Study on Shrinkage Deformation of Food in Microwave-Vacuum Drying

Selected Papers from the 19th International Drying Symposium (IDS 2014), Part 2Drying shrinkage is an important problem in the food industry. Focusing on microwave vacuum drying, we study the mechanism of deformation due to shrinkage of the food structure. A relationship between the strain and the water content is introduced for a finite element analysis. The temperature and water distributions are obtained by a finite difference method with the use of a variable permeability and diffusion coefficient depending on the water content. Comparisons with experimental data on radishes, carrots, and tofu indicate that the present model can express the deformation as well as the water content inside the materials

Possibility of cryopreservation of medaka eggs using liquid meniscus

The First Pacific Rim Thermal Engineering Conference (PRTEC2016), Marchi 13-17, 2016, Waikoloa Beach Marriott Resort & Spa Hawaii's Big Island, USAThe cryopreservation of fish eggs is an important subject in the field of fishery and preservation of biological species. Thus far, there has been no success in the preservation of fish eggs because of the large size of the eggs and the thick external shell. This paper discusses the effectiveness of using the liquid meniscus formed around the egg for protecting its morphology. Freezing and thawing experiments of medaka eggs were performed under different freezing conditions, and the hatching rate of the egg was examined. Before freezing, the eggs were dehydrated at room temperature in order to reduce the effect of volume expansion caused by freezing. It was confirmed that 100% of the eggs dehydrated by 15% or less were successfully hatched. In the freezing process, a medaka egg was placed on a hydrophobic cooling plate and a thin liquid meniscus was formed around the hydrophilic egg surface. An aqueous solution of trehalose was used as the liquid meniscus as well as a cryoprotectant to prevent damage caused by freezing. Cryopreservation of the egg was not successfully performed for all processes, including intracellular freezing; however, 80% of the eggs were alive even after freezing of the external meniscus. Therefore, it is confirmed that the liquid meniscus is effective for the cryopreservation of the external shell. The liquid meniscus can reduce the physical stress due to extracellular ice growth. Moreover, since the liquid meniscus system has a low heat capacity, the thermal process is easy to control compared to the conventional method. We concluded that the present method can be used for the cryopreservation of fish eggs

Ambient temperature drying of therapeutic protein solution with use of microwave

[EN] High quality drying of therapeutic protein-solution is important in medical and pharmaceutical processing. Freeze-drying is mostly used, but it takes a long drying-time and causes damages of protein structures. In order to improve the drying quality, we propose a microwave vacuum drying performed at ambient temperatures under low-pressure conditions. We are focusing on the Parma-Zyme method for the evaporative drying of protein solutions such as egg white or lysozyme with vitrification. Circular dichroism (CD) spectroscopy is used to detect protein conformation changes due to the drying, and it is found that the ambient temperature drying can preserve the protein conformation.CD analysis and chemical works were supported by Prof. Shigeori Takenaka, Department of Applied Chemistry, Kyushu Institute of Technology. This study was financially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research, Project No. 17K18843.Tsuruta, T.; Ogawa, T.; Abe, R.; Tanigawa, H. (2018). Ambient temperature drying of therapeutic protein solution with use of microwave. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 651-658. https://doi.org/10.4995/IDS2018.2018.7537OCS65165

マウス糞便を用いた大黄甘草湯中のセンノシドA腸内代謝とHPLC定量分析(発表論文抄録(2011))

Daiokanzoto (DKT, combination of rhubarb and glycyrrhiza), a Kampo medicine, is clinically effective for constipation. Sennoside A is well known to induce diarrhea. Sennoside A is a prodrug that is transformed into an active metabolite, rheinanthrone, by intestinal bacteria. In this study, we investigated the effects of glycyrrhiza on the activity of sennoside A metabolism in intestinal bacteria using mouse feces. A high-performance liquid chromatography (HPLC) method for the determination of sennoside A in incubation mixture of DKT with mouse feces was established. The retention time of sennoside A was 9.26±0.02 min with a TSKgel ODS-80TsQA column by linear gradient elution using a mobile phase containing aqueous phosphoric acid and acetonitrile and detection at 265 nm. We found that the activity of sennoside A metabolism in intestinal bacteria was significantly accelerated when glycyrrhiza, liquiritin or liquiritin apioside coexisted with sennoside A, whereas that of glycyrrhizin was not altered. This method is applicable for determination of the activity of sennoside A metabolism by anaerobic incubation of DKT with mouse feces.Daiokanzoto (DKT, combination of rhubarb and glycyrrhiza), a Kampo medicine, is clinically effective for constipation. Sennoside A is well known to induce diarrhea. Sennoside A is a prodrug that is transformed into an active metabolite, rheinanthrone, by intestinal bacteria. In this study, we investigated the effects of glycyrrhiza on the activity of sennoside A metabolism in intestinal bacteria using mouse feces. A high-performance liquid chromatography (HPLC) method for the determination of sennoside A in incubation mixture of DKT with mouse feces was established. The retention time of sennoside A was 9.26±0.02 min with a TSKgel ODS-80TsQA column by linear gradient elution using a mobile phase containing aqueous phosphoric acid and acetonitrile and detection at 265 nm. We found that the activity of sennoside A metabolism in intestinal bacteria was significantly accelerated when glycyrrhiza, liquiritin or liquiritin apioside coexisted with sennoside A, whereas that of glycyrrhizin was not altered. This method is applicable for determination of the activity of sennoside A metabolism by anaerobic incubation of DKT with mouse feces

AVIDa-hIL6: A Large-Scale VHH Dataset Produced from an Immunized Alpaca for Predicting Antigen-Antibody Interactions

Antibodies have become an important class of therapeutic agents to treat human diseases. To accelerate therapeutic antibody discovery, computational methods, especially machine learning, have attracted considerable interest for predicting specific interactions between antibody candidates and target antigens such as viruses and bacteria. However, the publicly available datasets in existing works have notable limitations, such as small sizes and the lack of non-binding samples and exact amino acid sequences. To overcome these limitations, we have developed AVIDa-hIL6, a large-scale dataset for predicting antigen-antibody interactions in the variable domain of heavy chain of heavy chain antibodies (VHHs), produced from an alpaca immunized with the human interleukin-6 (IL-6) protein, as antigens. By leveraging the simple structure of VHHs, which facilitates identification of full-length amino acid sequences by DNA sequencing technology, AVIDa-hIL6 contains 573,891 antigen-VHH pairs with amino acid sequences. All the antigen-VHH pairs have reliable labels for binding or non-binding, as generated by a novel labeling method. Furthermore, via introduction of artificial mutations, AVIDa-hIL6 contains 30 different mutants in addition to wild-type IL-6 protein. This characteristic provides opportunities to develop machine learning models for predicting changes in antibody binding by antigen mutations. We report experimental benchmark results on AVIDa-hIL6 by using neural network-based baseline models. The results indicate that the existing models have potential, but further research is needed to generalize them to predict effective antibodies against unknown mutants. The dataset is available at https://avida-hil6.cognanous.com

Determination of paroxetine in serum treated with simple pretreatment by pre-column high-performance liquid chromatography using 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride as a fluorescent labeling reagent.

The therapeutic drug monitoring of paroxetine could be used to optimize the pharmacological treatment of depressed patients. A simple and sensitive high-performance liquid chromatography procedure was developed for the determination of paroxetine in serum. After simple pretreatment of serum (50 μL) with acetonitrile and o-phthalaldehyde, paroxetine was derivatized with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride at 70°C for 20 min in borate buffer (0.1 mol/L, pH 8.0) to produce a fluorescent product. The derivative was separated on a reversed-phase column at 40°C for stepwise elution with (A) acetic acid (10 mmol/L) and (B) acetonitrile. The flow rate was 1.0 mL/min. The fluorescence intensity was monitored at excitation and emission wavelengths of 320 and 400 nm, respectively. The within-day and day-to-day relative standard deviations were 3.0-3.4 and 2.7-8.3%, respectively. The detection limit of paroxetine was 8.3 fmol at a signal-to-noise ratio of 3. As the proposed method that only requires a small quantity of serum (50 μL) is simple, sensitive and reproducible, it would be useful for clinical and biochemical research as well as drug monitoring.The therapeutic drug monitoring of paroxetine could be used to optimize the pharmacological treatment of depressed patients. A simple and sensitive high-performance liquid chromatography procedure was developed for the determination of paroxetine in serum. After simple pretreatment of serum (50 μL) with acetonitrile and o-phthalaldehyde, paroxetine was derivatized with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride at 70°C for 20 min in borate buffer (0.1 mol/L, pH 8.0) to produce a fluorescent product. The derivative was separated on a reversed-phase column at 40°C for stepwise elution with (A) acetic acid (10 mmol/L) and (B) acetonitrile. The flow rate was 1.0 mL/min. The fluorescence intensity was monitored at excitation and emission wavelengths of 320 and 400 nm, respectively. The within-day and day-to-day relative standard deviations were 3.0-3.4 and 2.7-8.3%, respectively. The detection limit of paroxetine was 8.3 fmol at a signal-to-noise ratio of 3. As the proposed method that only requires a small quantity of serum (50 μL) is simple, sensitive and reproducible, it would be useful for clinical and biochemical research as well as drug monitoring