越冬暂养对雌性中华绒螯蟹的营养品质及风味的影响

为探究越冬暂养后雌性中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)是否存在营养流失或风味品质下降现象，该研究利用嵌入在池塘循环水养殖系统中的网箱对雌性河蟹进行105天暂养，分析了暂养前后河蟹一般生物学指数、营养成分、脂肪酸、游离氨基酸、呈味核苷酸及挥发性风味物质的变化差异。结果显示，河蟹在越冬暂养期间处于稳定的生长状态，未出现“掉膏”。暂养后的河蟹，肌肉中必需氨基酸含量(E)显著上升(P<0.05)，必需氨基酸与游离氨基酸总含量比值(E/T)显著上升(P<0.05)；可食组织中腺苷酸(AMP)和肌苷酸(IMP)显著增加(P<0.05)，次黄嘌呤(Hx)和肌苷(HxR)显著下降(P<0.05)；虽然可食组织及卵巢中粗脂肪、C22:1和C22:4含量显著下降，但C20:2、C20：4和C20：5等多不饱和脂肪酸含量显著升高(P<0.05)，同时PUFA/SFA比值显著上升；河蟹暂养105天后，1-辛烯-3-醇，己醛，壬醛和2-戊基呋喃为主要的挥发性物质，这些具有良好气味的物质占主导地位，表明河蟹的风味整体优于暂养前。以上结果表明，越冬暂养后河蟹的营养有一定的流失，品质和食用风味有所改善。

Effects of overwintering cultivation on nutritional quality and flavor of female Eriocheir sinensis

In order to investigate whether there are any losses in nutrition or a decrease in flavor and quality of female E. sinensis after overwintering, we reared female E. sinensis for 105 days in 3 cages embedded in a pond recirculating aquaculture system. By comparing the general nutrition indices, proximate composition, fatty acids, free amino acids, nucleotides and volatile flavors of E. sinensis before and after overwintering cultivation, we found there was no weight loss in the total edible tissues and that E. sinensis was in stable growth during the overwintering cultivation. Interestingly, we found that after 105 days of overwintering cultivation, the total content of free amino acids decreased(P<0.05), while the ratio of essential amino acids to free amino acidsincreased significantly(P<0.05), and the ratio of non-essential amino acids to free amino acids decreased significantly(P<0.05), the ratio of essential amino acids to non-essential amino acids increased significantly(P<0.05). After overwintering cultivation, moreover, adenosine (AMP) and inosinic acid increased significantly(P<0.05), while hypoxanthine and inosine decreased significantly(P<0.05), Although crude fat, C22:1 and C22:4 contents in edible tissues and ovaries were significantly decreased, polyunsaturated fatty acids, such as C20:2(eicosadienoic acid),C20:4(arachidonic acid)and C20:5(eicosapentaenoic acid), were significantly increased(P<0.05), Meanwhile, the PUFA/SFA ratio increased significantly, This indicates that although the nutrition of E. sinensis has been lost to a certain extent after overwintering cultivation, its quality and edible flavor have been improved to some extent. After overwintering cultivation, main volatile substances in edible tissues were 1-octene-3-ol, furfural, hexanal and 2-pentylfuran, indicating a relatively good volatile flavor. The above results indicated that the nutrition of E. sinensis will be lost to a certain extent after overwintering cultivation, and the quality and Edible flavor have been improved. Our results provide a reference standard for the overwintering cultivation of E. sinensis.