黑米皮的营养与抗氧化评价及其加工处理的保质效果

Nutrients and antioxidation of black rice pericarp and the preservation effects of processing techniques

分析了黑米皮的主要营养成分、活性物质含量及总抗氧化能力,比较了热烘烤、微波加热和挤压膨化处理等加工工艺对黑米皮活性物质和总抗氧化能力的影响。结果表明,黑米皮的总黄酮、总花色苷及总抗氧化能力明显高于精米的,占黑米重12%的黑米皮的总黄酮、总花色苷和总抗氧化能力均占到整粒黑米的98%以上。黑米皮含有丰富的蛋白质、脂肪、粗纤维、维生素和矿物质等营养成分,氨基酸种类齐全,结构合理,必需氨基酸和不饱和脂肪酸比例均较高,可视为黑米营养成分和活性物质的主要载体。热烘烤、微波加热和挤压膨化3种加工方法对黑米皮总黄酮、总花色苷及总抗氧化能力的影响不尽相同,其中,挤压膨化处理的影响较小,微波处理的其次,热烘烤处理的影响较大。经挤压膨化处理后黑米皮的过氧化值和酸价变化较平缓,保质效果稳定,可作为黑米皮保藏的首选工艺。

The nutrients and antioxidation of black rice pericarp and the effects of processing techniques such as firing, microwave heating and extrusion techniques were studied. The results are as follows: the nutrients and antioxidation of the pericarp are significantly superior to those of milled rice of black rice. The total antioxidant capacity (TAC), total flavonoid and anthocyanin contents of the pericarp, which is only 12% in weight, account for over 98% of whole black rice grain, respectively. Black rice pericarp is rich in protein, fat, crude fiber, vitamins and mineral elements and is considered as the main carrier for nutrients and active substances of black rice, featuring complete and balanced amino acids and high percentages of essential amino acids and unsaturated fatty acids. The processing techniques such as firing, microwave heating and extrusion have different effects on the TAC, total flavonoid and anthocyanin contents of black rice pericarp, among them extrusion has the least effect, followed by microwave heating and firing. Extrusion is the best processing technique for preservation of black rice pericarp because it can achieve stabilizing effects on peroxide value(POV) and acid value(AV).