Research Reports No22 Abstract (2016)

22-01

Synthesis of rare sugars and possibility for food additives

Masahiko Hayashi
Department of Chemistry, Graduate School of Science, Kobe University

Catalytic asymmetric dihydroxylation of 2,3-unsaturated sugars derived from D-galactose was carried out. When benzoyl group was used as a protecting group, D-talose was obtained predominantly, on the other hand, when bulky silyl group was used as a protecting group, D-gulose was obtained in high selectivity. These rare sugars are difficult to obtain by the previous enzymatic method. Thus, we established the method of D-talose and D-gulose efficiently in a large scale. Application of these rare sugars to healthy food and food additives will be expected.

22-02

Establish of the detected method of genetically modified wheat from noodle processing foods

Taira Miyahara1), Kosuke Nakamura2), Kazunari Kondo2), Yoshihiro Ozeki1)
pision of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology1)
pision of Biochemistry, National Institute of Health Science2)

Detection of genetically modified organisms (GMO) are mainly detected by polymerase chain reaction (PCR) to amplify internal specific DNAs. Some processed steps of commercial foods are known that their genomic DNAs were fragmented to be difficult detecting amplicon by PCR methods. In this report, investigation of DNA fragmentation of processed wheat foods by qualitative PCR with primers designed to amplify wheat specific gene for different lengths. The differential processed steps of 7 noodles were detected more than 700 bp length genomic DNA fragments. Other processed wheat foods and food additives are detected more than 400 bp length amplicons. These results indicated that wheat noodles were exposed with heat, pressure and mechanical treatment at very short time compared to other processed crop foods because of their large surface area. This might occur gentle DNA fragmentation. In contrast, in Japanese confectionary kuzumochi that processed lactate fermentation over a year, shorter than 300 bp amplicons were detected. Although long fermentation caused deep DNA fragmentation, these processed wheat foods were remained 200 bp genomic DNA length after processed steps. Therefore, processed wheat foods investigated in this report could be adopted by official methods for detection GMO genomic DNA with ca. 100 bp amplified primer designed.

22-03

Analysis of Polar Natural Food Additives based on
Hydrophilic Interaction/Partition Coefficient

Koichi Inoue
College of Pharmaceutical Sciences, Ritsumeikan University

In this study, the multi-analysis of polar natural food additives was developed based on hydrophilic interaction/partition coefficient concept. Firstly, RPLC was used for the multi-analysis of Carthamus yellow, and partition coefficient was calculated using same peaks from this method. Then, high-speed cuntercurrent chromatography (HSCCC) was applied to the separation of Carthamus yellow using a two-phase solvent composed of tert-butyl methyl ether/n-butanol/acetonitrile/0.5% aqueous trifluoroacetic acid solution (2/2/1/5, V/V). HSCCC fractions were analyzed using various LC columns with RP and HILIC modes. These results present a successful application of multi-analysis of various natural materials based on hydrophilic interaction/partition coefficient concept.

22-04

Development of physical-chemical information retrieval system for food additives II

Naoki Sugimoto
pision of food additives, National Institute of Health Sciences

From the spectral database on an aging server PC which Dr. Yoshihira research group in University of East Asia had measured NMR, IR UV/Vis spectra of over 200 food additives, we had extracted the datasets and rebuilt up new retrieval database system. We also were added about 450 of quantitative NMR (qNMR) spectra to improve the spectral database. As the result, the new spectra database including 730 datasets of food additives and the related compounds has been updated and opened on our web site which any researchers are able to access the database through internet. As next project, we built up another database system that stored the specifications of food additives. Considering the system design to manage the specifications, the descriptions such as definition, identification test, purity test etc. were listed out and the dataset was associated with each item name and the prefix number. After finishing input of data, we will link the specification database to the spectral database.

22-05

Isolation and identification of fungi causing the fumonisin contamination in the Japanese domestic wines, and a study on the mechanism of fumonisin contamination.

Hiroyuki Nakagawa1, Ruiko Hashimoto2, Yoshiki Onji3, Youhei Kitaoka3
1 National Agriculture and Food Research Organization (NARO), Food Research Institute, 2 Chiba Prefectural Institute of Public Health,
3 Nara Institute of Health Science

Strains of Fusarium sp. fungi isolated from a Japanese domestic winery were examined for the gene similarity based on the β-tubulin sequence with the type strains of Fusarium sp. isolated from rice and wheat. Their fumonisin production was studied after the cultivation on rice medium. Further, a strain with higher fumonisin production on rice medium was selected, and inoculated on grape berries to investigate the infection activity and fumonisin production on the fruit.

22-06

Consumer's Attitudes toward the Safety of Food Additives

Masakazu Horie
Department of Food Science, Faculty of Home Economics,
Otsuma Women's University

We have been conducted a lecture on "risk assessment and effectiveness of the food additive" to students 148 people put enrolled in nutritionist-dietitian course, which is a representative of the consumer. Through this lecture understanding of the students of food additives it was investigated whether the degree to which change. As a result, it was found to be effective in understanding of food additives students. Also, we collected "the attitude survey for the safety of the food additive" that has been carried out in other countries, were compared with Japan.

22-07

Study on mechanisms of acceleration and suppression of oxidation by ascorbic acid and its acyl derivative in aqueous food

Yoshiyuki Watanabe
Department of Biotechnology and Chemistry, Faculty of Engineering,
Kindai University

The kinetic analysis of catechin oxidation under various conditions was conducted to elucidate mechanisms of its acceleration and suppression by L-ascorbic acid and its acyl derivative in aqueous solution. (+)-Catechin oxidation was suppressed in the presence of ascorbic acid at all tested temperatures, although no correlation was observed between the ascorbic acid suppressive effect and concentration. The rate constant for 1 mmol/L catechin oxidation increased when the ascorbic acid concentration was >10 mmol/L. The results indicated the presence of a point at which the unmodified ascorbic acid concentration led to acceleration rather than the suppression of catechin oxidation. This point was higher than that of octanoyl ascorbate.

22-08

Elucidation of carcinogenic mechanism of the nongenotoxic liver carcinogen dammar resin in rats

Hideki Wanibuchi
Osaka City University Graduate School of Medicine,
Department of Molecular Pathology

Dammar resin is a food additive primarily used as a thickening agent. We previously demonstrated that dammar resin is a hepatocarcinogen in a two-year rat carcinogenicity study and revealed that it is negative for mutagenicity in gpt delta rats. The purpose of this study is to clarify the mechanisms underlying the liver carcinogenesis induced by dammar resin in rats. Six weeks old F344 rats were pided into 2 groups and were fed diet supplemented with dammar resin at doses of 0, 2% (carcinogenic dose), for 4, 13, 32 or 52 weeks. Overexpression of Cyp2b1, 2b2, 2c6, 2e1, 3a1 and 3a2 were observed in the dammar resin administrated group. Furthermore, activities of Dnmt1 that is necessary for methylation maintenance, Dnmt3a and 3b that are involved in de novo methylation were decreased. We also found that dammar resin increased the expression level and the DNA binding activity of Myc. These finding suggest that dammar resin may cause the genome wide hypomethylation. Moreover, activation of the nuclear receptors whereby lead to CYPs induction may play an important role in the dammar resin-induced hepatocarcinogenesis.

22-09

Effects of non-caloric sweeteners consumption in early stage of life on microbiome and systemic metabolism

Takashi Uebanso
Department of Preventive Environment and Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School

Non-caloric artificial sweeteners (NAS) could provide sweet taste without enough energy unlike sugar. Those were used as a alternative source of sucrose for controlling blood glucose levels in diabetic patients because it does not provide any glucose. Consumption of artificial sweeteners is increasing past decade in Japan. However, it remains unclear that effect of artificial sweetener on mammalian metabolisms, including gut bacterium. Recently, Suez J et al. indicated a possibility that saccharin consumption induces glucose intolerance through the gut dysbiosis. It is therefore, artificial sweetener may affect gut microbiota and host metabolism. We previously found that acceptable daily intake (ADI) levels (15 mg/kg body weight) of sucralose could affect gut microbiota and host cholesterol-bile acid metabolism. In the present study, we examined effect of ADI levels of acesulfame-K consumption on gut microbiota and host metabolism in mice. We also examined details of cholesterol-bile acid metabolism in sucralose fed mice. We evaluated changes in enterobacterium by PCR-DGGE and body composition in acesulfame-K. We found that acesulfame-K consumption for 70 days showed slight changes in relative liver weight and hepatic cholesterol concentration without any changes in cecum and fecal microbiota. These results suggest that daily acesulfame-K consumption is less affected on microbiota than it have been reported so far. On the other hand we found that hepatic cholic-acid concentration was increased in sucralose fed mice.

22-10

Genetic and breeding study for increase and stabilization of yield of food additive color from safflower

Tsuneo Sasanuma
Faculty of Agriculture, Yamagata University

It is essential for yield increase and stabilization of safflower petal to elucidate the petal pigment synthesis pathway and evaluate the genetic resources available for such researches. For this purpose, in this study we conducted phenotypical characterization and molecular-based phylogenetic and persity analyses of wild safflower genetic resources collected in the North Caucasia, Georgia and Kyrgyz and organ and developmental stage specific expressional analyses of the gene fragment candidate for the safflower petal pigment related gene. In the characterization of wild safflower genetic resources, we grew the 33 accessions in the experimental field of Faculty of Agriculture, Yamagata University. Based on the young plant leaf shape, we could classify the accessions into five types, and the classification of three types of the five was consistent with identification of species. Based on the AFLP analysis and sequencing of the chloroplast IGS region including the genebank accessions identified their species, it was revealed that the accessions classified into the types 1 or 2 are tetraploid Carthamus lanatus, the accessions classified into the type 3 are the A genome diploid C. glaucus, and the accession classified into the type 5 is the B genome diploid C. oxyacantha as well as cultivated safflower (C. tinctorius). The remaining one accession classified into the type 4 is reveled not to be a Carthamus species but to be a Cirsium species. persity comparison showed that the average genetic distance among the 21 C. lanatus accsessions used for the AFLP was 0.038 and that among the five accessions of C. glaucus was 0.093, indicating that genetic persity of the diploid species collected in the restricted area was higher than that of the tetraploid species collected widely from the Caucasia and Central Asia. With respect to the expressional analysis of pigment synthesis candidate gene, organ and developmental stage specific analyses of clone 3, that is isolated in the petal of normal red flower variety, was conducted. As a result, it is clarified that this gene is expressed in whole plant body such as root, stem and leaves and is also expressed continuously in flower developmental stage, i.e., bud, early flower and late flower. These results, however, might be due to the experimental incompleteness such as primer designation so that it is necessary to reconsider the results based on the redesigned experiment.

22-11

Development of the method to determine the levels of inorganic phosphorus in
processed foods, which aimed at elucidating the relationship between the
phosphorus intake and the blood level

Makiko Suzuki
Faculty of Nutrition, University of Kochi

Polyphosphates in processed foods were extracted by 10 % trichloroacetic acid (TCA) solution. The stability of polyphosphates extracted by 10% TCA did not change compared with that of water extraction. The ortho-, pyro-, tri-, and tetra-phosphates were separated by anion exchange column (Dowex 1ﾗ4, 100-200 mesh, 1ﾗ7.5 cm). Elution by linear gradient was effective at their separation. Eluted phosphates were degraded hydrolytically. Color development of phosphates in each fraction as molybdenum blue was done in order to estimate their contents photometrically. Polyphosphates more than tetra were unstable. Therefore, they should be collectively determined. Total phosphates in one variety of Pasta, as a frozen foods were determined by vanadomolybdate absorption spectrometry after dry ashing. These methods can be applied to various kinds of foods. The amount of organic phosphate can be calculated from determined the amount of inorganic phosphate and total phosphate.

22-12

The possibility of combination effects of environmental chemicals and food
additives on the expression of immunotoxicity.

SEKIMOTO, Masashi
Laboratory of Environmental Hygiene, Department of Environmental Science,
School of Life and Environmental Science, Azabu University

In this study, I examined the effects of food additives on the activation of transcriptional factor(s) and increase of expression levels of cytokine mRNA(s) by environmental chemicals in human lung cancer A549, human leukemia THP-1 and K562 cells and demonstrated the following results.
1. The 3-methylcholanthrene (MC, 1μM), an environmental chemical, caused the activation of transcription factors including aryl hydrocarbon receptor (AhR) and nuclear-factor kappa B (NF-kB) and the induction of cytokine mRNAs such as IL-1b, IL-6 and TNFa in human A549 cells.
2. Thiabendazole (TBZ), an antifungal agent, activated transcription factors (AhR and NF-kB), and enhanced the activation of these factors by low concentration of MC (0.1μM).
3. Unexpectedly, expression levels of cytokine mRNAs were not altered by the treatment of TBZ, MC (0.1 μM) and their combination in human A549, THP-1 and K562 cell lines.
These results suggest that the food additives influence the expression of immunotoxicity by environmental chemicals through the enhancement of the activation of transcription factors such as AhR and NF-kB.

22-13

Effects of chronic consumption of a non-caloric artificial sweetener on physiological mechanisms of blood glucose control and food consumption in mice.

Yasunobu Yasoshima
pision of Behavioral Physiology, Graduate School of Human Sciences, Osaka University

Consumption of caloric and non-caloric sweeteners increases in many countries. Chronic consumption of the caloric sweeteners is suggested to be a factor to induce overeating, obesity and some lifestyle diseases. Non-caloric artificial sweeteners are widely used in various foods and beverages to reduce caloric consumption. However, some literatures reported that consumption of non-caloric artificial sweeteners caused dysregulation of body weight control and feeding behavior. To address the issue, we examined whether overconsumption of a non-caloric sweetener, saccharin, affected regulation of blood glucose and insulin secretion. We also examined effects of peripheral glucose administration on food intake in mice showing overconsumption of saccharin. Our results indicated that overconsumption of saccharin affected regulation of blood glucose and insulin secretion. In addition, mice with choric saccharin consumption showed smaller reduction of food consumption when they received systemic glucose injection in comparison to naive mice. The present study suggests that chronic saccharin consumption alters regulatory mechanisms of feeding-related physiological function such as blood glucose, insulin secretion and glucose sensitivity.

22-14

Studies on the chemical structure and the mechanism for production of gardenia red

Yusai Ito
Faculty of Home Economics, Kyoritsu Women's University

Gardenia red is hydrophilic colorant produced by the addition of an iridoid glucoside, geniposidic acid, prepared from geniposide of gardenia fruits by alkali hydrolysis to a mixture of-glucosidase and hydrolyzate of proteins. The colorant is a complex of high-molecular compounds, therefore the chemical structure of red pigments and the mechanism for producing the pigments have not been elucidated. The production of gardenia red generally needs the bubbling of argon to nitrogen gas to keep anaerobic condition and the addition of citric acid. Geniposidic acid prepared from gardenia fruits hydrolysed by cellulase and then were dissolved in distilled water with Gly and ascorbic acid and heated at 90℃. The mixture turned to red and had a maximum absorption at 520 nm. The presence of Gly during the enzyme reaction produced dark brown precipitate from the reaction of genipinic acid and Gly. The addition of excess equivalent of Gly and ascorbic acid to genipinic acid under a diluted condition of genipinic acid in the reaction mixture completely depressed the production of precipitate during heating for the production of colorant. Furthermore, HPLC analysis indicated the presence of a hydrophilic red pigment in the reaction mixture.

22-15

Induction mechanism of cell proliferation contribute to the mutagenicity of estragole,
a hepatocarcinogen

Yuji Ishii
pision of Pathology, Biological Safety Research Center,
National Institute of Health Sciences

Estragole (ES) is a hepatocarcinogen in rodents. In spite of ES-specific DNA adducts being formed in a dose-dependent manner, the mutagenicity along with induction of cell proliferation was observed only at the high dose. These results indicate that induction of cell proliferation is prerequisite in the pathways leading from ES-specific DNA adducts to gene mutations and that ES at the lower dose has no potential for mutagenicity. Given that humans are actually exposed to ES at very low doses, to clarify the detailed mechanisms including molecular signaling pathways in induction of cell proliferation is very important in terms of extrapolation to humans. In this study, we examined time-dependent changes of mutagenicity-related factors in the livers of gpt delta mice treated with ES. Eleven-week-old female B6C3F1 gpt delta mice were given ES at a single dose of 300 mg/kg by gavage. The livers collected after 1, 2, 3, 5, 7 and 14 days were examined. At day 1, the level of phosphorylated p53, p38 and JNK protein increased along with the maximum level of ES-specific DNA adducts. Centrilobular hepatocyte apoptosis, cleaved caspase3 positive cells and increases in the expression of TNF gene and phosphorylated Akt and PP2A protein were observed at day 2. Together with hepatocyte mitosis, expression of PCNA positive cells and cell cycle-related genes reached maximum levels at day 3. The gpt mutant frequencies significantly increased at day 14. Therefore, activation of Akt signaling via TNF疝och might be responsible for ES-induced proliferation. PP2A inactivation also might contribute to Akt phosphorylation.

22-16

Research on diuretic action and reduction of lipogenesis in rats received high fat diet and enzymatically modified isoquercitrin

Toshinori Yoshida
Tokyo University of Agriculture and Technology, Graduate School,
pision of Animal Life Science, Institute of Agricultural Science

To determine effects of enzymatically modified isoquercitrin (EMIQ) and a diuretic spironolactone (SR) on blood lipids and intrahepatic oxidative stress, we examined blood and/or liver samples in rats fed high fat diet (HFD) subjected to a two-stage hepatocarcinogenesis model. Rats were fed with basal diet or HFD containing SR and co-administered with an antioxidant EMIQ. The HFD increased body weight and inraabdominal adipose tissue weight, and plasma total cholesterol, triglyceride, and alkaline phosphatase in blood samples as compared with the control basal diet-fed rats. Although there were no treatment-related changes in liver weight, HFD increaseｓ score of steatosis and number and area of a preneoplastic lesion, glutathione S-transferase placental form (GST-P)⁺ foci, where higher expression of a NOX component p22phox+ cells and a cell proliferation marker Ki-67+ cells were confirmed. SR treatment decreased these parameters, which were further reduced by EMIQ supplement. RT-PCR in liver tissues revealed that SR and/or EMIQ supplement reduced mRNA expression levels of lipogenic enzymes (Scd1, Fasn), anti-oxidant-related enzymes (Catalase), and NOX component (P67phox), as compared with HFD group. The results indicated that EMIQ had a potential of suppressing hyperlipidemia, liver steatosis, and preneoplastic liver lesions through improvement of intrahepatic oxidative stress and suggested that an antioxidant might have a potential of preventing obesity-related diseases.

22-17

Enhancement by food additives of the sensitivities to chemical carcinogens.

Kouichi Yoshinari
Department of Molecular Toxicology, School of Pharmaceutical Sciences,
University of Shizuoka

We have recently reported that the activation of PXR, a xenobiotic-responsive nuclear receptor, dose not induce hepatocyte proliferation by itself but enhances the liver tumor promoter- or growth factor-induced murine hepatocyte proliferation. In this study, we have investigated whether food additives show such an influences on hepatocyte proliferation through PXR activation. Among 25 food additives tested, we have identified imazalil as a potential murine PXR activator from the results on mouse PXR reporter assays and in vivo studies with mice. The results also suggest that imazalil activates CAR as well. Currently, we are investigating whether imazalil can stimulates CAR-mediated hepatocyteproliferation in mice

22-18

Screening of compounds specifically inhibiting the new menaquinon biosynthetic pathway from spices

DAIRI Tohru
pision of Applied Chemistry, Graduate School of Engineering, Hokkaido University

Menaquinone (MK) is an essential compound because it is an obligatory component of the electron transfer pathway in microorganisms. In Escherichia coli, MK was shown to be derived from chorismate by eight enzymes, designated MenA to H. However, we have revealed that an alternative pathway, we named it the futalosine pathway, was operating in some microorganisms including Helicobacter pylori, which causes gastric carcinoma. Since humans and some useful intestinal bacteria, such as lactobacilli, possess the classical pathway, and MK biosynthesis is essential for survival of microorganisms, the futalosine pathway is an attractive target for the development of specific anti-H. pylori drugs. In this study, we tried to obtain such compounds from spices.
We used two kinds of Bacillus strains as test organisms, Bacillus subtilis and Bacillus halodurans, which possess the classical and the futalosine pathway, respectively. By a paper disk assay, we found that extracts of a red pepper specifically inhibited the growth of B. halodurans. We then purified an active compound and determined its structure. Consequently, we confirmed that it was cis-linoleic acid.

22-19

Development of highly stable food dispersions using food additives
Kobayashi Isao
Food Research Institute, National Agriculture and Food Research Organization (NARO)

Many important properties of food dispersions including emulsions can be controlled by the use of food additives. Electrostatic layer-by-layer deposition is a promising method to modify the surface properties of droplets and microparticles present in food dispersions. The aim of this study was to improve stability of food-grade oil-in-water (O/W) emulsions by using the electrostatic layer-by-layer deposition method. Two oppositely charged hydrophilic polysaccharides (chitosan and calboxymethyl cellulose) were used to coat the surface of medium-chain triglyceride (MCT) oil droplets, initially stabilized by negatively charged lysolecithin. The primary O/W emulsions with a weight ratio of the dispersed phase of 20 wt% were prepared by rotor-stator homogenization and had a Sauter mean droplet diameter of 28.3 m and a relative span factor of 0.99. After the layer-by-layer deposition, the main peak of the particle size distribution was not largely shifted, while a low peak appeared due to the presence of smaller complex microparticles driven by electrostatic interaction. 詬och-potential of the primary O/W emulsion was -67.4 mV at pH 5, demonstrating that the oil droplets stabilized by lysolecithin had negative charge. 詬och-potential of the oil droplets were dependent on the charge of the hydrophilic polysaccharides which formed the most outer layer of the droplets. The electrostatic layer-by-layer deposition using oppositely charged hydrophilic polysaccharides improved storage stability of the MCT oil droplets. The findings obtained from this study could be available for designing and developing premium food dispersions whose stability and digestibility are highly controllable.

22-20

Visualization of Volatile Organic Compounds from Plant Using Odor Sensing Methods
Zhang Jian, Chuanjun Liu, Kenshi Hayashi
Department of Electronics、 Graduate School of Information Science and Electrical Engineering、 Kyushu University

In this research report, development of odor visualization from plant VOC using optical probes is described. Odor imaging technologies are developed using various optical probes which can interact with odor substances. In this research odorants from ginger are target substances to be visualized. For the purpose, optical fluorescent probes are examined which have high sensitivity to ginger odorants such as ginerone. As a result, quinine sulfide and caroxyfluoresceine have high sensitivity for ginger standard odor substance and ginger extract which as prepared using soxhlet extracting method. The extract was also examined using GC-MS analyses and various odorants were identified and inhomogeneous distribution was confirmed for odor substances from ginger sample. Finally, the explored odor image sensing method was developed using imaging films which contains examined fluorescent dyes, and odor flow from ginger odor sources could be visualized using the odor imaging system. Visualized odor distribution which consists of compressed chemical information will produce movement and distribution information within plant bodies.

22-21

Development of novel extraction and recovery methods of rare and useful food additives from natural products

Kenji Mishima
Fukuoka University

Some natural products contain rare physiologically active substances which can be employed as useful food additives, such as nootkatone contained in the pericarp of grapefruit. We have developed novel extraction and recovery methods for these rare and useful food additives from natural products. The bioactivity of the target substances extracted from natural products was evaluated by means of a brain function imaging apparatus that uses near-infrared spectroscopy (fNIRS). This brain imaging technique indirectly measures brain activity by directly measuring cerebral blood flow oxygenation levels. As a first approach, the substances from the pericarp of grapefruit, coffee beans and vanilla were extracted by conventional extraction methods, such as ethanol and water extraction. Components such as limonene, myrcene, nootkatone, cyclotene, maltol, terpenes and vanillin were isolated and analized by HPLC and GC-MS. Secondly, the same substances from natural products, i.e. pericarp of citrus, coffee beans and vanilla, were extracted by using a supercritical carbon dioxide extraction method (SC-CO2 extraction). We concluded that the SC-CO2 extraction method showed a more effective extraction performance than the conventional methods and has the additional advantage of not needing a desolvation process after extraction. Furthermore, we have proposed a more effective SC-CO2 method using supersonic irradiation.

22-22

Development of salt and sugar-limited foods whose saltiness and sweetness are enhanced by γ-glutamylation.

Hideyuki Suzuki and Yuko Nakafuji
Kyoto Institute of Technology

Protease, which accumulates more glutamine by digesting gluten, was screened and Protin SD-AY10 was chosen. The highest amount of glutamine was found when 30-mL of 3%(w/v) gluten solution was digested by 0.09 g of Protin SD-AY10 at pH 9, 37oC for 8 hr. The pH of the digested solution was adjusted to 10, and then glutaminase (GGT) was added. Peaks, which can be considered γ-glutamylpeptides, were found by HPLC analysis.

22-23

Control of dynamic characteristics and gastric digestion of gelled food for elderly people using food additives

Ichikawa Sosaku1、Kobayashi Isao 2、Kozu Hiroyuki1, 2
1Faculty of Life and Environmental Sciences, University of Tsukuba
2 National Food Research Institute, National Agriculture and Food Research Organization

As population aging advances, people suffering the gastrointestinal malfunctions are increasing. Controlling nutrient release in human gut has been more and more important in an aging society. Lipids are essential energy-supplying nutrients in three major nutrients of food. Lipids are also indispensable components for absorption of the hydrophobic ingredient and maintenance of the function of human organs in body. Therefore, development of lipids-containing foods that elderly people can take without discomfort is required. In this study, O/W emulsion gels were prepared as a model of lipids-containing foods for elderly people. Then the breakdown and oil release phenomena of emulsion gels in human stomach were investigated using in vitro gastric digestion device, i.e. Gastric Digestion Simulator (GDS) developed in our research group. Considering the situation of nutrient embedded in the solid material, O/W emulsion made of soybean oil was gelatinized using agar alone or mixture of agar, native-type gellan gam, and deacylation-type gellan gum. In the case of adding agar, gel shape was disintegrated, reducing gel particle size, and releasing oil droplets from gels by simulated peristalsis of GDS. Emulsion gel prepared by mixing agar and native-type gellan gam reduced the degree of gel disintegration and released oil amount compared to that of emulsion gel prepared with agar alone. On the other hand, gel disintegration and oil release were not observed in the case of adding deacylation-type gellan gum. The gel particles shrunk, and the water is released from the gel. These results indicate that the amount of oil release from emulsion gel to gut lumen can be controlled by choice and combination of gelatinizer. Our results provide useful fundamental knowledge for the development of lipids-containing foods for elderly people.