Division of Science of Biological Resources, United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
Co-operative Academic Institute (CAI), Faculty of Economics, Kasetsart University, Bangkok 10900, Thailand.
Food Chem. 2020 Nov 1;329:127157. doi: 10.1016/j.foodchem.2020.127157. Epub 2020 May 30.
The processing and digestive stability of ethanolic extracts from four Thai rice bran varieties, namely Khao Dawk Mali 105, Hom Nil, Kiaw Ngu, and Leum Pua, were assessed by applying different thermal and pH conditions, as well as in vitro gastrointestinal digestion models. High-performance liquid chromatography, Folin-Ciocalteu analysis, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays were used to determine the chemical composition, total phenolic content (TPC), and antioxidant activity. Thermal treatment at 100 °C for 15 min induced the degradation of phenolic components and TPC, whereas the antioxidant activities measured by DPPH and FRAP assays remained stable after the heat treatment. Higher phenolic content and antioxidant activity values were observed in the extracts incubated at acidic pH levels of 3 and 5. After simulated digestion, all extracts exhibited the decrease of phenolic compounds and anthocyanin contents, as well as antioxidant activities.
采用不同的热和 pH 条件以及体外胃肠消化模型，评估了四种泰国米糠品种（Khao Dawk Mali 105、Hom Nil、Kiaw Ngu 和 Leum Pua）的乙醇提取物的加工和消化稳定性。高效液相色谱法、福林-考尔法分析以及 2,2-二苯基-1-苦基肼（DPPH）自由基清除活性和铁还原抗氧化能力（FRAP）测定用于测定化学成分、总酚含量（TPC）和抗氧化活性。在 100°C 下热处理 15 分钟会导致酚类成分和 TPC 的降解，而 DPPH 和 FRAP 测定法测量的抗氧化活性在热处理后保持稳定。在酸性 pH 值为 3 和 5 的条件下孵育时，提取物中观察到更高的酚类含量和抗氧化活性值。模拟消化后，所有提取物的酚类化合物和花青素含量以及抗氧化活性均降低。
