Browsing by Author "Ogawa Y"

Now showing 1 - 4 of 4
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    Characterization of flours from some underutilized carbohydrate sources of Thailand for potential food applications
    (Elsevier Ltd., 2024-05-01) Wonglek S; Jaikaew C; Ogawa Y; Singh J; Panpipat W; Donlao N
    Northern Thailand's underutilized crop flours were examined for morphology, chemical composition, thermal, and techno-functional properties to broaden carbohydrate sources and assess their potential as plant-based food analogs and other food ingredients. Samples were as follows: Elephant foot yam (A), and Purple yam or Greater yam (DA-P), Water yam (DA-W), Five-leaf yam (DP), D. daunaea Prain & Burkill (DD), and Lesser yam (DE). Scanning electron micrographs revealed varied starch granule shapes and size ranging from 9 to 31 mm. XRD showed A-type crystallinity for sample A, B-type for DA-P, DA-W, DP, and DE, and C-type for DD. DP flour has the highest protein and starch content. DD and DE flours had the highest fat and fiber content with the least amylose content. DP, DA-P, and A flours displayed excellent thickening capacity, whereas DD and DE flours exhibited low viscosity and resistance to disintegration induced by heat and shear. DA-W flour exhibits moderate physicochemical properties, rendering it versatile for a multitude of applications. Gelatinization enthalpy (ΔH) ranged from 3.46 J/g to 8.14 J/g, indicating DA-P granular structure had more crystallites while A flour had lower thermostability. All flours exhibited unique characteristics, offering diverse options as texturizing agents for food analog formulation.
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    Cooking of short, medium and long-grain rice in limited and excess water: Effects on microstructural characteristics and gastro-small intestinal starch digestion in vitro
    (Elsevier Ltd, 2021-07) Tamura M; Kumagai C; Kaur L; Ogawa Y; Singh J
    The purpose of present study was to investigate the impact of cooking methods on starch hydrolysis of rice grain using an in vitro digestion model. Three varieties of short, medium and long-grain rice were cooked in two different ways: in limited water method (LWM) using a rice cooker and excess water method (EWM) using a pan. The water absorption of raw rice grain was found to differ among the different rice varieties. The moisture, crude protein, total starch and resistant starch contents of the grain were affected by the cooking method. Starch hydrolysis for medium and long-grain rice at 210 min was higher for rice cooked through LWM (75.1 and 87.5%, respectively) than those cooked using the EWM (65.8 and 64.5%, respectively). Microscopic observations of grain cooked through LWM and EWM showed that the former had bigger voids present throughout the grain and had more cell wall damage than the latter, confirming that the microstructural characteristics were responsible for better enzyme accessibility and higher starch hydrolysis. These results revealed that the starch digestibility of rice grain cooked through different methods was affected by the disruption of the tissue structure that was dependent on the cooking method.
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    Starch digestibility of cooked rice as influenced by the addition of different tea types (Camellia sinensis): An in vitro study
    (Elsevier B.V., 2023-06-26) Apinanthanuwong G; Aumasa T; Ogawa Y; Singh J; Panpipat W; Donlao N
    The stability of tea catechin is influenced by various factors such as tea types, pH and digestive processes. The study aimed to investigate the effect of different tea types on the stability of tea catechin and their impact on starch digestibility and glycemic response to different types of cooked rice. Cooked rices were co-digested with green tea, oolong tea and black tea, and the catechin profiles were correlated with the inhibition of enzymatic digestion. The findings revealed that the green tea exhibited to be the most potent inhibitory effect on starch digestion. In addition, due to its highly porous structure, glutinous rice showed a higher starch hydrolysis rate and glycemic index than jasmine rice. The estimated glycemic index (eGI) of cooked jasmine rice co-digested with green, oolong, and black teas were 61.95 ± 1.07, 64.62 ± 1.12, and 67.14 ± 0.87, respectively, while eGI values of cooked glutinous rice were 77.55 ± 1.15, 79.98 ± 0.98, 81.45 ± 0.75, respectively. The findings indicates that epigallocatechin (EGC) achieves the highest stability. Overall, the results provided compelling evidence that tea types and rice structure affect the regulation of starch digestion and eGI of cooked rice.
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    The role of herbal teas in reducing the starch digestibility of cooked rice (Oryza sativa L.): An in vitro co-digestion study
    (Elsevier GmbH on behalf of Society of Nutrition and Food Science e.V, 2023-11-01) Aumasa T; Ogawa Y; Singh J; Panpipat W; Donlao N
    Herbal teas are well known for their antidiabetic effects due to the abundance of phenolic acids, flavonoids, and tannins. An in vitro co-digestion test was conducted to observe influence of herbal teas (HTs) i.e., beal fruit (BA), mulberry leaf (MB), gymnema leaf (GM), and chrysanthemum flower (CS) on starch digestibility of cooked rice and to elucidate correlation analysis of phytochemicals and their antioxidant activities during in vitro starch hydrolysis (SH). HTs prepared from GM and MB showed highest reduction of SH, kinetic constant and estimated glycemic index (eGI) of cooked rice, followed by BA and CS. Besides, MB and GM teas decreased the eGI of cooked rice up to 15%, followed by BA and CS teas, respectively. Phytochemicals and their antioxidant activities were positively correlated to SH, with both parameters displaying a higher decrease in intestinal phase when compared to gastric phase during in vitro co-digestion. These results indicate a strong interaction among phytochemicals and α-amylase in influencing glycaemic parameters. Thus, HTs has the potential to provide functional health benefits in lowering postprandrial hyperglycemia.