Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, PR China.
Food Chem. 2017 Apr 15;221:636-643. doi: 10.1016/j.foodchem.2016.11.126. Epub 2016 Nov 23.
In this study, rice bran was successively steamed with α-amylase, fermented with lactic acid bacteria, and hydrolyzed with complex enzymes. The changes in phenolic profiles and antioxidant activities of the corresponding aqueous solutions from three stages were investigated. Compared to the first stage, fermentation and complex enzyme hydrolysis significantly increased the total phenolics, total flavonoids, total FRAP and ORAC values by 59.2%, 56.6%, 73.6% and 45.4%, respectively. Twelve individual phenolics present in free or soluble conjugate forms were also analyzed during the processing. Ferulic acid was released in the highest amount among different phenolics followed by protocatechuic acid. Moreover, a major proportion of phenolics existed as soluble conjugates. The results showed that fermentation and complex enzyme hydrolysis enhanced total phenolics and antioxidant activities of aqueous solution from rice bran pretreated by steaming with α-amylase. This research could provide basis for the processing of rice bran beverage rich in phenolics.
本研究采用α-淀粉酶对米糠进行分步蒸煮，然后用乳酸菌进行发酵，再用复合酶进行水解。考察了这三个阶段相应水溶液中酚类物质组成和抗氧化活性的变化。与第一阶段相比，发酵和复合酶水解使总酚、总黄酮、总 FRAP 和 ORAC 值分别显著增加了 59.2%、56.6%、73.6%和 45.4%。在加工过程中还分析了以游离或可溶共轭形式存在的 12 种个体酚类物质。不同酚类物质中，阿魏酸的释放量最高，其次是原儿茶酸。此外，很大一部分酚类物质以可溶共轭物的形式存在。结果表明，发酵和复合酶水解提高了经α-淀粉酶分步蒸煮预处理的米糠水溶液中的总酚和抗氧化活性。该研究可为富含酚类物质的米糠饮料的加工提供依据。
