Effects of effective microorganisms on the growth performance, nutritional composition and flavour quality of the pond‐culturedEriocheir sinensis

Abstract

The Chinese mitten crab, Eriocheir sinensis (H. Milne Edwards), is an important economic and widely cultivated aquaculture species in China. Under the requirements of health aquaculture, effective microorganisms (EM) have been widely introduced in E. sinensis culture. To date, however, we know little about the influence of EM on E. sinensis, especially in aspects of nutritional composition and flavour quality. Aiming to assess the comprehensive effects of EM on E. sinensis, we analysed the growth performance of E. sinensis after each moulting, examined the proximate composition, fatty acids, and flavour nucleotide composition of the edible tissues, as well as muscular amino acid composition in E. sinensis. In this study, we found EM could improve water quality by reducing total nitrogen and total phosphorus contents, while it had a weak promotion on the growth of crab. EM optimized the nutritional composition by improving the total lipid content in edible tissues, increasing beneficial fatty acid (C20:3) level in females and improving the nutritional value of muscular amino acid in males. Still, it caused a sweet taste loss by lowering the content of certain free amino acids especially Ala. However, EM increased umami or sweet taste contributors, that is AMP, GMP and IMP, and decreased off-flavour contributors, that is Hx and HxR. Thus, the overall flavour quality of edible tissues in female crab was greatly improved by EM. The present study provides us multiple influences of EM on the crab aquaculture, and we recommend supplementing EM into the diet for crab aquaculture in the future.