Seasonal changes in meat content, condition index and chemical composition of mussels (Mytilus galloprovincialis) cultured in two different Italian sites

Seasonal changes, occurring during a 1-year period, in mussels (Mytilus galloprovincialis), cultivated in long-line plants in two different Italian sites, one off the northern Adriatic coast and the other in a sea lake along the Central Tyrrhenian coast, were investigated. Biometric parameters, percent meat and intervalval fluid contents, Condition Index, proximate composition and lipid profile of mussels were studied. The low meat content and Condition Index values registered in December, in mussels from the Adriatic site (142.0±9.9), and in September, in mussels from the Tyrrhenian sea lake (126.0±2.3) were coincident with the depletion of glycogen and lipid reserves. Gas chromatographic analysis of total lipids showed the prevalence of polyunsaturated fatty acids (37–48% of total fatty acids) over the saturated (26–38%) and monounsaturated (16–29%) ones throughout the year. Seasonal fluctuations of vitamin A, vitamin E, cholesterol, phytosterols and carotenes levels, in mussels from either site, were detected by high performance liquid chromatography.