Krill oil showed a good application potential as the dietary lipid source on the growth, physiology, nutritional quality, and flavor of the edible meat of the oriental river prawns (Macrobrachium nipponense)

Abstract

An 8-week feeding trial was conducted to evaluate the effects of dietary krill oil (KO), fish oil (FO) and soybean oil (SO) on growth, nutritional quality and flavor of the edible meat of the oriental river prawns (Macrobrachium nipponense). The results revealed that SO and KO diets promoted the growth performance (P < 0.05). The activity of alanine aminotransferase in hemolymph of the FO group was significantly lower than that in the SO group (P < 0.05). The contents of total cholesterol in hemolymph in the SO and FO groups were significantly lower than those in the KO group (P < 0.05). Superoxide dismutase activity and glutathione content in the hepatopancreas were the lowest in the SO group (P < 0.05). Lipoprtein lipase and trypsin activities of the hepatopancreas decreased significantly in the KO group (P < 0.05). Among the fatty acids in meat, the contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased significantly in M. nipponense after feeding on animal lipid sources (FO and KO) (P < 0.05). The contents of umami and bitter free amino acids in the SO and KO groups were significantly higher than those in the FO group (P < 0.05), and the contents of adenosine monophosphate and inosine monophosphate were highest in the KO group (P < 0.05). The contents of bitter nucleotides hypoxanthine and hypoxanthine ribonucleoside were lowest in the KO group (P < 0.05). In general, compared with FO, the use of KO and SO as lipid sources in feed promoted the growth of M. nipponense, and KO significantly improved the antioxidant index of the hepatopancreas. FO and KO increased the contents of EPA and DHA in the edible meat of M. nipponense, and KO further enhanced the contents of amino acids and nucleotides responsible for flavor in the meat.