不同品种海棠叶茶游离氨基酸组成分析与评价

Analysis and evaluation of free amino acid in different cultivars of crabapple leaf tea

为了探究不同海棠品种叶片的茶用开发价值,以15个海棠品种嫩芽制成的海棠叶茶为材料,利用全自动氨基酸分析仪对海棠叶茶游离氨基酸的含量和种类进行检测。通过味道活性值(taste active value,TAV)、氨基酸评分(amino acid score,AAS)和必需氨基酸指数(essential amino acid index,EAAI)对氨基酸进行呈味分析和营养评价。结果表明:15个海棠品种叶茶均含有17种氨基酸,游离氨基酸的总量为655.12~3059.69 mg/100 g,必需氨基酸占氨基酸总量的8.49%~37.53%,药用氨基酸含量占氨基酸总量的25.87%~58.14%;基于氨基酸评分,海棠叶茶的第一限制性氨基酸为蛋氨酸和半胱氨酸,必需氨基酸指数最平衡的品种为‘黛玉’、‘完美紫’和‘丰盛’;通过味道活性值的比较,谷氨酸和丝氨酸对呈味贡献最大;利用主成分分析,从氨基酸角度较好地反映出不同海棠品种之间的差异性。该研究为海棠叶茶营养价值及其叶片资源的有效利用提供了参考和依据。

To explore the value of crabapple leave,the free amino acids in crabapple leaf tea made from the buds of 15 crabapple cultivars,were detected by automatic amino acid analyzer.The taste activity value,amino acid score and essential amino acid index were used for the evaluation.The results showed that there were 17 amino acids that could be detected in the leaves of 15 crabapple cultivars,including the total amount of free amino acids 655.12-3059.69 mg/100 g.Moreover,the essential amino acids and the medicinal amino acids account for 8.49%-37.53%and 25.87%-58.14%of the total amino acids,respectively.Based on the amino acid score,the top two limiting amino acids of crabapple leaf tea were Met and Cys,and the most balanced essential amino acid index were M.‘Black Jade’,M.‘Purple prince’and M.“Profussion”.Glu and Ser contribute most to the flavor compared with taste active value.The principal component analysis revealed the differences of different crabapple cultivars.This study provides reference and basis for the nutritional value of crabapple leaf tea and its effective utilization of leaf resources.