为了评价四川小麦地方品种籽粒蛋白质的营养价值,本文通过化学分析法研究了67个四川小麦地方品种的蛋白质和氨基酸含量及其组成特性。结果表明:蛋白质含量平均为11.86%;18种氨基酸中谷氨酸、脯氨酸、亮氨酸和天门冬氨酸含量丰富,而色氨酸、蛋氨酸和半胱氨酸含量较少;必需氨基酸和总氨基酸含量分别为3.65%和11.68%;必需氨基酸含量与氨基酸总量之比为31.25%;必需氨基酸含量与蛋白质总量之比为30.78%;氨基酸评分表明,赖氨酸和蛋氨酸+半胱氨酸的氨基酸评分平均值最低分别为47和70,因此赖氨酸和蛋氨酸+半胱氨酸分别为第1和第2限制性氨基酸;必需氨基酸指数平均值为60。67个小麦地方品种中7个品种其赖氨酸含量相对较高,赖氨酸的氨基酸评分都在60以上;11个品种的必需氨基酸指数较高、均大于65,具有较为平衡的氨基酸组成;13个品种的必需氨基酸含量与氨基酸总量之比超过36%。是蛋白较为优质的小麦品种。结论:与WHO模式比较,四川小麦地方品种中存在部分优质营养品质资源。
To evaluate the nutritional value of protein for 67 Sichuan local wheat cuhivars, the protein content and amino acid composition were studied by chemical and HPLC analysis. The results show: The average protein content of the 67 Sichuan wheat cuhivars is 11.86%. Among the 18 detected amino acids, the contents of Glu, Pro, Leu and Asp are relatively high, whereas the contents of Trp, Met and Cys are relatively low. The contents of essential amino acids and total amino acids are 3.65% and 11.68% , respectively, and the ratio of essential amino acids to total amino acids is 31.25%. The ratio of essential amino acids to total protein is 30.78%. The average amino acid scores of Lys and Met are the lowest, 40% and 70 respectively, indicating that Lys and Met are the first and second limiting amino acids, respectively. The average of essential amino acid indexes is 60. Among the 67 Sichuan wheat cultivars, the contents of Lys in 7 wheat cultivars are relatively high with the essential amino acid scores of Lys above 60 ; the essential amino acid indexes of 11 wheat cultivars are above 65, indicating a rather balanceable composition of amino acids. Thirteen wheat cultivars are detected to be of good protein quality, and their ratios of essential amino acids to total amino acids are above 36%. Conclusion: compared with FAO/WHO pattern, a part of the 67 Sichuan wheat cultivars are of good nutrition quality.