Characteristic Quality of Chinese Mitten Crabs from Different Lakes in Jiangsu Province

This study selected Chinese mitten crab samples from Yangcheng Lake, Hongze Lake, Gaoyou Lake and Changdang Lake in Jiangsu province. Traditional detection methods and multi-omics techniques were employed to systematically analyze the lake-specific characteristics of their basic nutritional components, fatty acids, amino acids, stable isotopes, lipidomics and metabolomics. The results indicated that there were significant differences in the quality of crabs from different lakes. In terms of fatty acid composition, the content of ω-3 polyunsaturated fatty acids was significantly higher in Yangcheng Lake crabs than in those from the other lakes. The linoleic acid content was 2–3-fold higher in Changdang Lake crabs than in those from the other lakes. Amino acid composition analysis revealed that the total and essential amino acid contents in the meat of crabs from Changdang Lake was significantly higher than those from Hongze and Gaoyou Lakes. Stable isotope analysis further revealed significant differences in the δ¹³C of crab shells among the different lakes, making this an important indicator for the geographic origin traceability of crabs. Lipidomics analysis showed significant differences in the lipid composition between male and female crabs, with 244 differential lipids identified in male crab meat and 260 in female crab meat. These lipids, mainly consisting of sphingolipids, glycerolipids, and glycerophospholipids, could help in geographical origin identification. Metabolomics analysis also demonstrated that crabs from different lakes could be distinguished by their differential metabolites. A total of 13 classes of differential metabolites were identified, including 20 free amino acids, 14 organic acids, 7 alcohols, 7 aldehydes, and 6 fatty acids. In conclusion, this study provides a scientific basis for the quality evaluation, geographical origin tracing, and high-quality industrial development of Chinese mitten crab.