中华绒螯蟹性腺加热熟制前后挥发性成分和脂肪酸组成分析

对中华绒螯蟹生/熟性腺中的挥发性成分进行了分离鉴定;同时测定了生鲜和熟制性腺中的脂肪酸组成。结果表明,所测四个样品中共检查出62种物质,对这些物质进行显著性差异分析和气味活性值计算后发现,雌/雄蟹性腺中的挥发性物质存在显著性差异,且在由生变熟的过程中,有大量的醛类、呋喃类、含氮类化合物、含硫类化合物产生,其中变化最为明显的为:3-甲基丁醛、2-甲基丁醛、辛醛、2-戊基呋喃、二甲基二硫化物等物质,这些物质通常具有较高的气味活性值(OAV值),对香气贡献较大。我们推断这些化合物可能是加热过程中由风味前提物质反应分解生成。中华绒螯蟹性腺脂肪酸中不饱和脂肪酸(UFA)高达75%左右,且在由生变熟的过程中,与风味相关性较大的油酸、亚油酸、亚麻酸等变化明显,变化趋势与挥发性物质的变化呈现正相关性,说明脂质是产生蟹性腺风味的重要前体物质。

Analysis of Volatile Components and Fatty Acids Derived from Eriocheir sinensis Gonad before and after Cooking

The volatile flavor compositions of Chinese mitten crab (Eriocheir sinensis) gonads were trapped by a new material (Mono Trap) and analyzed by gas chromatography-mass spectrometry (GC-MS); meanwhile, the fatty acids in raw and cooked gonads were also studied. A total of 62 volatile compounds were identified by GC-MS. Male/female gonads existed significant difference. A large number of aldehydes, furans, nitrogen-containing, sulfur-containing compounds were produced in cooking process, especially 3-methylbutanal, 2-methylbutanal, octanal, 2-pentylfuran, dimethyl disulfide, which also had high OAVs and played an important role in gonads aroma. It was inferred that these compounds were produced by the decomposition of the aromatic precursors. Unsaturated fatty acids (UFA) in raw/cooked Chinese mitten crab gonad was as high as 75%. Besides, the contents of flavor related acids (e.g.: oleic acid, linoleic acid and linolenic acid) changed remarkably, and positively correlated with the changes of volatile compounds during cooking. Therefore, lipid was the important aromatic precursor of Chinese mitten crab gonad.