2022年11月, Mae Fah Luang University 4th ICAAI2022, Oral Presentation Award – Gold Medal　　　　　　　　　　　　　　　

2022年08月, International Symposium on Tea Science and Traditional Medicine Research, Best Presentation Award　　　　　　　　　　　　　　　

Simulated In Vitro Digestive Characteristics of Raw Yam Tubers in Japanese Diet: Changes in Protein Profile, Starch Digestibility, Antioxidant Capacity and Microstructure
Chuang Zhang, Sunantha Ketnawa, Sukanya Thuengtung, Yidi Cai, Wei Qin, Yukiharu Ogawa
Foods, 11, 23, 3892, 3892, MDPI AG, 2022年12月02日
研究論文（学術雑誌）, The consumption of raw yam tuber through grated yam “tororo” is a major and popular diet in Japan. However, few studies have been undertaken to evaluate the digestive characteristics of raw yam tubers. This study aimed to fill this gap by investigating the changes in the protein profile, protein and starch digestibility, antioxidant capacity and microstructure of two typical yam tubers (Nagaimo N-10 and Nebaristar) in the Japanese diet, applying a simulated in vitro digestion method. Results showed that both samples contained a considerable protein content of about 11% (dry basis) and a protein digestibility of 43–49%. The electrophoretic patterns confirmed that dioscorin was the main protein of the yam tuber, and it could be digested into peptides and free amino acids with low molecular weight during in vitro digestion. The starch hydrolysis results suggested that eating raw yam tuber cannot induce a fast glycemic increase for consumers due to a low starch digestibility of 4.4–6.1%. In addition, Nebaristar showed a higher bioaccessibility in some key amino acids and total phenolic content than the Nagaimo N-10. This study provides some essential nutritional information and simulated digestion behaviours of the raw yam tubers, which could be useful for consumers and industries when buying and processing yam tubers from the perspective of changes in the nutritional profile during digestion.

Influence of manufacturing system scale for commercial Japanese green tea (Sencha) production on biochemical characteristics of tea leaf and infusion
Wei Qin, Ryutaro Yamada, Takuya Araki, Yukiharu Ogawa
Journal of Food Process Engineering, 46, 1, Wiley, 2022年10月17日
研究論文（学術雑誌）, Abstract

Dried green tea leaves (Sencha) were manufactured using various scale manufacturing systems, which processed batch‐wise for 15 kg (15 K), 60 kg (60 K), and 120 kg (120 K) fresh leaves. Total polyphenol content (TPC) and antioxidant activity (FRAP and DPPH) of dried tea leaves and infusions were evaluated. The values of TPC, FRAP, and DPPH of dried tea leaves processed by the larger systems (120 K and 60 K) were significantly higher than the values by the smaller system (15 K). In contrast, with the larger system scale, some of the leaves were not fully rolled and were not mechanically damaged during processing. These incomplete processing conditions led to the extraction of significantly fewer polyphenols in hot water, which might influence the health benefits of green tea infusions. This study indicated that there could be an optimal system scale that considers the balance between economic and health benefits, involving the optimization of production quality/amount.

Practical Applications

After harvest, Japanese green tea leaves are gradually dried using batch‐wise processing systems. The processing system scale is permanently fixed by the size of one batch, which is selected according to the circumstances of the production area and demand for tea production. However, tea leaf producers have experientially been aware of the quality variations in the final tea products, depending on the system scale. In this study, the impact of the scale of the manufacturing system on the functional properties of green tea was investigated. The results revealed that the hot water extract of dried tea leaves processed by a larger system scale tended to have less functional properties than those by a smaller system. This was due to the comparatively incomplete rolling conditions of tea leaves processed by larger manufacturing systems. These differences influence the preservability and extractability of the chemical components of the green tea leaves. Our findings provide beneficial information regarding processing conditions for better functional green tea infusions.

Effect of digestive enzymes and pH on variation of bioavailability of green tea during simulated in vitro gastrointestinal digestion
Wei Qin, Sunantha Ketnawa, Yukiharu Ogawa
Food Science and Human Wellness, 11, 3, 669, 675, Tsinghua University Press, 2022年05月
研究論文（学術雑誌）

Changes in Morphological and Functional Characteristics of Tea Leaves During Japanese Green Tea (Sencha) Manufacturing Process
Wei Qin, Ryutaro Yamada, Takuya Araki, Yukiharu Ogawa
Food and Bioprocess Technology, 15, 1, 82, 91, Springer Science and Business Media LLC, 2021年11月24日
研究論文（学術雑誌）

Bio-properties of Saba banana (Musa ‘saba’, ABB Group): Influence of maturity and changes during simulated in vitro gastrointestinal digestion
Florencio Collado Reginio, Wei Qin, Sunantha Ketnawa, Yukiharu Ogawa
Scientific Reports, 10, 1, Springer Science and Business Media LLC, 2020年04月21日
研究論文（学術雑誌）, Abstract

Saba banana, a popular fruit crop grown in Southeast Asia, is an economical source of a variety of beneficial agents. This study examined the variations in total phenolic, flavonoid, and antioxidant activities of five maturity stages of Saba banana, and their changes during simulated in vitro gastrointestinal digestion as affected by varying structural compositions. Antioxidant activities were evaluated using ferric reducing antioxidant power (FRAP), metal ion chelating (MIC) activity, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Results of DPPH and ABTS were compared in terms of TEAC (Trolox Equivalent Antioxidant Capacity) and VCEAC (Vitamin C Equivalent Antioxidant Capacity) values. Bio-properties were found to be highest in mature green stage with values slightly decreased as ripening proceeded. Simulated digestion showed a continuous increase in total phenolic with comparatively faster release in structure-less state (slurry) than samples with intact structure (cut). The trend of antioxidant activities was increased in the gastric phase and then decreased at the onset of intestinal phase, except for MIC which showed a reverse effect. Our study indicated that the bio-properties of Saba banana were affected by maturity and modifications in its physical structure and composition could influence the release behaviors of food components during simulated digestion.

Impact of particle size of pulverized citrus peel tissue on changes in antioxidant properties of digested fluids during simulated in vitro digestion
Yidi Cai, Wei Qin, Sunantha Ketnawa, Yukiharu Ogawa
Food Science and Human Wellness, 9, 1, 58, 63, Tsinghua University Press, 2020年03月
研究論文（学術雑誌）

Effect of particle size of pulverized citrus peel tissue on elution characteristics of intracellular substances as influenced by type of solvent
Yidi Cai, Jinhu Tian, Wei Qin, Yukiharu Ogawa
Food Hydrocolloids, 100, 105392, 105392, Elsevier BV, 2020年03月
研究論文（学術雑誌）

Effect of processing step and condition for Japanese green tea manufacturing process on structural attribute of tea leaves and antioxidant activity of tea infusion　　　　　　　　　　　　　　　
Wei Qin, Yukiharu Ogawa
2018年11月

Parboiling reduced the crystallinity and in vitro digestibility of non-waxy short grain rice
Jinhu Tian, Yidi Cai, Wei Qin, Yoshitaka Matsushita, Xingqian Ye, Yukiharu Ogawa
Food Chemistry, 257, 23, 28, Elsevier BV, 2018年08月
研究論文（学術雑誌）

Washoku, Japanese Food　　　　　　　　　　　　　　　
Yukiharu Ogawa, Sukanya Thuengtung, Sunantha Ketnawa, Wei Qin, Jutalak Suwannacho, Masatsugu Tamura
2022年12月

2022年 - 現在
農業施設学会　　　　　　　　　　　　　　　

2022年 - 現在
美味技術学会