Chemical composition, cholesterol content and fatty acid profiles of common carp (Cyprinus carpio) from free-catch, semi-intensive and cage system

Abstract

Knowledge of the chemical composition of fish meat is important, as its consumption is increasing based on the recommendations that fish meat should be an essential component in a healthy diet. The main goal of this investigation was the determination and the comparison of the results obtained in the analysis of meat of common carp from free catch (the Danube), from the semiintensive system of rearing (fish farm 'Ečka') and from the cage system of rearing (cage system 'Vrbas'). The results obtained showed that there was statistically significant difference (P<0.05) in the content of fat (6.95; 3.14 and 9.79% respectively) and water (73.58, 78.31 and 70.32% respectively) in the examined groups of carp. It is important to stress that carp from the fish farm 'Ečka' contained less fat compared to carp caught in the Danube. There was no statistically significant difference regarding the protein content between tested groups. The amount of cholesterol in fish fillets was significantly higher in the samples of carp from Danube (45.49 mg/100 g) and 'Ečka' (49.64 mg/100 g) in comparison with the carp from cage system of rearing (26.53 mg/100 g), despite the significantly higher content of fat in the last mentioned group. Palmitic acid was the dominant saturated fatty acid (SFA) in all the groups, and there was statistically significant difference (P<0.05) regarding its content between the examined groups. The highest content was established in fillets of common carp from the Danube, which reflected on the total sum of SFA (Danube-27.59; Ečka-25.44 and Vrbas-17.18%), which was the highest in this group. The total amount of monounsaturated fatty acids (MUFA) was the highest in samples from the Danube (52.94%), and the lowest in carp samples from cage system (37.25%), although the content of predominant MUFA, oleic acid, was almost the same in all three groups. Total amount of polyunsaturated fatty acids (PUFA) was the highest in samples obtained from cage system of rearing( 45.46%), and the lowest was measured in samples from the Danube (19.60%), mostly because of high level of linoleic acid in the samples from cage system which was twice as high in comparison with the carp from 'Ečka', and almost five times in comparison with the carp from the Danube. The best ω-3/ ω-6 ratio was obtained for carps from free catch (the Danube), (0.44), and the worst for carps from cage system 'Vrbas' (0.10). This study contributes to a better understanding of the nutritional quality of carp from free catch (wild carp) and carp from aquaculture (cultured carp), and can help in the formulation of industrial feed mixtures for carp in order to achieve the optimum production results, a desirable quality of meat, and also the cost effective production.