稻米中的蛋白质分布与营养分析

DISTRIBUTION AND NUTRITIONAL ANALYSIS OF RICE PROTEINS

综述了稻米蛋白质的分布 ,氨基酸的组成以及二者的相关性 ,并对稻米蛋白质的营养价值进行了分析。蛋白质在稻米中的分布不是均匀的 ,而是表现为由外至内总蛋白质的百分含量逐渐降低。其氨基酸的组成特点为 :疏水性氨基酸 (40 .lmol% ) >酸性氨基酸 (2 6 .0mol% ) >无电荷极性氨基酸 (2 1.8mol% ) >碱性氨基酸 (12 .2mol% )。蛋白质含量同赖氨酸 (Lys)含量呈负相关 ,同酪氨酸 (Tyr)、苯丙氨酸 (Phe)呈正相关。稻米蛋白质是一种优质蛋白质 ,米粒外层蛋白质的营养价值最高 ,中层次之 ,粒心又略有增高。

DISTRIBUTION OF RICE PROTEIN,AMINO ACID COMPOSITION AND THEIR CORRELATION ARE REVIEWED.MOREOVER,THE NUTRITIVE VALUE OF RICE PROTEIN WAS ANALYZED.THE DISTRIBUTION OF PROTEIN IN RICE KERNEL WAS NOT EVEN,WITH DECLINING PERCENTAGE CONTENT FROM OUTER LAYER TO INNER LAYER.THE CHARACTERISTICS OF AMINO ACID COMPOSITION ARE AS FOLLOWS:HYDROPHOBIC(40.1MOL%)>ACIDIC(26.0MOL%)>UNCHARGED POLAR(21.8MOL%)>BASIC(12.2MOL%).AS REGARDS CORRELATION BETWEEN PROTEIN LEVEL AND AMINO ACIDS,LYS SHOWED A SIGNIFICANTLY NEGATIVE CORRELATION COEFFICIEN,WHEREAS PHE AND TYR HAD SIGNIFICANTLY POSITIVE CORRELATION COEFFICIEN.RICE PROTEIN IS OF HIGH NUTRITIONAL GUALITY THE NUTRITIVE VALUE OF RICE PROTEIN VARIED IN DIFFERENT LAYERS,I.E.,HIGH IN THE OUTER LAYER,LOW IN THE MIDDLE LAYER,AND SLIGHTLY HIGHER IN THE CENTER OF RICE KERNEL.