Study On Nutrition And Flavor Components Of Mature Females Cultured And Wild Mud Crabs In Hainan

The mud crab (Scylla paramamosain) aquaculture is developing fast worldwide, and there is a high consumer demand for MC in China, where such crabs especially the gravid female, are regarded as a delicacy. In Hainan Island, pond-rearing wild MC juveniles fed with local trash fish and shrimps in brackish water has been proved a practical aquaculture model. The wild MC annual output has been declining in Hainan due to overfishing, as aquaculture technology with MC does not improve, the yield and quality were not significantly improved in recent years, Often the high quality MC is hard to find in the market. However, the nutritional and flavor components of cultured and wild mature females MC has not been evaluated.Initially, nutrients of three kinds of sea crabs were analyzed. The cultured MCs had higher ratio of total edible yield than the wild ones. However, the contents of crude protein and crude lipid in the cultured MCs were significantly lower than in the wild MCs, while the water and ash contents were much higher in the cultured MCs, which probably were ascribed to the difference of growing environment in salinity. Although the contents of total essential amino acids (EAA) in gonad and claw muscle of wild MC were significantly higher, the contents of most EAAs (6 EAAs in gonad, 5 EAAs in claw muscle and 5 EAAs in body muscle) of both MC groups had no significant differences. Moreover, there were no significant differences in the contents of poly-unsaturated fatty acids (PUFA), n-3 fatty acids and n-6 fatty acids in gonad of both MC groups, while the contents of total saturated fatty acids (SFA) and mono-unsaturated fatty acids (MUFA) were significantly different between the wild and the cultured MCs. Further, there were no significantly differences in the contents of SFA, MUFA and PUFA in both claw and body muscle between the wild and cultured MCs. In conclusion, the cultured MCs had more or less the same as the wild ones in biochemical compositions of its edible parts, thus were as nutritious as the wild ones.Secondly, non-volatile flavor substances of two kinds of MC were studied and their taste impacts were evaluated by taste active value(TAV). Results show that the arginine,alanine, glycine, proline, glutamic acid, lysine, histidine, methionine and valine are the main free amino acids of two kinds of MC. The highest taste nucleotide of muscles and gonad of two kinds of MC are IMP, followed by AMP, GMP is in the end. Glycine betaine,oxidation thrimethylamine had important contribution to taste of two kinds of MC. The malic acid, citric acid and succinic acid was detected in mus cle tissue of two kinds of MC,The lactic acid, citric acid and succinic acid was detected in muscle tissue of two kinds of MC. According to the TAV can draw succinic acid is the characteristic organic acid of MC.Possible the reason of the MC test unlike any other sea crabs is variety of organic acid...