Widely Targeted Metabolomics Investigation of the Meat Taste of Eriocheir Sinensis Under Ammonia Exposure

Ammonia-N may accumulate in the aquaculture water of Eriocheir sinensis. This study investigated the effects of ammonia (0, 10.47, and 41.87 mg/L) on the meat taste of E. sinensis. Electronic tongue analysis showed that the low-concentration ammonia group had the highest umami score and the lowest bitterness score. Metabolomics combined with quantitative analysis showed that ammonia increased the 5′-inosine monophosphate content and the equivalent umami concentration and reduced the arginine content, thereby enhancing the umami and reducing the bitterness of crab meat. Exposure to high concentrations of ammonia reduced umami amino acids (glutamic acid and aspartate) and increased bitter amino acids (leucine, isoleucine, and tryptophan), which hindered the taste development of crab meat. The increased sweetness amino acids (glutamine and serine) in the high-concentration ammonia group may be key ammonia detoxification products. This study reveals that phospholipids and small peptides may participate in improving the flavor of crab meat under ammonia exposure.