Biometric and metabolic profiles associated to different rearing conditions in offshore farmed gilthead sea bream (Sparus aurata L.)

Abstract

Modern multivariate methods are applied to both biometric measurements and NMR metabolic profiling of fillet to discriminate farmed gilthead sea bream reared in different farming conditions. Two fish groups having the same average size, from the same farm, were caught in May and October. Biometric data demonstrate that condition factor is higher for the leaner fish, sampled in May, while liver somatic index is lower in fish sampled in October. Biometric features are related to metabolic changes that involve lipid storage from May to September, and their mobilization from muscle and liver during prespawning season (September, October). Structural phospholipids (phosphatidylcholine, phosphatidylethanolamine) and essential fatty acids (eicosapentaenoic and docosahexaenoic acids) characterize the lipid profile of the May catch, while triglycerides, monounsaturated and diunsaturated fatty acids, likely from absorption of vegetable oil components of feeds, suggest fish fattening in the warm season and discriminate fish caught in October. Among polar metabolites, taurine, glutamine, glycine, alanine, and creatine/phosphocreatine confirm their role as good biomarkers for the discrimination among fish produced in different farming conditions, especially involving feed digestion and metabolism, chronic stress, and alteration of energetic balance in cage-reared fish. Qualitative traits of farmed fish are therefore the result of a complex combination of environmental factors and farming practices, which should be analyzed to increase consumers' and farmers' awareness.

Metabolomics and fish nutrition: a review in the context of sustainable feed development

“…In this study, the contents of DHA and EPA were nearly twofold higher in wild fish muscles. A further accumulation of MUFA and DUFA was also observed in 1 H‐NMR profiles in muscle of gilthead sea bream fed highly substituted FM by plant meals and vegetable oils (Melis & Anedda ). However, in this experiment, there was a potential interaction with other confounding factors (season combined with sexual maturation, water temperature, feed change), so the effect of diet should be interpreted with caution.…”

“…In line with these results observed in liver, choline and its metabolites were also modulated in muscle of fish fed plant‐based or commercial diets (Mannina et al . ; Melis & Anedda ; Maruhenda Egea et al . ).…”

“…). Finally, biological factors such as sexual maturation induce changes related to decreasing muscle fat content (Melis & Anedda ; Zhou et al . ), and amino acid and unsaturated fatty acid profiles differ in zebrafish ( Danio rerio ) liver according to their gender (Ong et al .…”

“…An 1 H‐NMR‐based fingerprinting strategy on lipid muscle extracts successfully separated wild sea bream from farmed sea bream (Rezzi et al . ; Melis & Anedda ). Moreover, multivariate analysis on NMR muscle profiles partially discriminated fish geographic origins.…”

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…Several of the Foodomics works recently published have involved the use of NMR or other liquid techniques (e.g. UHPLC, nano‐LC) hyphenated to HRMS .…”