凡纳滨对虾虾肉和虾头中风味物质的比较

摘要

为充分利用和开发虾头资源从而提高对虾经济附加值,同时探讨熟制对虾类风味产生的影响,以凡纳滨对虾生、熟虾肉和生、熟虾头为研究对象,利用氨基酸自动分析仪、高效液相色谱法(HPLC)和气相色谱—质谱联用法(GC/MS)分别对氨基酸、呈味核苷酸、挥发性物质和营养成分的含量进行检测.结果显示,虾头中的蛋白质含量显著高于虾肉,熟制会使粗蛋白的含量下降,但变化差异不显著;虾头中必需氨基酸(EAA)含量和游离氨基酸总量(TFAA)显著高于虾肉,二者主要游离氨基酸种类相同(甘氨酸、精氨酸、脯氨酸、丙氨酸和苏氨酸),对虾头呈味有贡献的游离氨基酸种类更丰富;虾头和虾肉中肌苷酸(IMP)含量最高,腺苷酸(AMP)次之,二者的味道强度值(TAV)均大于1,对鲜味贡献较大.GC/MS共检测出88种挥发性物质,虾肉和虾头中分别特有29种和18种,挥发性物质种类和含量的差异形成虾肉和虾头的特殊气味,熟制产生大量的醛类、酮类和芳香类物质.研究表明,凡纳滨对虾虾肉和虾头中营养物质、游离氨基酸、呈味核苷酸、挥发性物质的组成和含量对风味的贡献存在显著差异.%In order to make full use of Litopenaeus vannamei's shrimp head,increase the economic value and discuss the influence of cooking on the flavor, the shirimp meat and heads were detected for amino acids, flavor nucleotides, volatile flavor compounds and the nutrients by the method of amino acid analyzer, high performance liquid chromatography (HPLC) and gas chromatography-mass spectrography (GC/MS). The results showed that the protein content of head was significantly higher than that of meat, while the crude protein content decreased in cooked shrimp, but the difference was not significant. The contents of essential amino acid (EAA) and total free amino acid (TFAA) in head were significantly higher than those in meat and the main free amino acids were same (glycine, arginine, proline, alanine, threonine), and amino acids that contribute to flavor were more abundant in head; IMP had the highest content in meat and head, AMP took second place, and the taste activity values (TAV) of them were more than 1, which made a great contribution to umami flavor. Totally 88 volatile compounds were identified by GC/MS and compared for significant differences, the numbers of unique compounds in meat and head were 29 and 18 respectively. The differences of kinds and quantity led to special smell, and cooking produced mass aldehyde, ketone and aromatic compounds. Preliminary results showed that significant differences in the composition and content of amino acids, flavor nucleotides, volatile flavor compounds and nutrients observed between meat and head lead to different flavors.