怀枝荔枝中游离态和键合态风味物质的检测分析

以怀枝荔枝为研究对象，采用β- 葡萄糖苷酶水解，结合Amberlite XAD-2 树脂吸附和GC-MS 分析技术研究其游离态和键合态香气组成。结果表明，怀枝荔枝中游离态和键合态香气成分在组成和含量上差异较大。怀枝荔枝中游离态香气成分有41 种，含量较高的有苯甲酸、香叶醇、1,2- 苯二羧酸二异辛酯、苯乙醇、棕榈酸甲酯、富马酸二甲酯、苯甲醇等；键合态香气成分有33 种，含量较高的有苯甲酸、香叶醇、山梨酸、苯乙醇、苯甲醇、邻苯二甲酸二丁酯、金合欢醇、香茅醇等。其中有15 种物质包括1- 十一醇、1- 己醇、2- 庚醇、3- 辛醇、β- 月桂烯、苯甲醛等在游离态组分中并不存在，且荔枝中典型香气成分包括香叶醇、苯甲醇、苯乙醇、香茅醇等在含量上键合态都比游离态多。

Free and Glycosidically Bound Volatile Flavor Compounds in Fruit of Litchi chinensis Huaizhi

Free and glycosidically-bound volatile compounds were isolated and identified from Huaizhi litchi juice using an Amberlite XAD-2 column and GC-MS. The volatile compounds from the bound fraction were released by hydrolysis with almond β-glucosidase. The results indicated that the differences of aromatic constituents in composition and content between free and bound fraction were significant. Totally 41 and 33 compounds were identified in free and bound fraction, respectively. In the free fraction, the major volatile compounds found were benzenecarboxylic acid, geraniol, 1,2-benzenedicarboxylic acid diisooctyl ester, phenylethyl alcohol, hexadecanoic acid methyl ester, (E)-2-butenedioic acid dimethyl ester , benzyl alcohol, etc. However, in the bound fraction, the latent major volatile compounds found were benzenecarboxylic acid, geraniol, sorbic acid, phenylethyl alcohol, penzyl alcohol, dibutyl phthalate, farnesol, citronellol, etc. In addition, there were 15 compounds that just existed as glycosides, such as 1-undecanol, 1-hexanol, 2-heptanol, 3-octanol, beta-myrcene, benzaldehyde, etc. Especially the contents of typical aroma in litchi such as geraniol, benzyl alcohol, phenylethyl alcohol and citronellol were higher than those in free fraction.