Effects of different diets on the edible quality and flavor-related compounds of Chinese mitten crab ( Eriocheir sinensis )

This study aims to explore the feasibility of trash fish (TF), mealworm (MW), black soldier fly larvae (BSFL), fly maggot (FLM), and golden apple snail meat (GASM) as a diet for Chinese mitten crab ( Eriocheir sinensis ). Five experimental diets (TF, MW, BSFL, FLM and GASM) were fed to crabs with an initial weight of 4.15g for 8 weeks. The results showed that the muscle-free flavor amino acid (FFAA) content in the BSFL and GASM groups was similar to that in the TF group (P > 0.05). The hepatopancreas FFAA content in the GASM group was similar to that in the TF group (P > 0.05). In the GASM group, only muscle 5’-inosinic acid did not reach the same level as the TF group (P < 0.05), while in the MW and BSFL group, only the muscle 5’-adenosine acid and the hepatopancreas 5’-guanosine acid content reached the same level as the TF group, respectively (P > 0.05). The proportion of hepatopancreas n-6 PUFAs in the MW and GASM groups reached the same level as the TF group (P > 0.05), while the proportion of hepatopancreas n-3 PUFAs in all four groups was significantly lower than the TF group (P < 0.05). The proportion of hepatopancreas n-3 PUFAs in the GASM group was significantly higher than that in the BSFL, MW, and FLM groups (P < 0.05). In this experiment, the three insect diets have a significant negative impact on the edible quality and flavor of the crabs. The GASM diet shows little effect on muscle and hepatopancreas FFAAs and nucleotides. The proportion of hepatopancreas n-3 PUFAs in the GASM group was significantly lower to the TF group, but it was still significantly higher than those of the three insect groups. In conclusion, based on the measured biochemical indicators, among the four types of diet on the edible quality and flavor, GASM has the greatest potential to replace TF as the diet for E. sinensi .