Comparison of non-volatile compounds and sensory characteristics of Chinese mitten crabs (Eriocheir sinensis) reared in lakes and ponds: Potential environmental factors

To reveal the impact of culture condition on the quality of Chinese mitten crabs (Eriocheir sinensis), a study was conducted comparing pond-produced crabs and lake-produced crabs in terms of non-volatile compounds and sensory characteristics, and potential environmental factors were analyzed concurrently. Both groups of crabs were cultured in a similar way, with submerged macrophytes flourishing during most of the cycle. The results showed that the concentrations of total free amino acids (FAAs), umami 5'-nucleotide compounds and poly-unsaturated fatty acids in the hepatopancreas and muscle of pond-produced crab were significantly lower than those of lake-produced crabs. The carotenoid concentrations in the shell and hepatopancreas of pond-produced crabs were significantly lower than those of lake-produced crabs. Significant differences were also observed in terms of shell color, hepatopancreas color and the taste of and preference for the hepatopancreas through sensory evaluation. However, no difference was detected in the taste of muscle. No unpleasant odors or tastes were detected in the muscle or hepatopancreas in either group of crabs. A significantly lower concentration of chlorophyll-. a, higher DO and pH values, and poorer biodiversity of microalgae were observed in the pond water compared with lake water; however, no difference in the concentrations of total nitrogen and total phosphorus were detected. It is speculated that the low biodiversity of microalgae and flourishing macrophytes in the ponds contributed directly or indirectly to the faint color as well as the flavor of Chinese mitten crab.