不同品种荔枝果实游离氨基酸分析

为探明荔枝果实中游离氨基酸组成及含量，采用AccQ ·Tag柱前衍生反相高效液相色谱法测定紫娘喜、大丁香、黑叶、兰竹和甜眼荔枝果实中的17种游离氨基酸含量。结果表明：测定方法重现性好，精密度高；甜眼果实中的人体必需氨基酸含量占氨基酸总量的36.4%，人体必需氨基酸含量与非必需氨基酸含量之比为0.57，较接近理想蛋白质的标准要求；紫娘喜、大丁香、黑叶、兰竹和甜眼荔枝果实均含有丰富的药效氨基酸、鲜味氨基酸、甜味氨基酸以及少量的芳香族氨基酸，但不同品种间的含量及比例差异较大。因此，不同荔枝品种的口感和风味明显不同。

Analysis of Free Amino Acids in Litchi Fruits from Different Cultivars

An AccQ ·tag precolumn derivatization and reversed phase HPLC method was presented to determine the contents of 17 free amino acids in litchi fruits from 5 different cultivars, Ziniangxi, Dadingxiang, Heiye, Lanzhu and Tianyan. The method proved highly reproducible and precise. The ratio of essential amino acids to total amino acids was 36.4% and to non-essential amino acids 0.57 in Tianyan, indicating good agreement with the ideal human protein requirements. The five litchi cultivars were all rich in medicinal, umami and sweet amino acids with a difference in their contents and small amounts of several aromatic amino acids were also found. Therefore, different litchi cultivars distinctly differ in taste and flavor.