Impact of Sex and Fishing Season on Fatty Acid Profile, Fat and Cholesterol Content in the Meat of Roach (Rutilus rutilus L.) from Brda River (Poland)

Abstract

The aim of this study was to determine fat and cholesterol content and the fatty acid profile in the meat of roach (Rutilus rutilus L.). Muscle samples for analyses were taken from the large side muscle of the fish body above the lateral line. The study involved 56 individuals caught in fall and spring. Analyses were carried out on 14 females and 14 males caught in each season. The percentage content of fat in the fish meat was determined with the modified method of FOLCH et al. (1957). The cholesterol content was determined with the modified Liebermann-Burchardt colorimetric method using a Shimadzu spectrophotometer (UV-VIS-NIR-3100). The fatty acid profile was determined with the gas chromatograph with a flame-ionization detector. Analyses indicated that the percentage content of fat was higher in the meat of roach caught in autumn (0.96% in females and 0.91% in males) than in the tissues of individuals from spring, which was 0.67% and 0.86%, respectively. The content of the total cholesterol was higher in autumn (64.17 mg 100g(-1)) than in spring (56.25 mg 100g(-1)), and these values significantly differed (p < 0.05). Statistical analyses indicated that there were no significant differences in the content of fat and cholesterol between females and males caught in both seasons. The total amounts of SFA, MUFA and PUFA ranged from 30.05% to 33.57%, from 39.53% to 47.64% and from 19.96% to 27.42%, respectively. Analyses of correlations between fatty acids from the n-3 and n-6 group indicated a positive and statistically significant relationship between C20:4 n-6 and C22:4 n-6 (p = 0.000, R = 0.9065) and C20:5 n-3 and C22:6 n-3 (p = 0.000, r = 0.8555). The ratio of n-3/n-6 was highest in the meat of roach caught in spring (0.50-0.81) than in autumn (0.50-0.77). The AI index ranged from 0.35 to 0.46 and the mean values of TI ranged from 0.41 to 0.54.