors. The same was applicable for the determination of the end point of primary drying. A laboratory-scale application of the TMbySR system was evidenced via the experiment using 220-, 440-, and 660-vial scales of lyophilization. The outcome was not dependent on the loading amount. Thus, the results confirmed that the TMbySR system is a promising tool in laboratory scale.

DOI： 10.1016/j.xphs.2019.02.015

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

The objective of this review is to survey the development of the optimization of lyophilization. The optimization study of the lyophilizer has been roughly developing by the order of (i) trial-and-error approach, (ii) process modeling using mathematical models, (iii) scalability, and (iv) quality-by-design. From the conventional lyophilization studies based on the trial-and-error, the key parameters to optimize the operation of lyophilization were found out, i.e., critical material attributes (CMAs), critical process parameters (CPPs), and critical quality attributes (CQAs). The mathematical models using the key parameters mentioned above have been constructed from the viewpoints of the heat and mass transfer natures. In many cases, it is revealed that the control of the primary drying stage determines the outcome of the lyophilization of products, as compared with the freezing stage and the secondary drying stage. Thus, the understanding of the lyophilization process has proceeded. For the further improvement of the time and economical cost, the design space is a promising method to give the possible operation range for optimizing the lyophilization operation. This method is to search the optimized condition by reducing the number of key parameters of CMAs, CPPs, and CQAs. Alternatively, the transfer of lyophilization recipe among the lab-, pilot-, and production-scale lyophilizers (scale-up) has been examined. Notably, the scale-up of lyophilization requires the preservation of lyophilization dynamics between the two scales, i.e., the operation of lab- or pilot-scale lyophilizer under HEPA-filtrated airflow condition. The design space determined by focusing on the primary drying stage is large and involves the undesired variations in the quality of final products due to the heterogeneous size distribution of ice crystals. Accordingly, the control of the formation of the ice crystal with large size gave impact on the product quality and the productivity although the large water content in the final product should be improved. Therefore, the lyophilization should take into account the quality by design (QbD). The monitoring method of the quality of the product in lyophilization process is termed the "process analytical technology (PAT)." Recent PAT tools can reveal the lyophilization dynamics to some extent. A combination of PAT tools with a model/scale-up theory is expected to result in the QbD, i.e., a quality/risk management and an in situ optimization of lyophilization operation.

DOI： 10.1155/2019/9502856

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The hydrolysis of disaccharides was conducted using a microcapillary system under hydrothermal conditions (up to 190°C at 10 MPa and pH 4-11). The hydrolysis reaction showed a sigmoidal progression with time, especially under alkaline conditions. Analysis using a kinetic model yielded the reaction induction period. The specific pH value (pHamb) at the induction time, which is the pH value corresponding to the progression of disaccharide hydrolysis, was peculiar to each disaccharide. Finally, the calculation of the electron density around the oxygen atom of the glycosidic bond between saccharides was found to roughly predict the pHamb value required for the progression of hydrolysis.

DOI： 10.1155/2019/3985915

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

The objective of this study is to design primary drying conditions in a production lyophilizer based on a pilot lyophilizer. Although the shelf temperature and the chamber pressure need to be designed to maintain the sublimation interface temperature of the formulation below the collapse temperature, it is difficult to utilize a production lyophilizer to optimize cycle parameters for manufacturing. In this report, we assumed that the water vapor transfer resistance (Rp) in the pilot lyophilizer can be used in the commercial lyophilizer without any correction, under the condition where both lyophilizers were operated in the high efficiency particulate air (HEPA)-filtrated airflow condition. The shelf temperature and the drying time for the commercial manufacturing were designed based on the maximum Rp value calculated from the pilot lyophilizer (1008 vials) under HEPA-filtrated airflow condition and from the vial heat transfer coefficient of the production lyophilizer (6000 vials). And, the cycle parameters were verified using the production lyophilizer of 60000 vials. It was therefore concluded that the operation of lab- or pilot-scale lyophilizer under HEPA-filtrated airflow condition was one of important factors for the scale-up.

DOI： 10.1248/cpb.c18-00516

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

The freezing stage cannot be directly controlled, which leads to variation in product quality and low productivity during the lyophilization process. Our objective was to establish a robust design space for the primary drying stage using ice nucleation control based on the pressurization and depressurization technique. We evaluated the specific surface area (SSA), water content, scanning electron microscopy (SEM) images, and water vapor transfer resistance of the dried layer (Rp) of the products. The ice nucleation control resulted in a reduction of the SSA value and in an increase in water content. SEM observation suggested that the ice nucleation control enabled formation of large ice crystals, which was consistent with the reduction in the Rp value. As a result, the generation of collapsed cakes was inhibited, whereas 18% of the collapsed cakes were observed without ice nucleation control. Finally, this technique succeeded in determining a robust design space for the primary drying stage to produce uniform products of higher productivity. It was considered, from the present findings, that controlling the formation of large ice crystals impacted the product quality and productivity.

DOI： 10.1248/cpb.c18-00494

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

Reverse micelles are thermodynamically stable systems, with a capacity to encapsulate hydrophilic molecules in their nanosized core, which is smaller than the core generally obtained with water-in-oil-emulsion droplets. Herein, we present a simple technique for the preparation of poly(ethylene glycol)-block-polylactide (PEG-b-PLA) nanocapsules encapsulating a hydrophilic photosensitizer (indocyanine green, ICG), which exploits reverse micelle formation and subsequent emulsion-solvent diffusion. We establish the effect of the PEG-b-PLA composition and the co-surfactant volume on the diameter and water content of the reverse micelles. We demonstrate that the composition of PEG-b-PLA affects also the diameter and encapsulation efficiency of the resulting nanocapsules. We show that the ICG-laden nanocapsules fabricated under the most optimal conditions have a diameter of approximately 100 nm and an ICG encapsulation efficiency of 58%. We believe that the method proposed here is a promising step towards the preparation of hydrophilic drug-laden polymer nanocapsules with a small diameter and therefore suitable for use in drug delivery applications based on enhanced permeability and retention (EPR) effect-driven passive targeting.

DOI： 10.1016/j.colsurfa.2017.02.039

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Torrefaction is a promising pretreatment process to convert biomass into high energy density solid fuel for further thermal conversion systems. In this study, the effects of wet and dry torrefaction on the properties of solid fuels prepared from bamboo and Japanese cedar were investigated in a batch reactor. The yields of solid fuels decreased with increasing treatment temperature in both torrefaction processes, mainly due to the decomposition of cellulose and hemicellulose. Cellulose showed higher reactivity than hemicellulose in both biomasses. The higher heating values (HHV) of solid fuels prepared at the treatment temperatures higher than 240 °C in both torrefaction processes reached the same level as those of commercial coals. Wet torrefaction was better than dry torrefaction for decomposing bamboo and Japanese cedar. Dry torrefaction had more favorable impact than wet torrefaction on improving the fuel properties of bamboo and Japanese cedar because of its lower energy input, higher solid fuel yield, higher energy yield, and similar HHV under the same conditions. The crystalline structure of solid fuel had no great change below 260 °C in both torrefaction processes and was completely destroyed at 300 °C during dry torrefaction.

DOI： 10.15376/biores.12.4.8629-8640

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The release behavior of substrates encapsulated in the vesicle can be controlled by the interaction between the vesicular membrane and the protein. However, its control mechanism is still now unknown. Therefore, the proteinvesicle interaction was investigated by a A isotherm. It was clarified that the released amount of encapsulated substrates increased with increasing proteinvesicle interaction. This result leads to the development of drug delivery systems (DDS) and of biosensor technology.

DOI： 10.1246/cl.170119

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

A dehydration of fructose in the water/methyl isobuthyl ketone (MIBK) biphasic system can yield 5-hydroxymethylfurfural (HMF) to be successfully extracted into the organic MIBK phase. The HMF production and yield in MIBK phase was discussed by using a simplified model taking into consideration of the slug flow. The extraction resistance of HMF across the interface between water and MIBK depended on the line velocity and the flow rate ratio. It was likely that the velocity field generated in the slug flow contributed to an increase in the mass transfer of HMF.

DOI： 10.1002/aic.15201

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Woody thin boards were prepared from lignin, cellulose, and water by compression molding at 180°C and 25 MPa for 10 min. Boards with higher contact angles gave lower values of relative permittivity on their surface. Attenuated-total reflection Fourier transfer infrared spectroscopy suggested that more lignin existed on the surface of the boards with the high contact angle, which was also supported by scanning electron microscopy and atomic force microscopy. Our findings thus revealed that the orientation of lignin at the surface resulted in increased hydrophobicity of the surface and contributed to the enhancement of water repellency.

DOI： 10.1016/j.apsusc.2015.03.139

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Wet torrefaction is an effective process to improve the fuel properties of a biomass. However, different biomasses have different component weight ratios and it is possible that not all biomasses are suitable for wet torrefaction treatment. Here we conducted wet torrefaction using three types of biomass with different component weight ratios: Humulus lupulus (HL, the common hop), Plumeria alba (PA, an evergreen shrub) and Calophyllum inophyllum L. (CIL, an evergreen tree). The fuel properties of the obtained solid fuels were characterized. We found that lignin made the main contribution to the solid fuel yield. The reactivity of cellulose and hemicellulose in each biomass was affected by the biomass species and the component weight ratio of the biomass. The wet torrefaction was observed to efficiently elevate the fuel properties of carbon content, atomic H/C and O/C ratios, higher heating value (HHV) and hydrophobicity of all three types of biomass. The HHVs of the solid fuels prepared at 260 °C are comparable to those of commercial coals such as Northumerland No. 81/2 Sem. Anth. Coal, Jhanjra Bonbahal Seam Coal-R-VII, and German Braunkohole lignite. These solid fuels could be co-combusted with German Braunkohole lignite without a significant change in the combustion properties of German Braunkohole lignite because of their similar atomic H/C and O/C ratios as well as HHVs. At the wet torrefaction temperature of 260 °C, the solid fuel delivered from CIL had lower HHV compared to those from HL and PA although CIL contained the highest lignin content, which has a higher HHV than those of cellulose and hemicellulose. Scanning electron microscopy images of the solid fuels revealed that wet torrefaction was able to completely destroy the biomass surface and create numerous pores and cracks on the solid fuels surface, indicating that the solid fuels have the potential to be used as a source of carbon materials such as activated carbon in addition to their use as bio-fuels.

DOI： 10.1016/j.fuel.2015.01.005

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Hydrothermal carbonization is considered to be an environment-friendly method to pretreat biomass. Therefore, hydrothermal carbonization of the husks of nuts from Carya cathayensis Sarg, at various temperatures and pHs were performed and the fuel properties of the obtained residue, water-soluble products (WSP) and acetone-soluble products (ASP) were characterized. It was found that the residue yield decreased with increasing hydrothermal carbonization temperature while the yield of total soluble products (WSP and ASP) was nearly the same. The residue and total soluble products yields had no large changes in the pH range of 4.0-10.0, but fewer residues and more total soluble products were obtained at pH 13.0. It was confirmed that hemicellulose was more reactive than cellulose and lignin during hydrothermal carbonization and that lignin could be effectively hydrolyzed/decomposed at pH 13.0. The higher heating values (HHVs) of residues were in the ranges of 22.0 to 28.2 MJ kg-1 at temperatures from 180 to 260 °C and pH from 4.0 to 10.0. The HHVs of these residues could be comparable with those of some commercial coals, such as lignite. However, the HHVs of residues decreased when the pH reached to 13.0. The WSP and ASP showed lower HHVs compared with heavy fuel oils, which meant the HHVs of WSP and ASP should be increased before being applied as bio-fuels.

DOI： 10.1021/acssuschemeng.5b00103

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The encapsulation of O/W emulsion droplets in a freeze-dried amorphous sugar matrix was investigated, focusing on the impact of the molecular structure of the emulsifying surfactant. O/W emulsions, containing various surfactants, were freeze-dried in the presence of a sugar. Thirty types of surfactants, including eighteen different sugar surfactants and ten types of commercially available sugar ester mixtures, were used. Linoleic acid methyl ester and trehalose were used as the oil phase and sugar. The amounts of oil droplets encapsulated in freeze-dried amorphous sugar matrix were analyzed by Fourier transform Infrared spectroscopy. Sugar surfactants were generally superior to the other classes of surfactants for oil droplet encapsulation during freeze-drying, and there was the optimum alkyl chain length of the sugar surfactant. Sugar esters generally exhibited greater oil encapsulation than sugar ethers. Larger sugar head group appeared to result in better encapsulation in the case of sugar esters, but the opposite tendency was found for sugar ethers. A limited combination of sugar surfactants (15% sucrose mono- and 85% di-stearate) resulted in the maximum oil droplet encapsulation efficiency although these surfactants are individually quite poor in the encapsulation and other tested combinations did not improve the encapsulation efficiency relative to their individual effectiveness. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodres.2015.02.003

Web of Science

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Hydrothermal carbonization of peels of Carya cathayensis sarg (PCCS) by subcritical water or acetone- and ethanol-modified subcritical water was carried out at the temperature from 280 to 360°C and coal-like hydrochar was obtained. The hydrochar yield decreased with increasing of treatment temperature, but the higher heating value (HHV) and carbon content of hydrochar were promoted at higher treatment temperature. The HHV of hydrochar was in range of 30–46 MJ/kg with an increase from 52.4 to 127.6%, compared to the original PCCS. The HHVs of hydrochars obtained at 360°C could be comparable with those of heavy fuel oil (42.9 MJ/kg) and diesel oil (45.7 MJ/kg). The O/C and H/C values of hydrochar were similar to those of lignite and subbituminous, except the ash content. Especially, the O/C and H/C values of hydrochars prepared at 360°C could be compatible with those of bituminous. When treated with acetone- or ethanol-modified subcritical water, a synergistic effect of acetone–water or ethanol–water for hydrothermal carbonization was observed; the liquefaction rate with acetone–water or ethanol–water mixture was larger than that of water or acetone or ethanol only. There was no significant change on the O/C and H/C values and HHV on the hydrochar, although more PCCS, was decomposed when using acetone–water or ethanol–water mixture.

DOI： 10.1080/19443994.2014.931537

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Subcritical water treatment is considered an environment-friendly method to liquefy biomass to prepare valuable chemicals. Several researchers have studied the solid obtained after autohydrolysis treatment for use as reinforcement in biocomposities and was the base pulp and paper technologies. The novelty of this present research is the use of solid in the manufacture of starch foams. RESULTS: Subcritical water was used to extract hemicellulosic carbohydrate from walnut shells at temperatures from 160 to 260°C for 15min and at 200°C for various treatment times. The maximum yield was obtained at 200°C for 15min. The residue of the walnut shells obtained at the maximum carbohydrates extraction yield was used to prepare a biodegradable foam by compounding with corn starch using a technique similar to compression molding. It was found that replacing 20% of the corn starch by the residue had no deleterious effects on the density and morphology, as indicated by scanning electron microscopy. The prepared foams had a dense outer skin and a less dense interior with large, mostly open cells. The flexural strains were similar to that of foamed polystyrene and the flexural modulus and flexural stresses were larger. CONCLUSION: It was considered that the prepared biodegradable foam was a promising material to take the place of plastic products in the future.

DOI： 10.1002/jctb.4451

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

Cellulose is the most abundant nature polymer and the main component in all biomass. In this study, the degradation kinetic parameters and structure changes of microcrystalline cellulose (MCC), which served as fundamental studies for degradation of biomass in subcritical water, were investigated at the temperature range from 100 to 300 °C. The yield of the MCC residue began to decrease at 205 °C and reached the lowest value at 275 °C. However, it showed an increase at the temperature higher than 275 °C. The degradation area of MCC (205-275 °C) was separated into zones 1 and 2 with 245 °C as a boundary. The activation energy (E), pre-exponential factor (A), and reaction order (n) of MCC in each zone were 226.5 kJ mol-1, 2.3 × 1023 s-1, and 0.6 (zone 1) and 423.1 kJ mol-1, 9.0 × 1040 s-1, and 0.5 (zone 2), respectively. There showed a breaking point of 245 °C for the Arrhenius plot in the reaction area. The surface morphology of the MCC residue had no significant change below 260 °C, as indicated by scanning electron microscopy (SEM) images. However, it was completely destroyed at the temperature above 275 °C, and MCC residues with strong pore structures were obtained at higher temperatures. The structures of the crystalline region of the MCC residue below 275 °C had no significant change, although 89.2% MCC was degraded at 275 °C. However, they nearly disappeared at higher temperatures with the steeply reducing crystallinity index of MCC at the same time. As for the degradation mechanism of MCC, it was proposed that only the surface of MCC was degraded at 205-245 °C and the hydrogen and glycosidic bonds on the interior of MCC fibrils were destroyed at the temperature range from 245 to 275 °C. Finally, the remaining MCC as well as generated oligomer and monomer were further degraded at higher temperatures.

DOI： 10.1021/ef501702q

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The peels of Carya cathayensis Sarg. (PCCS) were treated under subcritical water conditions (130°C to 280 °C for 0 to 120 min). The extract from PCCS included reducing sugar, proteins, and compounds with radical scavenging activity. Addressing the reducing sugar that is a resource of bioethanol, we could maximize the reducing sugar under the subcritical water (190°C for 60 min) and obtain 0.24 g/g-sample together with 9.7 units/mg-sample of radical scavenging activity. The obtained extract was estimated to correspond to 1 L of bioethanol/100 g-sample. It was therefore considered that the treatment by subcritical water could yield reducing sugar and natural compounds with radical scavenging activity. © 2014 Korean Society of Environmental Engineers.

DOI： 10.4491/eer.2014.19.1.041

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

A simple approach to preparing monodisperse poly(d,l-lactide) (PDLLA) microcapsules with a single aqueous core is developed. The method is based on automatic water-in-oil-in-water double emulsion formation from oil-in-water single emulsion via spontaneous emulsification which voluntarily disperses part of continuous aqueous phase into the dispersed oil phase dissolving oil-soluble amphiphilic diblock copolymer, poly(d,l-lactide)-b-poly(2-dimethylaminoethyl methacylate)(PDLLA-b-PDMAEMA), followed by coalescence of tiny water droplets within the polymer droplets, coupled with quick precipitation of polymers by diluting the emulsion with water. In this study, we have investigated the effect of PDLLA to PDLLA-b-PDMAEMA ratios and flow rates of each solution during preparing the emulsion on the final morphology and the size of the microcapsules. It was found that the polymer blend ratio played a crucial role in determining internal structure of the microcapsules. The microcapsules size decreased with the increment of the flow rate ratios of the continuous phase to the dispersed phase and eventually reached 10 μm, while maintaining narrow size distribution. In addition, we have demonstrated that the microcapsules can encapsulate both hydrophilic and hydrophobic compounds during the formation. © 2014 The Royal Society of Chemistry.

DOI： 10.1039/c3ra44066d

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The clarification of the partition property of substrates in a water / organic biphasic system is useful in the development of a reaction / separation process for value-added materials, especially under high temperature and pressure conditions. In this study, the water / methyl isobuthyl ketone (MIBK) biphasic system was investigated under various temperatures (25 - 190 °C) at 10 MPa. The partitioning behavior of substrates such as furfural derivatives, amino acids, and saccharides, depended on the temperature and the flow rate ratio of MIBK to the water phase. The scale of hydrophobicity (HF) of the water / MIBK biphasic system to determine the partitioning behavior of substrates was estimated based on the partitioning behavior of amino acids. The HF value for the water / MIBK phase flow system of was greater than that for the batch system and comparable to that for conventional aqueous two-phase systems such as polyethylene glycol / dextran and liposome membrane systems. It was probably because an increase of the surface-to-volume ratio and the vortex field in the slug flow contributed to the mass transfer of substrates and their distribution.

DOI： 10.15261/serdj.21.201

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

The formation of finely monodispersed oil-in-water (O/W) emulsions under high temperature and pressure conditions (240 °C and 10 MPa) depended on the solubility of the oil in water. Fatty acids with large solubilities in water favored the formation of oil droplets in emulsions of less than 100 nm in diameter. The water dissolved in the oil droplets participated throughout the cooling process, followed by the break-down of the oil droplets. In contrast, organic solvents with lower solubilities in water formed oil droplets in emulsions that had at most a diameter of 300 nm.

DOI： 10.15261/serdj.21.223

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

A finely monodispersed oil-in-water (O/W)emulsion was obtainedunder high temperature and pressureconditions(240 °C and 10 MPa). A coarse emulsion stabilized by Tween 20 was prepared in advance from the decane/water system to be treated under the subcritical conditions. The treated coarse emulsion was thereafter mixed with the aqueous solution including surfactants to improve the monodispersity of the oil droplets. The subcritical condition could supply sufficient energy to produce finely dispersed oil droplets (~233 nm in diameter).

DOI： 10.15261/serdj.21.103

Scopus

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

A rapid conversion of glycerol to lactic acid (lactate) could be successfully achieved under alkaline hydrothermal conditions, by using a continuous flow reaction system. A rapid conversion by a continuous flow-type reaction system made it possible to achieve the reaction under high-temperature conditions without side reactions. The rapid conversion and high reaction yield (reaction: 2min; yield: 90%) resulted from the rapid temperature-shift advantageous for the inhibition of side reactions. © 2014 The Chemical Society of Japan.

DOI： 10.1246/cl.131160

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

We describe a versatile and facile route to the continuous production of monodisperse polylactide (PLA) microcapsules with controllable structures. With the combination of microfluidic emulsification, solvent diffusion, and internal phase separation, uniform PLA microcapsules with a perfluorooctyl bromide (PFOB) core were successfully obtained by simply diluting monodisperse ethyl acetate (EA)-in-water emulsion with pure water. Rapid extraction of EA from the droplets into the aqueous phase enabled the solidification of the polymer droplets in a nonequilibrium state during internal phase separation between a concentrated PLA/EA phase and a PFOB phase. Higher-molecular-weight PLA generated structural complexity of the microcapsules, yielding core-shell microcapsules with covered with small PFOB droplets. Removal of the PFOB via freeze drying gave hollow microcapsules with dimpled surfaces. The core-shell ratios and the diameter of these microcapsules could be finely tuned by just adjusting the concentration of PFOB and flow rates on emulsification, respectively. These biocompatible microcapsules with controllable size and structures are potentially applicable in biomedical fields such as drug delivery carriers of many functional molecules. © 2013 American Chemical Society.

DOI： 10.1021/la403883a

Scopus

PubMed

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

5-Hydroxymethylfurfural (HMF) was obtained from the dehydration of fructose under high temperature and pressure conditions (180 °C and 10 MPa). To avoid the decomposition of HMF in the bulk aqueous phase, we dehydrated fructose in the water / metyl isobuthyl ketone (MIBK) biphasic system. The HMF could be successfully extracted into the organic MIBK phase without further decomposition of HMF. We present a simplified model taking into consideration of the slug flow with the wall film to maximize the HMF yield in the MIBK phase. It was likely that the slug flow contributed to an increase in the surface-to-volume ratio for the mass transfer of HMF.

DOI： 10.15261/serdj.20.205

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The intestinal absorption of β-1,4-mannobiose by rats was investigated. Mannobiose was detected in the portal vein plasma by matrix-assisted laser desorption ionization/time of flight mass spectrometry after its administration to rats. The presence of mannobiose in the rat plasma was confirmed by an experiment using β-mannosidase. These results indicate that mannobiose was directly absorbed through the intestines even without being hydrolyzed.

DOI： 10.1271/bbb.110731

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Monodisperse polylactide (PLA) microspheres were continuously fabricated by microfluidic emulsification and subsequent dilution in water. The diameter was precisely tuned from 6 to 50 μm by changing the flow rate of the fluids in microfluidics or the PLA concentration in the dispersed phase. The use of amphiphilic oil-soluble poly(ethylene glycol)-b-polylactide (o-PEG-PLA) as a matrix resulted in a highly porous microsphere morphology, and the porosity was controlled by blending PLA. Therefore, monodisperse PLA microspheres with the predetermined surface porosity were continuously produced by just enough reagents and energy. © 2011 The Royal Society of Chemistry.

DOI： 10.1039/c1sm05910f

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The decomposition and discoloration of powdery L-ascorbic acid in superheated steam were observed in the temperature range of 140-180 degrees C. For comparison, the decomposition and discoloration were also measured in the temperature range in hot air and at 180 degrees C in nitrogen. L-Ascorbic acid decomposed faster in superheated steam than in hot air. Discoloration was also more remarkable for the L-ascorbic acid treated in the superheated steam. The Weibull equation was applicable to the decomposition in both superheated steam and hot air. The early stage of discoloration was assumed to be expressed by zeroth-order kinetics. In the latter stage, fading occurred and the process was expressed by first-order kinetics which was modified to level off at a certain value. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.lwt.2007.11.014

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Glyceryl ferulate was synthesized by the condensation of ferulic acid with glycerol using Pectinase PL "Amano" from Aspergillus niger, which contained ferulic acid esterase, to improve the water-solubility of ferulic acid. The optimum reaction medium was glycerol/0.1 M acetate buffer, pH 4.0, (98:2 v/v). The enzyme immobilized onto Chitopearl BCW3003 exhibited the highest activity among the those immobilized onto various kinds of Chitopearl BCW resins. The optimum temperature for the immobilized enzyme was 50 degrees C, and it could be reused at least five times without a significant loss in activity for the synthesis of glyceryl ferulate in batch reaction. Storage of the reaction mixture at 25 degrees C improved the molar fraction of glyceryl ferulate relative to the dissolved ferulic residues.

DOI： 10.1007/s10529-008-9814-2

Web of Science

Scopus

PubMed

researchmap

記述言語：英語   出版者・発行元：Japanese Society for Food Science and Technology  

Wheat bran was extracted with water and subcritical water from 50°C to 260°C for 5 min. The highest extracted yield of ca. 53% on a weight basis was achieved at 200°C, at which the maximum saccharide content was also obtained. The protein, total phenolic, hydroxymethylfurfural and furfural contents were the highest at 240°C. The radical scavenging activity was also the highest at 240°C. It was demonstrated that the extract prepared at 250°C had the ability to suppress the autoxidation of linoleic acid by lengthening the induction period. The bran extracts prepared from 50°C to 200°C exhibited emulsifying activity.

DOI： 10.3136/fstr.14.553

CiNii Article

CiNii Books

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The immobilized lipase from Candida antarctica (fraction B, CALB) was incubated in glycerols with various water contents at 80-100 degrees C to measure the residual activity as a function of time. The glycerol-containing water stabilized the immobilized CALB, especially at 30-60 wt% water contents. The thermal inactivation behaviors of the immobilized CALB were expressed by a model in which the free energy of activation for the inactivation of the immobilized lipase molecules obeyed a Gaussian distribution.

DOI： 10.1007/s11746-008-1285-z

Web of Science

Scopus

researchmap

記述言語：英語   出版者・発行元：日本食品工学会  

食品成分の変質は一般に好ましくない現象であり, 品質劣化の一因となる.品質劣化の合理的な抑制法の開発には, 質的な変化に関する化学的な解明とともに, 速度論的な知見も必要である.そこで著者らは, 酸化防止剤などとして各種食品に広く使用され, 劣化しやすいことが知られているL-アスコルビン酸 (ビタミンC) の粉末状態での分解と着色について速度論的な検討を行っている.<BR>まず, 種々の含水率に調整したL-アスコルビン酸粉末の60～90℃における分解および着色過程を測定した [4] .いずれの含水率および温度でも分解過程は一次反応速度式で表現できたが, 着色過程は1次速度式が適用できず, 含水率と温度に依存して異なる最大着色度に漸近するように修正したWeibull式で表現した.また, 各過程に対する速度定数の温度依存性はいずれの含水率においてもArrhenius式で整理できた.なお, 保存温度が高く試料の含水率が高いほど最大着色度が大きかった.<BR>次に, L-アスコルビン酸の疎水性誘導体である6-O-パルミトイル-L-アスコルビン酸の消失および着色過程に及ぼす含水率と温度の影響を検討した [8] .消失過程は形状係数が約0.8の単純なWeibull式で表現でき, 着色過程はL-アスコルビン酸と同様に, 含水率と温度に依存して異なる最大着色度に漸近するように修正したWeibull式で表現できた.また, 消失および着色過程に対する速度定数の温度依存性はいずれもArrhenius式で整理できた.さらに, 同じモル比の水を含むL-アスコルビン酸と6-O-パルミトイルーL-アスコルビン酸の着色過程の比較から, 疎水性のパルミトイル基の導入はL-アスコルビン酸の着色を抑制することを示した.<BR>そこで本研究では, L-アスコルビン酸に親水性のグルコース残基を付加したL-アスコルビン酸2-グルコシドの消失および着色過程に対する含水率と温度の影響を検討した.L-アスコルビン酸2-グルコシドの消失過程も単純なWeibull式で表現でき, 速度定数kdと形状係数ndはいずれも保存温度が高いほど, また含水率が高いほど大きかった.L-アスコルビン酸2-グルコシドは, L-アスコルビン酸とグルコースに加水分解されたのち, レアスコルビン酸が他の物質に変化する逐次過程を考え, 各過程が1次反応速度式に従うと仮定して, L-アスコルビン酸量の経時変化を解析した.L-アスコルビン酸2-グルコシドの加水分解過程の速度定数klとレアスコルビン酸2-グルコシドの消失過程の速度定数kdの比較から, レアスコルビン酸2-グルコシドの消失はすべてが上述の逐次的な過程を経るのではなく, L-アスコルビン酸2-グルコシド自体の分解などにより消失する過程も並列的に進行することを示唆した.<BR>L-アスコルビン酸2-グルコシドの500nmにおける吸光度の変化は, レアスコルビン酸および6-O-パルミトイルーレアスコルビン酸と同様に, 最大吸光度A_maxに漸近するように修正したWeibull式で表現できた.A_maxは含水率が高いほど大きく, 保存温度による影響は顕著ではなかった.また, 形状係数ncも温度に依存せずほぼ2.0±0.5であった.速度定数kcは高温ほど大きく, また含水率が高い試料ほど小さかった.<BR>L-アスコルビン酸, 6-O-パルミトイルーL-アスコルビン酸およびL-アスコルビン酸2-グルコシドについて, モル基準で同程度の水 (モル比0.92～1.13) を添加した試料の70℃における着色過程を比較した.レアスコルビン酸2-グルコシドの着色過程はL-アスコルビン酸より遅く, 6-O-パルミトイルーL-アスコルビン酸より速かった.したがって, L-アスコルビン酸へのグルコース残基の導入は着色を抑制するが, その効果はパルミトイル基のそれより弱いことが示された.その理由として, L-アスコルビン酸2-グルコシドが親水的で加水分解されやすく, 生成したレアスコルビン酸が着色しやすいことが考えられる.

DOI： 10.11301/jsfe2000.9.135

CiNii Article

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The effects of sodium chloride on the degradation of hexoses at 220 degrees C and the hydrolysis of sucrose at 170 degrees C in subcritical water were examined. Sodium chloride accelerated the degradation at 220 degrees C of any hexose, especially the degradation of galactose which significantly accelerated depending on the sodium chloride concentration. On the other hand, the hydrolysis of sucrose at 170 degrees C was not affected by sodium chloride.

DOI： 10.1007/s00217-007-0788-4

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Defatted rice bran was treated with subcritical water in the temperature range of 180-280 °C for 5 min using 117 mL and 9 mL vessels to produce the extracts. The total sugar and protein contents and radical scavenging activity of the extracts were then estimated for both vessels. The total sugar concentration of ca. 0.3 g/L-extract was the highest for the extracts at 200 °C, and it significantly decreased at the higher temperatures. The protein concentration and radical scavenging activity were higher at the higher temperatures. Extraction was also done at 200 °C and 260 °C for various times using the small vessel. The total sugar concentration decreased with the increasing extraction time, while the protein concentration and radical scavenging activity only slightly depended on the extraction time. The extracts at 200 °C or lower temperatures using the large vessel possessed the emulsifying and emulsion-stabilizing activities. The HPLC analysis of the extract at 260 °C for 5 min using the small vessel indicated that it contained both hydrophilic and hydrophobic substances. The hydrophilic fraction of the extract mainly contained low-molecular-mass substances. © 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2007.11.016

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

A by-product of rice bran oil and protein production was treated with water and compressed hot water at 20 degrees C to 260 degrees C for 5 min, and at 200 degrees C and 260 degrees C for 5 to 120 min. Each extract was evaluated for its yield, radical scavenging activity,.carbohydrate, protein, total phenolic and furfural contents, molecular-mass distribution and antioxidative activity. The maximum yield was obtained at 200 degrees C. The radical scavenging activity and the protein, total phenolic and furfural contents of the extract increased with increasing temperature. However, the carbohydrate content abruptly decreased when treated at above 200 degrees C. The extract treated at 260 degrees C for 5min exhibited suppressive activity toward the autoxidation of linoleic acid. Each extract obtained at temperatures lower than or equal to 200 degrees C exhibited emulsifying ability.

DOI： 10.1271/bbb.70464

Web of Science

researchmap

記述言語：英語  

DOI： 10.1002/ceat.200700391

CiNii Article

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The mutagenicity of the extracts from defatted rice bran by water or subcritical water treatment at 50°C to 250°C was examined using the Umulac AT test, which is a kit reagent for assaying the genotoxin-induced umu gene expression. The examination revealed that the extract at any temperature was negative for the mutagenicity for both the -S9 and +S9 tests, which assess the mutagenicity of the sample itself and its metabolites, respectively. © 2008, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe2000.9.75

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Black rice bran was treated by water and subcritical water at temperatures ranging from 20 to 260 °C for 5 min and at 200 and 260 °C for 5-120 min. The bran extracts were analyzed for their radical scavenging activity, protein and carbohydrate contents, molecular-mass distribution, antioxidation activity, emulsifying activity, and emulsion-stabilizing activity. The radical scavenging activity and the protein content of the extract were higher at higher treatment temperature. The carbohydrate content also increased with increasing temperature up to 200 °C, then steeply decreased at the temperatures higher than 200 °C. The bran extracts treated at 260 °C for 5 min exhibited a suppressive activity toward autoxidation of linoleic acid with the increasing the weight ratio of the bran extract to linoleic acid. The bran extracts prepared at 40-200 °C for 5 min showed the emulsifying- and emulsion-stabilizing activities, while the extracts prepared at 220-260 °C were low in the activities. © 2007 Swiss Society of Food Science and Technology.

DOI： 10.1016/j.lwt.2007.01.003

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

L-Ascorbic acid (vitamin C) was freeze-dried along with the following six types of wall materials: soluble soybean polysaccharide (SSPS), gum arabic (GA), maltodextrin (MD), alpha-cyclodextrin (alpha-CD), trehalose (Tre) and lactose (Lac). alpha-CD, Tre and Lac were used in mixtures with MD (weight ratio of 1:1). The decomposition kinetics of L-ascorbic acid in these powders stored at 80 degrees C and relative humidities of 11, 51 and 79% were expressed by the Weibull equation. The discoloration of the powders was also monitored by measuring the absorbance at 500 nm for solutions which were obtained by dissolving the systems in water. The L-ascorbic acid powders prepared with GA and SSPS were significantly discolored and the processes could be expressed by a modified Weibull equation. The discoloration of the L-ascorbic acid powders prepared with other saccharides was very slow. The discoloration rate constants were significantly greater at temperatures higher than the glass transition temperatures of the saccharides under the stated storage conditions, while the decomposition rate constant was only slightly affected by the system glass transition temperature. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ifset.2007.02.003

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Defatted rice bran was extracted with water and subcritical water at 50-250°C for 5 min. The highest extract yield was achieved at 200°C, at which the maximum amounts of protein and carbohydrate were also obtained. The total phenolic and furfural contents, radical scavenging activity, and antioxidative activity for the autoxidation of linoleic acid increased with increasing treatment temperature. The bran extracts exhibited emulsifying activity except for the extract prepared at 250°C, which was concomitant with the disappearance of its high-molecular-mass substances. The extract prepared at 200°C also had the highest emulsion-stabilizing activity. © 2007 American Chemical Society.

DOI： 10.1021/jf072041l

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KARGER  

Mannose, fructose and glucose were treated in subcritical water at 220 degrees C, and the disappearance of each substrate and formation of other hexoses were observed at various residence times in a tubular reactor. Isomerization of mannose to fructose occurred most frequently, followed by mannose to glucose; no isomerization of glucose to mannose was observed. The temperature dependencies of mannose disappearance, the isomerization of mannose to fructose and glucose, and the resulting degradation of the produced fructose and glucose were observed in the range of 180 to 240 degrees C. The activation energy and frequency factor for each process were evaluated according to the Arrhenius equation, and it was found that the enthalpy-entropy compensation for the processes was maintained.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KARGER  

The discoloration of L-ascorbyl 6-palmitate, with water contents ranging from 2 to 10% (w/w) during storage at temperatures of 60 to 90 degrees C, was investigated by monitoring the absorbance at 500nm of its solutions dissolved in methanol. The discoloration process of the substrate was expressed by the modified Weibull equation under all conditions, and the kinetic parameters were evaluated. The activation energy and frequency factor were estimated based on the Arrhenius equation for the substrates of various water contents, and the enthalpy-entropy compensation held for the discoloration process. Comparison of the discoloration kinetic parameters for L-ascorbyl 6-palmitate with those for L-ascorbic acid revealed that the discoloration of L-ascorbyl 6-palmitate was weaker than that of L-ascorbic acid.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The optimum conditions for subcritical water treatment to produce an extract with a high phenolic content and radical scavenging activity from defatted rice bran were determined using response surface methodology. The effects of the weight ratio of bran to water from 0.05 to 0.2 and treatment time from 20 to 120 min on the total phenolic content and DPPH radical scavenging activity were evaluated using the Design-Expert program. Both the total phenolic content and DPPH radical scavenging activity increased with an increase in the bran/water ratio, but decreased with the treatment time. The optimum bran/water ratio and treatment time were 0.2 and 20 min, respectively, to attain a relatively highest total phenolic content and DPPH radical scavenging activity. © 2007, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe2000.8.311

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Saturated and unsaturated fatty acids were condensed with trehalose using Candida antarctica lipase in an organic solvent to synthesize the corresponding monoacyl trehaloses. Their surface tension curves were measured at various concentrations and at different temperatures. The critical micelle concentrations, CMC, surface tension at the CNIC, gamma(CMC) and residual area per molecule, a, were estimated from the curves. The CMC of the saturated acyl trehaloses decreased as the acyl chain length increased at all temperatures. There was no significant dependency of the gamma(CMC) value on the chain length. The CNIC values of the unsaturated monoacyl trehaloses having 18 carbon atoms in the acyl chain increased as the degree of unsaturation of the acyl chain increased. The a values were not affected by both the acyl chain length and the degree of unsaturation of the chain. (c) 2005 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.lwt.2005.11.006

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

A coarse oil-in-water (O/W) emulsion, the oil phase of which was octanoic acid, was prepared at a very low surfactant concentration using a rotor/stator homogenizer. The emulsion was passed in a stainless steel tube immersed in an oil bath at 220 degrees C at a residence time of 60 s, and then mixed with the surfactant solution to produce a finely dispersed emulsion. The diameter of oil droplets in the fine emulsion was ca. 40 nm at the weight ratio of surfactant to oil of ca. 0.35 or higher. (C) 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.lwt.2006.09.004

Web of Science

researchmap

出版者・発行元：公益社団法人 化学工学会  

DOI： 10.11491/scej.2007f.0.772.0

CiNii Article

researchmap

記述言語：英語   出版者・発行元：ELSEVIER SCIENCE BV  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

The hydrolysis kinetics of trisaccharides consisting of glucose, galactose, and fructose residues with different glycosidic bonds, 1-kestose, D-melezitose, D-raffinose, and lactosucrose, in subcritical water were conducted over the temperature range of 150-230 degrees C and at a constant pressure of 10 MPa. The hydrolysis of trisaccharides in subcritical water proceeded consecutively, i.e., one cleavage of the two bonds antedated the other. The preceding cleavage was not expressed by the first-order kinetics, but by the kinetics considering the concentration of the acidic compounds, which were produced by the degradation of the constituent monosaccharides. The hydrolysis of the constituent disaccharides, except sucrose composed of the alpha-Glc-(1 -&gt; 2)-beta-Fru bond, obeyed first-order kinetics. All of the rate constants of the hydrolytic kinetics were determined, and the values were found to depend on the type of bond.

DOI： 10.1021/bp060086l

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

1-Pentyl, 1-hexyl and 1-heptyl ferulates were continuously synthesized at 60-90°C using a reactor system in which a column packed with ferulic acid powders and another column packed with immobilized Candida antarctica lipase particles were connected in series. Conversions greater than 0.9 were achieved for the synthesis of the 1-hexyl and 1-heptyl ferulates at 90°C. The system could be stably operated for the 1-heptyl ferulate synthesis at 90°C for at least two weeks. © Springer Science+Business Media B.V. 2006.

DOI： 10.1007/s10529-006-9113-8

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KARGER  

6-O-Monolinoleoyl trehalose synthesized by the immobilized-lipase-catalyzed condensation of linoleic acid and trehalose was dissolved in water at various concentrations, and its oxidation processes were then measured at 35 degrees C based on both the decrease in the linoleoyl residue and oxygen consumption. The stoichiometric coefficient of oxygen to the linoleoyl residue was in unity except during the late stage of the oxidation. The oxidation process could be expressed by the rate equation of the autocatalytic type. The rate constant was higher for the higher substrate concentration, but it was not in proportion to the concentration at substrate concentrations higher than its critical micelle concentration. These results suggested that the migration of oxygen into the hydrophobic core of the linoleoyl residues through the hydrophilic trehalose layer of the linoleoyl trehalose micelles affected the overall oxidation rate of the linoleoyl residue.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The thermal inactivation of immobilized lipase from Candida antarctica in 1-alcohols with four to eight carbons at various temperatures could be well expressed using a model in which heterogeneity in the susceptibility of the enzyme to the inactivation was assumed. It was found that the enthalpy-entropy compensation held for inactivation in 1-alcohols. © 2006 The Society for Biotechnology, Japan.

DOI： 10.1263/jbb.102.66

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Fine W/O/W emulsions having controlled median diameters between 0.7 and 30 mu m were prepared using octanoic acid triacylglycerol (C8:0TG) and soybean oil as the oil phases. Transport enhancement of a model hydrophilic compound by the soybean-oil hydrolysates was investigated using Caco-2 model intestinal epithelial cells. The results were compared with those from in vivo experiments; in which rats were administered various types of W/O/W emulsions encapsulating insulin. Transport enhancement effect of the emulsions was evaluated by the blood-sugar level collected from the coccygeal vein. The pancreatic lipase-catalyzed hydrolysates of soybean oil showed high transport enhancement effects in Caco-2 model system, but the administration of insulin included in the W/O/W emulsion prepared with soybean oil had no hypoglycemic effect on rats. The transport enhancement effect of the hydrolysates of soybean oil in Caco-2 model system was attenuated by the coexistence of a coating material used in spray-drying process or triacylglycerol. On the other hand, administration of the W/O/W emulsions prepared with C8:0TG and encapsulating insulin showed a hypoglycemic effect on rats. Administration of the W/O/W emulsion having an oil-droplet median diameter of 2.3 mu m also showed the hypoglycemic effect in the earlier period than that of the coarse W/O/W emulsion having a diameter of 38 mu m. However, the emulsion with the diameter of 0.7 mu m exhibited no effect. These results suggested that the transport enhancement effect of the W/O/W emulsion prepared with C8:0TG depended on the size of the oil droplets, while too fine an emulsion had no such effect. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodhyd.2005.05.002

Web of Science

researchmap

記述言語：英語   出版者・発行元：日本食品工学会  

DOI： 10.11301/jsfe2000.7.147

CiNii Article

CiNii Books

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The kinetics of the hydrolysis of maltooligosaccharides with a degree of polymerization (DP) of 3-6 in subcritical water was studied using a tubular reactor at temperatures between 200 and 260°C and at a constant pressure of 10 MPa. The maltooligosaccharide disappearance and product formation at residence times shorter than 50 s could be expressed by first-order kinetics. The rate constants for the hydrolysis of each maltooligosaccharide were evaluated. There was a tendency that the exo-site glucosidic bond was hydrolyzed faster than the endo-site one irrespective of the DP of the maltooligosaccharide. The hydrolysis of the maltooligosaccharides was consecutively preceded, and the time dependence of the hydrolysis for maltooligosaccharides with different DPs could be calculated by simultaneously solving the mass balance equations for all the possible saccharides. © 2006 American Chemical Society.

DOI： 10.1021/jf060117s

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

The decompositions of monocaprylin, monocaprin, monolaurin and their corresponding fatty acids in subcritical water were measured under temperature-programmed heating conditions where the reaction temperature was linearly increased from room temperature to 350 degrees C at specified rates to estimate the activation energies E-i and the frequency factors k(i0) for the decompositions. The decompositions of both monoacyl glycerol and fatty acid obeyed first-order kinetics, and the decomposition of a monoacyl glycerol proceeded consecutively to form its constituent fatty acid and then further decomposition compounds. There was a tendency for both the E-i and k(i0) values for a monoacyl glycerol or fatty acid with a longer acyl chain to be smaller, and it was shown that the enthalpy-entropy compensation held for the decompositions of monoacyl glycerols and fatty acids as well as for those of fatty acid esters with various acyl and alkyl chains in subcritical water. (c) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodchem.2004.11.021

Web of Science

researchmap

記述言語：日本語   出版者・発行元：公益社団法人 化学工学会  

DOI： 10.11491/scej.2006f.0.414.0

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Hydrolysis of trisaccharides consisting of different monosaccharides, such as 1-kestose, melezitose, raffinose and lactosucrose, was performed in the subcritical water in a temperature range of 150 to 230°C at 10 MPa. The hydrolysis of each trisaccharide proceeded consecutively. For all the trisaccharides, one of the two glycosidic bonds was preferentially hydrolyzed and the produced disaccharide was then hydrolyzed. The hydrolyses of trisaccharides except when the substrate contained β-Fru(2→ 1)β-Fru or α-Glc-(→ 2)β-Fru bond and their constituent disaccharides were expressed by the first-order kinetics of the substrate concentration. The hydrolysis of maltooligosaccharides with the degree of plomerization (DP) of 2 to 6 in the subcritical water also proceeded consecutively. The first-order kinetics was applicable for the decrease of the substrate at short residence times in the tubular reactor. The changes in the concentration of the substrate and maltooligosaccharides with the DPs shorter than the DP of the substrate were calculated by solving the mass balance equations for the saccharides simultaneously. The calculated curves expressed well the experimental results at the short residence times but deviated from the results at the longer residence times. There was site-specificity in the hydrolysis, and the rate constants for exo-site glucosidic bond were slightly greater than those for the endo-site bond.

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The condensation reaction of angiotensin II and tartaric acid in water at 100-140°C proceeded without any added catalytic agent. One of the products, N-CO-tartarylangiotensin II, was confirmed by LC-MS, positive-ion MALDI-MS, and the fluorescamine method as a condensation product. The initial concentration of the substrates, temperatures, and initial pH affected the yield of the product. The higher concentrations and temperatures increased the concentration of the condensation product. The optimal pH for the condensation reaction was 3.0. The other C4 saturated dicarboxylic acids, malic and succinic acids, were also condensed by angiotensin II. © 2005 American Chemical Society and American Institute of Chemical Engineers.

DOI： 10.1021/bp050058n

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The degradation kinetics of the monosaccharides of both the aldohexose (glucose, galactose and mannose) and ketohexose (fructose and sorbose) types in subcritical water were studied using a tubular reactor in the temperature range of 180-260°C and at a constant pressure of 10 MPa. The relationship between the fraction of unreacted monosaccharide and the residence time could be expressed by the Weibull equation for all the monosaccharides at any temperature. The susceptibility to degradation was quite different among the saccharides. The activation energy and frequency factor were calculated from the Arrhenius equation and the enthalpy-entropy compensation was found to hold for the degradation of monosaccharides in subcritical water. The isokinetic temperature was similar to that for the hydrolysis of disaccharide. The conversion to 5-hydroxymethy-2-furaldehyde (HMF) and the decrease in pH of the effluent solution were measured and it was found that fructose had the highest value for both. © 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jfoodeng.2004.06.004

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The kinetics of the sucrose decomposition in subcritical water was investigated using a flow-type reactor in the temperature range of 160-200°C and at a constant pressure of 10 MPa. The decrease in pH during the decomposition was linearly related to the logarithm of the conversion and significantly affected the decomposition rate. The sucrose decomposition was expressed by a kinetic equation of the autocatalytic type, where the decomposition rate of sucrose was proportional to the product of the concentrations of the remaining sucrose and acidic compounds, the most of which originated from the reacted sucrose. The equation was applicable to the sucrose decomposition at its feed concentrations from 5-250 g/l and at different pHs. The conversion of sucrose to glucose and fructose almost stoichiometrically proceeded in the stated temperature range. It was also indicated that the pH of the reaction mixture played an important role in the sucrose decomposition in subcritical water. © 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.lwt.2004.06.005

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

A W/O/W emulsion containing octanoic acid triacylglycerol (C8TG) was prepared as a carrier for hydrophilic bioactive substances. The absorption enhancement effect of the hydrolysates of C8TG in the W/O/W emulsion was investigated by measuring the transport of a hydrophilic marker through the intestinal epithelial (Caco-2) cell monolayer. First, the concentrations of gall and lipase in an artificial digestive fluid, of which the integrity of the Caco-2 monolayer was not affected, were both determined to be 0.1% (w/v). The W/O/W emulsion including the hydrophilic marker molecule was hydrolyzed by the artificial digestive fluid and the apparent permeability of the hydrophilic marker substance was measured. In order to clarify the components affecting the transport enhancement, octanoic acid monoacylglycerol (C8MG) was mixed with a W/O/W emulsion at the same concentration as that in the emulsion hydrolyzed by the digestive fluid. The dependence of the apparent permeability on the C8MG concentration was the same for both emulsions, indicating that C8MG, hydrolyzed from the oil phase of the W/O/W emulsions, played an important role in the transport enhancement effect of the W/O/W emulsions. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodhyd.2004.07.004

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

6-O-Linoleoyl mannose, glucose and galactose were continuously synthesized in acetone using a packed-bed reactor system with immobilized-lipase from Candida antarctica. The high solubility of mannose in acetone resulted in the highest product concentration among the hexoses tested. The factors affecting the product concentration such as the linoleic acid concentration in the feed, the residence time in the reactor and the reaction temperature were examined. Although the product concentration was higher at the higher linoleic acid concentration, a concentration four times the solubility of hexose at a given temperature seemed to be proper. The product concentration became almost constant at a residence time in the reactor longer than 20 min. Linoleoyl mannose was continuously synthesized at 60 and 70°C, and the operation at 60°C was indicated to be preferable to that at 70°C for long-term steady synthesis. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2004.09.010

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Monolinoleoyl trehalose, maltose and cellobiose were synthesized by Candida antarctica lipase-catalyzed condensation in an organic solvent with a low water content. The use of a mixture of pyridine and tert-butanol as the reaction medium resulted in a high product concentration on the order of mmol/l for the synthesis of linoleoyl trehalose and maltose. The highest product concentration was achieved with the 0.4 volumetric fraction of pyridine. Linoleoyl cellobiose was also synthesized although its concentration was approximately one tenth the concentrations of linoleoyl trehalose and maltose. The surfactant properties of linoleoyl trehalose, maltose and cellobiose were measured. Among the esters, linoleoyl trehalose showed the strongest surface activity. © 2005, The Society for Biotechnology.

DOI： 10.1263/jbb.100.274

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The discoloration of L-ascorbic acid (vitamin C) powders with a water content of 1 to 10% (w/w) during storage at a temperature of 60 to 90°C was investigated by monitoring the absorbance of L-ascorbic acid solutions at 360, 450 and 500 nm. The discoloration reaction of the L-ascorbic acid powders was expressed by the modified Weibull equation under any condition. The rate constant, the shape constant and the maximum absorbance were estimated based on the equation. The temperature dependence of the rate constant was expressed by the Arrhenius equation under every storage condition, and the values of the activation energy and frequency factor increased with the increase in the water content. Although the shape constant depended on the wavelength at which the discoloration was observed, it was independent of the temperature. The maximum absorbance at every wavelength was expressed as functions of the water content of L-ascorbic acid powders and the storage temperature. These results enable us to estimate the discoloration of L-ascorbic acid powders under any condition, while the water content and the temperature would be limited in the ranges of 0 to 10% (w/w) and 60 to 90°C, respectively. © 2005, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe2000.6.289

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

A novel method for preparing a finely dispersed oil-in-water emulsion is proposed. Octanoic acid dissolved in water at a high temperature of 220 or 230 degreesC at 15 MPa was combined with an aqueous solution of a surfactant and then the mixture was cooled. When a nonionic surfactant, decaglycerol monolaurate (ML-750) or polyoxyethylene sorbitan monolaurate (Tween 20), was used, fine emulsions with a median oil droplet diameter of 100 nm or less were successfully prepared at ML-750 and Tween 20 concentrations of 0.083% (w/v) and 0.042%, respectively, or higher. The diameters were much smaller than those of oil droplets prepared by the conventional homogenization method using a rotor/stator homogenizer. However, an anionic surfactant, sodium dodecyl sulfate, was not adequate for the preparation of such fine emulsions by the proposed method. Although the interfacial tensions between octanoic acid and the surfactant solutions were measured at different temperatures, they were not an indication for selecting a surfactant for the successful preparation of the fine emulsion by the proposed method. (C) 2004 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2004.05.032

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The solubility of oleic and linoleic acids in water was measured in the range from 60°C to 230°C at 15 MPa. The solubility of oleic acid was almost the same as that of linoleic acid in this range, and the solubility of the fatty acids was higher at higher temperature. The logarithm of the solubility of the fatty acids was related to the reciprocal of the absolute temperature by a linear equation with a negative slope at temperatures above 150°C, and the enthalpy of the solution of each fatty acid in the liquid state in water was estimated to be 122 kJ/mol.

DOI： 10.3136/fstr.10.261

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KARGER  

The solubility of oleic and linoleic acids in water was measured in the range from 60 degrees C to 230 degrees C at 15 MPa. The solubility of oleic acid was almost the same as that of linoleic acid in this range, and the solubility of the fatty acids was higher at higher temperature. The logarithm of the solubility of the fatty acids was related to the reciprocal of the absolute temperature by a linear equation with a negative slope at temperatures above 150 degrees C, and the enthalpy of the solution of each fatty acid in the liquid state in water was estimated to be 122 kJ/mol.

DOI： 10.3136/fstr.10.261

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

Hydrolysis of fatty acid esters with different acyl and alkyl chains in subcritical water was examined over a temperature range of 483-543 K in a batch reactor. The concentrations of fatty acid esters were sufficiently low to assume a homogeneous reaction at every temperature. The hydrolysis of every fatty acid ester at any temperature obeyed first-order kinetics. The rate constant was observed at various temperatures, and the apparent activation energy and frequency factor were evaluated according to the Arrhenius equation for each fatty acid ester. Steric hindrance of the acyl and alkyl chains was found to increase the activation energy of the hydrolysis. The enthalpy-entropy compensation held in the hydrolysis of the fatty acid esters tested. (C) 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cej.2003.08.002

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Although the surfactant plays an important role in the preparation of a water-in-oil-in-water (W/O/W) emulsion, its concentration has been determined empirically. We investigated the location of a hydrophilic surfactant in a coarse W/O/W emulsion and a membrane-filtered fine emulsion. At first. appropriate concentrations of some hydrophilic surfactants to prepare a W/O/W emulsion were investigated from the viewpoints of the median diameter of the oil droplets and the encapsulation efficiency of a hydrophilic substance in the inner-water phase. The location of the surfactants and oil was examined for the W/O/W emulsions, prepared using polyglycerol monolaurate as a hydrophilic surfactant in the outer-phase solution at 1-10% (w/v) and octanoic acid triacylglycerol, which contained hexaglyceryl condensed ricinoleate as an oil-phase surfactant in the oil phase. The median diameter of the oil droplets in the W/O/W emulsion reached a minimum value at 3% (w/v) decaglycerol monolaurate (ML-750), and was constant over 4% (w/v). The excess decaglycerol monolaurate, that was not adsorbed on the oil-water interface was distributed to the outer-water and oil phases. The oil and hydrophobic surfactant were dissolved in the outer-phase solution at high concentrations of the hydrophilic Surfactant. These results suggest that the hydrophilic-surfactant concentration appropriate for preparing the W/O/W emulsion would be 3% (w/v) in the outer-phase solution and that the location of the components in the W/O/W emulsion would also be useful in estimating the adequate concentration of the surfactant. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2004.02.018

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

The hydrolysis of disaccharides consisting of two glucose residues or of glucose and fructose or galactose residues in subcritical water was measured using a tubular reactor at 10 MPa and 180-260 degreesC. The relationship between the fraction of remaining disaccharide and the residence time could be expressed by the Weibull equation for all the disaccharides tested at any temperature. The susceptibility to hydrolysis largely depended on the type of disaccharide, and it was found that the electrostatic potential charge of a glucosidic oxygen atom was an indication for the susceptibility of disaccharide to the hydrolysis. It was also shown that the enthalpy-entropy compensation held for the hydrolysis of disaccharides in subcritical water. (C) 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2003.08.002

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The permeability of dipeptide derivatives containing tryptophans and indole derivatives through Caco-2 cells was used as an in vitro intestinal absorption model in order to clarify structural factors which influence their intestinal epithelial permeation and metabolism. Most peptide derivatives were hydrolysed not only by the cytosolic enzymes in Caco-2 cells during permeation but also by enzymes released to the apical. solution before cell permeation. The N-terminal blocked dipeptides were more resistant to hydrolases expressed in the Caco-2 cells and indole derivatives were not entirely degraded. Based on compound concentration dependency and comparison of permeability coefficients in apical-to-basolateral and basolateral-to-apical directions, the main absorption mechanism of compounds were determined. Compounds were then classified into three groups; (1) passively transported compounds, (2) actively transported compounds and (3) compounds excreted by P-glycoprotein. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmc.2003.10.001

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

A water-in-oil-in-water (W/O/W) emulsion was prepared as a carrier system for the daily uptake of a bioactive compound using decaglycerol monolaurate and hexaglyceryl condensed ricinolate as hydrophilic and lipophilic surfactants, respectively. 1,3,6,8-Pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model compound of a bioactive substance. Membrane filtration of a coarse W/O/W emulsion prepared with a rotor/stator homogenizer produced a fine emulsion which had a mean oil-droplet diameter of &lt; 1 mum. The emulsions were stable for I week at 4 degreesC. The encapsulation efficiency of PTSA was &gt; 90%. Microscopic observations revealed that the fluorescent material in the outer-phase solution was included into the oil phase during rotor/stator homogenization. It was suggested that because the rotor/stator homogenizer was used to produce both O/W and W/O/W emulsions, some part of the outer phase solution would be included in the oil phase during the second homogenization. The fluorescence shown in the oil droplets of the coarse W/O/W emulsion was diminished after membrane emulsification. This phenomenon suggested that the included outer-phase solution was released to the outer-phase solution from the interior of the W/O/W oil droplets during the membrane emulsification. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/S0268-005X(03)00042-0

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The decomposition process of maltose in subcritical water was studied using a tubular reactor in the temperature range of 180 to 260degreesC and at 10 MPa. The formation of glucose and 5-hydroxymethyl-2-furaldehyde during the maltose decomposition was also observed. The decomposition rate of maltose was faster at higher temperatures. The rate was approximated by first-order kinetics during the early stage of the decomposition, but was accelerated and deviated from these kinetics at the later stage. The effluent pH decreased as the residence time in the reactor increased and the decrease of pH affected the maltose decomposition rate and glucose formation. Low pH of a feed solution accelerated maltose decomposition. A good correlation was obtained between the pH of the effluent and the rate constant of the first-order kinetics.

DOI： 10.1271/bbb.68.91

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

W/O/W emulsions are expected to protect bioactive substances from degradation by pancreatic enzymes. We investigated the enzymatic hydrolysis of the oil phase and release of a marker substance from the inner-aqueous phase to the outer-aqueous phase using an artificial digestive fluid. Octanoic acid triacylglycerol (C8TG) was used as the oil phase. W/O/W emulsions were prepared by two-step homogenization and succeeding membrane filtration. When the artificial digestive fluid containing lipase and gall was added to the emulsion, release of the marker substance from the inner-phase solution, oil-phase hydrolysis, and emulsion coalescence occurred in that order. When a coarse emulsion and 0.2- and 0.8-mum membrane-filtered fine emulsions were treated with the fluid for 1 h, the degrees of C8TG hydrolysis were 3.8%, 55% and 57%, the fractions of the marker substance released from the inner-water phase were 2.7%, 89% and 72%, and the median diameters of the oil droplets were changed from 32 to 23 mum, 0.71 to 27 mum, and from 2.2 to 26 mum, respectively. These results suggested that the diameter of the oil droplets in the W/O/W emulsion significantly affected the release profile of the marker loaded in the inner-water phase of the emulsion. (C) 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.conrel.2003.09.008

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

To evaluate absorption of compounds across the membrane via a transcellular route, the permeability of peptide derivatives and related compounds was measured by the parallel artificial membrane permeation assay (PAMPA). The permeability coefficients by PAMPA were analyzed quantitatively using classical QSAR and Volsurf approaches with the physicochemical parameters. The results from both approaches showed that hydrogen bonding ability of molecules in addition to hydrophobicity at a particular pH were significant in determining variations in PAMPA permeability coefficients. The relationship between Caco-2 cell permeability and artificial lipid membrane permeability was then determined. The compounds were sorted according to their absorption pathway in the plot of the Caco-2 cell and PAMPA permeability coefficients. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmc.2003.10.002

Web of Science

researchmap

記述言語：英語   出版者・発行元：公益社団法人 化学工学会  

Decomposition of disaccharides consisting of two glucose residues or glucose and fructose or galactose residues was measured using a tubular reactor at various residence time under the condition of 160 to 260°C and 10 MPa. The decomposition processes were expressed by the Weibull equation for all the disaccharides at any temperature. The susceptibility to decomposition depended on the type of glucosidic bond and was related to an electrostatic potential charge on the oxygen atom in the bond. Detail studies for decomposition kinetics were performed for maltose and sucrose. A change of pH during the decomposition intensively affected the decomposition rate, which could be also expressed by autocatalytic equation for sucrose decomposition.

DOI： 10.11491/apcche.2004.0.374.0

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KLUWER ACADEMIC PUBL  

The anti-oxidant activity of acyl ascorbates, with acyl chain lengths of 10 to 18, was measured in an intestinal epithelial cell line. All the acyl ascorbates exhibited the activity for the oxidization induced by three different types of oxidants, at levels higher than ascorbic acid. Myristoyl ascorbate was the most effective and showed activity at 3 x 10(-12) to 3 x 10(-6) M. Incubation with myristoyl ascorbate for more than 3 h was needed to sufficiently suppress the oxidization of the intestinal cell monolayers.

DOI： 10.1023/A:1026098519848

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：VERLAG Z NATURFORSCH  

L-Trp and its derivatives were used as model compounds to clarify structural factors which influence the intestinal epithelial permeation and metabolism of amino-acid derivatives. Permeability of model compounds through Caco-2 cells was used as an in vitro absorption model for human intestinal epithelial cells. The influence of compound concentration, the effects of various transporter substrates on permeability coefficients, and pH dependency of permeability coefficients were investigated. The transcellular permeability of Trp and Trp-NH2 in the direction from the apical side to the basolateral side, in which nutrients and drugs were ordinarily absorbed, declined with increasing concentration and saturated at more than 1 and 0.4 mm, respectively. The permeability coefficients for N-terminal protected Trp derivatives and Ac-Trp-NH2 showed similar and constant values in both from the apical-to-basolateral and basolateral-to-apical directions. In addition, significant inhibition of the apical-to-basolateral permeation of Trp by Leu and Phe was observed. The permeability coefficient ratio at pH 6.3 to that at pH 7.3 was explained by the ratio of the ionic form to the neutral form of the compounds. Based upon these results and the partition coefficients in the 1-octanol/water system, possible absorption mechanism of Trp and its derivatives across Caco-2 cells was proposed.

Web of Science

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The effects of medium-chain fatty acids (M(IFA) on intracellular calcium (Ca2+) levels and actin filaments in the Caco-2 monolayer were investigated, A site-dependent increase in intracellular Ca2+ levels caused by decanoic acid (C10) at 13 mM was observed by confocal laser scanning microscopy. The area in which the intracellular Ca2+ levels was increased was measured by image analysis, and increased to 11% of the total area of the monolayer within 1 minute, This was maintained far 5 minutes, and decreased thereafter, The other Ca2+FAs did not significantly increase the intracellular Ca2+ levels, Obvious morphological changes of actin filaments were induced by only C10 among C8-C14. The area in which actin filaments were depleted was also quantified, and the increase in area became significant after 40 minutes. The area of the actin-depleted spot corresponded to the area occupied by 5 to 10 cells as sell as that in which the intracellular Ca2+ level was increased. The effectiveness of only C10 suggested that the mechanism of the absorption enhancement by C10 a would be different from that by the other MCFAs, or that C10 has some additional physiological functions although the mechanism of the enhancement is the same as for:he other MGFAs.

DOI： 10.1271/bbb.65.743

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Caco-2 cell monolayers were used as a model of the intestinal epithelium to investigate the recovery profile from the transport-enhanced state induced by the transport enhancers, capric acid sodium salt (C10FANa) and capric acid monoacylglycerol (C10MG), The transepithelial electrical resistance, MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide) assay, and lactate dehydrogenase (LDH) release rate were investigated. The cell monolayer recovered depending on the concentration of the enhancer and on the exposure time, The MTT assay revealed that the cells recovered their mitochondrial dehydrogenase activity without proliferation. The cell monolayer exposed to C10FANa released LDH to both the apical and basolateral sides, but to C10MG, only to the apical side, The results were compared with those for SDS and taurocholic acid sodium salt, and the effect of C10FANa was found to be different. These results suggest that the damage by MCFA compounds is recoverable and that the recovery can be assessed by an MTT assay, but that the LDH-release behavior is different among the enhancers.

DOI： 10.1271/bbb.63.680

Web of Science

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The effects of natural and non-natural fatty acids on enhancing the absorption of a hydrophilic marker through a human epithelial cell (Caco-2) monolayer were measured to elucidate the properties of the fatty acids. Fatty acids from C9 to C14 enhanced the absorption depending on the concentration and the carbon chain length. Those fatty acids with longer chains gave a higher permeability coefficient at low concentrations and a lower toxicity than those with shorter chains. The surface energy lowering coefficient (SELC), an intrinsic physico-chemical property, and the critical micellar concentration (CMC) were good criteria for identifying the threshold concentrations of a fatty acid to significantly enhance absorption.

DOI： 10.1271/bbb.62.443

Web of Science

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS  

Medium chain fatty acids (MCFAs) are used to enhance the permeability of mucosal tissues to hydrophilic drugs, but their mechanism of action is largely unknown, In this study, the absorption-enhancing effects of the sodium salts of two MCFAs, capric acid (C10) and lauric acid (C12), were studied in monolayers of human intestinal epithelial Caco-2 cells, Both MCFAs induced a rapid increase in epithelial permeability to the hydrophilic marker molecule sodium fluorescein. Inhibition of phospholipase C and inhibition or activation of various kinases and buffering of intracellular calcium indicated that the effects on epithelial permeability were mediated through phospholipase C-dependent inositol triphosphate/diacylglycerol pathways. Surprisingly, the inositol triphosphate and diacylglycerol pathways were found to have opposing effects on paracellular permeability. Exposure to the MCFAs also resulted in a concentration dependent reduction of cellular dehydrogenase activity and ATP levels. C10, but not C12, induced redistribution of the tight junction proteins ZO-1 and occludin. These results indicate that the two MCFAs have partially different and more complex mechanisms than previously recognized, which has important implications for their use in vivo.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Using Caco-2 cell monolayers and MTT assay, the relationship between cell viability (a) and transport-enhancement effect of 1,2-dicaproin (C6DG), monocaprin (C10MG), and capric acid sodium salt (C10FANa) was examined, Transport enhancement effect was assessed by apparent permeability (P-app) of penicillin V. There was a linear relationship between (P-app-aS(a)) and (1-a) values, where S-a, was the apparent permeability for the viable cells. The apparent permeability for the damaged cells (Sd) was evaluated from the slope of the line, Each of the enhancer compounds gave a different S-d value 2.00 x 10(-4), 0.82 x 10(-4), and 0.10 x 10(-4)cm/s for C6DG, C10MG, and C10FANa, respectively, but the value was independent of its concentration for C10MG and C10FANa. C6DG would be the safest enhancer among the three compounds because of its high Sd value at the low level of cell damage. Sd could be used as a criterion for estimating the safety of enhancers.

DOI： 10.1271/bbb.62.83

Web of Science

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The transport-enhancing effects of medium-chain fatty acids (caproic, caprylic, and capric acids) and their acylglycerols (mono-, di-, triacylglycerols) were investigated by using Caco-2 cell monolayers as a model of the human intestinal epithelium. Penicillin V was used as a model for a hydrophilic bioactive compound. Among the fatty acids and acylglycerols tested, 1,2-dicaproin, monocaprin, monocaprylin, and capric acid sodium salt effectively enhanced the transport rate, whereas other substances enhanced the rate only slightly or not at all. With each of these four substance, the rate of enhancement was proportional to the concentration at low concentrations, but leveled off at high concentrations. The transport-enhancing effects were well correlated with the reduction in surface tension and with a physico-chemical parameter, denoted by the surface energy-lowering coefficient, characterizing the surface activity of a substance.

DOI： 10.1271/bbb.61.1150

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   出版者・発行元：TAYLOR & FRANCIS LTD  

Peptide mixtures with high and low Fischer's ratios (i.e., the ratio of branched-chain amino acids to aromatic amino acids), obtained from an enzymatic hydrolysate of casein, and the corresponding amino acid mixtures were intragastrically force-fed to rats. Cerebral cortex monoamines vr ere more influenced by the ingestion of the peptide than that of the amino acid mixture.

DOI： 10.1271/bbb.59.731

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BUTTERWORTH-HEINEMANN  

The beta-glucosidase-catalyzed synthesis of n-alkyl-beta-D-glucosides through the condensation of glucose and n-alcohols with alkyl chain lengths of 6 to 12 was carried out in a biphasic system, where the organic phase consisted only of an alcohol substrate. All the alcohols tested were condensed with glucose to give the corresponding n-alkyl-beta-D-glucosides. An equation was formula ted to predict the equilibrium yields of n-alkyl-beta-D-glucosides under various conditions, and its validity was experimentally verified. The equilibrium constant for the formation of n-alkyl-beta-D-glucosides was independent of the alkyl chain length and was 1.90 at 60 degrees C. The volume ratio of the organic to the aqueous phase was a factor significantly affecting the equilibrium yield. It was also shown that the synthesis at lower initial glucose concentrations effectively yielded alkylglucosides with less beta-glucobiose formation.

DOI： 10.1016/0141-0229(94)00082-3

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：BLACKIE ACADEMIC & PROFESSIONAL  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Alkyl β-D-glucosides and /i-alcohols were separated by high-performance liquid chromatography on a porou gel of a trimethylolpropane trimethacrylate homopolymer, using a mixture of water with methanol or acetonitrile as the eluent. The effect of the methanol and acetonitrile concentrations on the separability was examined, and the optimum concentration of each to separate alkyl glucosides and alcohols with alkyl chain lengths of six to twelve was determined. A model for analyzing the elution characteristics of the solutes for various levels of methanol or acetonitrile is proposed, based upon the chemical potential of the solutes and eluent at the interface between the gel and eluent phases. Conventional column chromatographic separation of an alkyl glucoside and an alcohol was also performed by using gel with a larger particle diameter. © 1994, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.

DOI： 10.1271/bbb.58.1558

Scopus

CiNii Article

researchmap

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NEW YORK ACAD SCIENCES  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：NEW YORK ACAD SCIENCES  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：NEW YORK ACAD SCIENCES  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC BIOSCI BIOTECHN AGROCHEM  

For producing peptides with definite characteristics from a casein hydrolysate treated consecutively with thermolysin and papain, the hydrolysate was separated through two chromatographic steps into four peptide groups with high or low contents of aromatic amino acids (AAA) and branched chain amino acids (BCAA). The hydrolysate was first separated into AAA-poor and -rich peptide groups (one-half and 3 to 4 times as high as the AAA content of the hydrolysate) by both a conventional batch chromatography with Sephadex G-15 and a continuous one, with the same resin, of a simulated moving-bed type. The AAA-poor peptide group was further separated into a BCAA-rich (about 1.5-fold) peptide group and another one with an increased content of hydrophilic amino acids by batch chromatography with Toyopearl HW-40S.

DOI： 10.1271/bbb1961.55.925

Web of Science

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   出版者・発行元：JAPAN SOC BIOSCI BIOTECHN AGROCHEM  

DOI： 10.1271/bbb1961.54.3331

Web of Science

PubMed

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC BIOSCI BIOTECHN AGROCHEM  

DOI： 10.1271/bbb1961.54.1433

Web of Science

PubMed

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BUTTERWORTH-HEINEMANN  

DOI： 10.1016/0141-0229(90)90099-C

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER VERLAG  

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Thermolysin-catalyzed condensation of N - (benzylxycarbyl) - glycyl - glycyl - L -phenylalanyl-L-leucine ethyl ester (Z-Gly-GlyPheLeuOEt), the precursor of the des-TyrMeucine enkephalin from N-(benzyl-oxycarbonyl)-glycyl-glycine (Z-GlyGly) and L-phenylalanyl-L-leucine ethyl ester (PheLeuOEt) was elucidated as a model reaction for the enzymatic synthesis of oligopeptides with many side reactions. In buffer solution, the yield of Z-GlyGly-PheLeuOEt was extremely low with considerable by-products. A large increase in both yield and purity became possible in the aqueous-organic biphasic system by the systematic selection of experimental conditions. © 1986, Nature Publishing Group. All Rights Reserved.

DOI： 10.1038/nbt0586-452

Scopus

researchmap

記述言語：日本語   出版者・発行元：日本膜学会  

CiNii Article

CiNii Books

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：公益社団法人 化学工学会  

DOI： 10.11491/scej.2010.0.475.0

CiNii Article

researchmap

記述言語：日本語   出版者・発行元：公益社団法人 化学工学会  

DOI： 10.11491/scej.2010.0.383.0

CiNii Article

researchmap

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本生物工学会  

CiNii Article

CiNii Books

researchmap

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：JAPAN OIL CHEMISTS SOC  

Glyceryl ferulate was synthesized through condensation of ferulic acid and glycerol at 50 degrees C in glycerols with different water contents using an immobilized lipase from Candida antarctica in a batch reactor, and condensation in the glycerol with a 7.5% (w/w) water content was shown to be the favorite. The solubility of ferulic acid was higher at higher temperature in glycerol with a lower water content. The viscosity was lower at higher temperature for the glycerol with a higher water content. The condensation was carried out using a batch reactor at a temperature from 50 degrees C to 90 degrees C. These observations indicated that the condensation at 80 degrees C in the glycerol with a 7.5% (w/w) water content was the most adequate for continuously synthesizing glyceryl ferulate. A reactor system was constructed for the continuous synthesis and was steadily operated to realize a productivity of 430 kg/(m(3)-reactor(day) without any decrease in the conversion for at least 6 days.

DOI： 10.5650/jos.57.375

Web of Science

researchmap

記述言語：日本語   出版者・発行元：ソルト・サイエンス研究財団  

CiNii Article

CiNii Books

researchmap

researchmap

記述言語：日本語   出版者・発行元：社団法人日本農芸化学会  

CiNii Article

CiNii Books

researchmap

担当区分：筆頭著者   記述言語：英語   出版者・発行元：CONTROLLED RELEASE SOCIETY INC  

Web of Science

researchmap

担当区分：筆頭著者  

researchmap

担当区分：筆頭著者   記述言語：日本語   出版者・発行元：学会出版センタ-  

CiNii Article

CiNii Books

researchmap

担当区分：筆頭著者  

researchmap

記述言語：日本語   出版者・発行元：社団法人日本農芸化学会  

CiNii Article

CiNii Books

researchmap

記述言語：日本語   出版者・発行元：社団法人日本農芸化学会  

CiNii Article

CiNii Books

researchmap

記述言語：英語   出版者・発行元：Blackwell Publishing Inc.  

DOI： 10.1111/j.1749-6632.1995.tb19971.x

Scopus

researchmap

担当区分：筆頭著者   記述言語：英語   出版者・発行元：NEW YORK ACAD SCIENCES  

DOI： 10.1111/j.1749-6632.1992.tb32713.x

Web of Science

CiNii Article

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：書評論文，書評，文献紹介等  

DOI： 10.1271/nogeikagaku1924.65.1111

Web of Science

Scopus

CiNii Article

researchmap

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本醗酵工学会  

CiNii Article

CiNii Books

researchmap