Min Byungrok, McClung Anna, Chen Ming-Hsuan
Food Science and Technology Program, Department of Agriculture, Food, and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA.
Dale Bumpers National Rice Research Center, Agricultural Research Service, United States Department of Agriculture, 2890 Hwy 130 E., Stuttgart, AR 72160, USA.
Food Chem. 2014 Sep 15;159:106-15. doi: 10.1016/j.foodchem.2014.02.164. Epub 2014 Mar 12.
The impacts of parboiling and wet-cooking, alone and in combination, on the concentrations of lipophilic antioxidants (vitamin E and γ-oryzanol), soluble (including proanthocyanidins and anthocyanins) and cell wall-bound phenolics, and antioxidant capacities in whole grain rice from six cultivars having different bran colours were investigated. Parboiling rough and brown rice increased the concentrations of lipophilic antioxidants in whole grain rice but decreased the concentrations of total phenolics and antioxidant capacities found in the soluble fraction. After hydrothermal processing of purple bran rice, the retention of extractable anthocyanins was low, but was high for simple phenolics. For proanthocyanidins found in red bran rice, the extractable oligomers with a degree of polymerization (DP) less than 4, increased up to 6-fold; while for oligomers with DP⩾4 and polymers, there was a significant decrease that was positively correlated with the DP and the temperature of the processing methods. The presence of hulls helped to retain water-soluble antioxidants during parboiling.
研究了单独或联合采用预煮和湿煮对六个具有不同麸皮颜色的全谷物水稻品种中亲脂性抗氧化剂（维生素E和γ-谷维素）、可溶性酚类（包括原花青素和花青素）以及细胞壁结合酚类的浓度，以及抗氧化能力的影响。预煮糙米和糙米粉增加了全谷物水稻中亲脂性抗氧化剂的浓度，但降低了可溶性部分中总酚类的浓度和抗氧化能力。对紫麸皮水稻进行水热处理后，可提取花青素的保留率较低，但简单酚类的保留率较高。对于红麸皮水稻中的原花青素，聚合度（DP）小于4的可提取低聚物增加了6倍；而对于DP⩾4的低聚物和聚合物，则有显著下降，且与DP和加工方法的温度呈正相关。谷壳的存在有助于在预煮过程中保留水溶性抗氧化剂。
