Comparison of malondialdehyde concentrations in different muscle areas of tench Tinca tinca L

The concentration of malondialdehyde (MDA), a marker of lipid peroxidation changes, was measured in the muscles of male and female common tench (Tinca tinca L.). Differences in MDA concentrations were determined in samples in cranio-caudal and dorso-ventral directions and in surface and deep muscle layers. Mean MDA concentration in both sexes (n=27) was 0.037 μmol g-1 tissue (wet weight), with the highest levels in the cranial segment. The difference between the cranial and other segments was significant (p < 0.05 in males andp < 0.01 in females). HigherMDAvalues were found in the cranial segment (malesp < 0.05, femalesp < 0.01), in females in ventral part of the cranio-medial segment, in males in the ventral part of the medio-caudal and dorsal parts of the caudal segment (p < 0.05). Both sexes had higher MDA levels in the ventral parts of the first three segments and in the dorsal part of the caudal segment. The results show lipid peroxidation products that may constitute a potential risk for consumers. We found that the content of these substances in tench varies with body topography. The malondialdehyde content of fresh muscle tissue in tench correlated with its content on a fat weight basis. The highest correlation was found for the dorsal part of segments in females (r = 0.9964), the lowest for ventral parts of segments in males. Quantitative distribution of MDA in body segments of the examined tench population was used as a criterion for creating types and subtypes of lipid peroxidation. Samples for hygienic analysis should include musculature from the site least stable in terms of lipid peroxidation, i.e. the cranial segment.[PUBLICATION ABSTRACT]