Dietary phospholipids improve growth performance and change the lipid composition and volatile flavor compound profiles in the muscle of abalone Haliotis discus hannai by affecting the glycerophospholipid metabolism

A 106-day feeding trial was conducted to investigate the effects of dietary phospholipids on growth performance, volatile flavor compounds as well as the lipid composition in abalone Haliotis discus hannai. Abalones (initial weight: 16.19 +/- 0.16 g) were fed with graded levels of dietary phospholipids (0.10 %, 0.30 %, 0.69 %, 1.30 %, 1.83 % and 2.48 %). Results showed that weight gain rate (WGR) were highest in 1.83 % dietary phospholipids level. Based on the quadratic regression analysis for WGR, the optimal dietary phospholipids level for abalone was estimated to be 1.57 %. The contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in abalone muscle increased gradually with the increase of dietary phospholipids levels. A total of 25 volatile flavor compounds were detected in the muscle of abalone by gas chromatograph-ion mobility spectrometry (GC-IMS), including 9 aldehydes, 6 esters, 4 ketones, 3 alcohols and 3 hydrocarbons. The content of some volatile flavor compounds with pleasant aroma in the muscle of abalone increased significantly when fed with diets containing 1.83 % and 2.48 % of phospholipids. Lipidomics analysis showed that dietary phospholipids could affect the lipid composition in the muscle by reducing the synthesis and promoting the decomposition of phospholipids. Among 244 differential lipids identified by lipidomics, phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) were the main species, accounting for more than 50 % of them. Partial least squares regression (PLS-R) analysis showed that the changes of volatile flavor compounds in the muscle of abalone was strongly related to PCs and PEs. Altogether, the present study suggested that dietary phospholipids can not only improve the growth per-formance and nutritional value of abalone, but also have the potential to improve the flavor quality of abalone.