不同阶段中华绒螯蟹脂含量及脂肪酸组成分析

Lipid Content and Fatty Acid Composition of Eriocheir sinensis at Different Stages of Growth

通过索氏抽提法及气相色谱(GC)法对10、11月和12月的中华绒螯蟹体肉及蟹黄、蟹膏的脂含量与脂肪酸组成进行研究。结果表明:中华绒螯蟹雌蟹体肉脂含量呈下降趋势而雄蟹体肉脂含量呈上升趋势;蟹黄、蟹膏脂含量均在10月份达到三节点最高,处于品质最佳时期,其后呈下降趋势。其中,体肉脂含量相对较低,且雌蟹高于雄蟹;蟹黄、蟹膏脂含量相对较高,且蟹膏高于蟹黄。实验共检测出16种脂肪酸,其中饱和脂肪酸(SFA)5种,单不饱和脂肪酸(MUFA)4种,多不饱和脂肪酸(PUFA)7种,以油酸(C18:1ω9)比例最高,不饱和脂肪酸的比例高于饱和脂肪酸。以FAO/WHO推荐的ω3/ω6比例为评价指标,11月份中华绒螯蟹的体肉及蟹黄和10月份的蟹膏对人体健康最有利。以油酸的含量作为营养品质的评价指标,三节点的蟹体肉、蟹黄及蟹膏均具有较好的品质。

The lipid content and fatty acid composition of body meat, crab spawn and crab paste at different growth stages （October, November and December） of E.sinensis were analyzed by Soxhlet extraction method and gas chromatography （GC）. The results showed that the lipid content showed a descending trend in the body meat of female crab but an ascending trend in male crab. The highest lipid content was found in crab spawn and crab paste in October, with the best quality at this growth stage, but descended as the growth proceeded; the lipid content was relatively lower in body meat and indicated a higher level in female crab than in male one, while crab spawn and crab paste contained a higher amount of lipids and the lipid content of crab paste was higher than that of crab spawn. Sixteen fatty acids were detected in E.sinensis including 5 saturated fatty acids （SFA）, 4 monounsaturated fatty acids （MUFA） and 7 polyunsaturated fatty acids （PUFA）. Among these fatty acids, oleic acid （C18：1） was the most abundant and unsaturated fatty acids had a higher proportion than saturated ones. According to the ω3/ω6 ratio recommended by the FAO/ WHO, the crab body meat and crab spawn in November and the crab paste in October were most beneficial to human health. All the body meat, crab spawn and crab paste of E.sinensis at three growth stages had good nutritive quality as indicated by the dominance of oleie acid.