陕西省不同品种的荞麦氨基酸组成成分分析及营养评价

目的 对陕西省9个代表性品种的荞麦进行氨基酸组成成分分析,比较不同品种荞麦的氨基酸组成,并做出营养评价,为荞麦的合理膳食提供选择依据。方法 选取陕西地区9种代表性荞麦品种,研磨成粉,运用全自动氨基酸分析仪对荞麦全粉的氨基酸成分进行检测分析,采用模糊识别法、氨基酸评分(amino acid score, AAS)法、化学评分(chemistry score, CS)法及氨基酸比值系数(ratio coefficient of amino acid, RCAA)法从不同角度对不同品种的荞麦进行蛋白质营养价值的评价。结果 9个品种的荞麦样品中均检出18种氨基酸,氨基酸总量(total amino acids, TAA)介于9.237 g/100 g-16.287 g/100 g之间,必需氨基酸/氨基酸总量(essential amino acids/total amino acids, EAA/TAA)的值在0.348-0.375之间,各品种的功能性氨基酸和呈味氨基酸含量均有差异,色氨酸含量为28.197 mg/g-44.521 mg/g,高于全蛋蛋白模式(17 mg/g)。9个品种的第一限制氨基酸均为蛋氨酸+胱氨酸,苯丙氨酸+酪氨酸的RCAA为0.867-1.099,与模式值偏离程度最小;赖氨酸次之,为0.751-0.914。西农1513的EAA含量(5.691 g/100 g)、蛋白贴近度(0.891)、氨基酸比值系数分(score of RCAA,SRCAA)(48.083)均为最高,8种EAA的组成最均衡。灰苦荞的必需氨基酸指数(essential amino acid index, EAAI)值(0.891)最高,为良好蛋白源。温沙的AAS(92.840)和CS(57.007)评分最高。结论 9种荞麦氨基酸种类齐全,氨基酸组成及其蛋白质营养价值存在差异,可根据不同营养需求进行合理开发。苯丙氨酸+酪氨酸、赖氨酸和色氨酸含量丰富,与富含蛋氨酸和胱氨酸的食物结合食用,可有效提高荞麦蛋白质的生物利用率。综合多种评价方式,西农1513、灰苦荞和温沙为最具推广价值的3个品种。

Amino acid composition and nutritional value evaluation of different buckwheat varieties in Shaanxi Province

Objective To analyze the amino acid composition of nine representative buckwheat varieties in Shaanxi Province, to compare the amino acid composition of different buckwheat varieties and make a nutritional evaluation, and to provide a basis for reasonable diet selection of buckwheat. Methods Nine representative buckwheat varieties in Shaanxi Province were selected and grinded into flour. The content of amino acids in the buckwheat flour was detected and analyzed by automatic amino acid analyzer. The nutritional values of proteins of different buckwheat varieties were evaluated by Fuzzy distinguish method, amino acid score (AAS) method, chemistry score (CS) method and ratio coefficient of amino acid (RCAA) method. Results Eighteen kinds of amino acids were detected in 9 varieties of buckwheat flour. The total amount of amino acids (TAA) ranged from 9.237 g/100 g to 16.287 g/100 g, and the value of essential amino acids/total amino acids (EAA/TAA) from 0.348 to 0.375. The contents of functional amino acids and flavorful amino acids were dissimilar among the different varieties. The content of tryptophan was 28.197 mg/g-44.521 mg/g, which was higher than that of whole egg protein (17 mg/g). The first limiting amino acid in the nine varieties of buckwheat was methionine+cystine, and RCAA of phenylalanine+tyrosine ranged from 0.867 to 1.099, which was the least deviation from the model value, followed by lysine, with a range of 0.751-0.914. The content of EAA (5.691 g/100 g), fuzzy degree of nearness (0.891) and score of RCAA (48.083) of Xinong 1513 were the highest, and the composition of 8 varieties of EAA was optimum balance. The essential amino acid index (EAAI) value of Tartary buckwheat was the highest (0.891), which was a good protein source. Wensha had the highest AAS (92.840) and CS (57.007) scores. Conclusion The nine buckwheat varieties have a complete amino acid profile, but there are differences in amino acid composition and protein nutritional value, which can be rationally developed according to different nutritional requirements. They are rich in phenylalanine+tyrosine, lysine and tryptophan. It can effectively improve the bioavailability of buckwheat protein by combining with foods rich in methionine and cystine. All the evaluation methods show that Xinong 1513, Tartary buckwheat and Wensha are the three varieties with the most popularization value.