Determination of Proximate Composition and Lipid Deterioration in Various Parts of the Gibel Carp (Carassius gibelio)

This study explores the potential utilization of meat, scales, viscera, and bony structures of gibel carp (Carassius gibelio), an invasive and economically underutilized species from the Black Sea, as alternative lipid sources for human consumption and functional ingredients in animal feed. The nutritional composition analysis showed significant differences among tissues: the meat contained 14.98% protein and 1.43% lipids, while the viscera exhibited the highest lipid content (22.38%) but the lowest protein level (1.08%). The scales had the highest protein (21.31%) and ash (9.07%) contents, while the bony structures contained significant levels of protein (18.38%), lipids (2.59%), and ash (7.20%). Lipid oxidation parameters indicated that the viscera had the highest peroxide value (3.8 meq O₂/kg), whereas the scales had the lowest (2.47 meq O₂/kg). Thiobarbituric acid (TBA) and free fatty acid (FFA) values demonstrated better oxidative stability in meat and bony structures compared to the viscera. These findings demonstrate the potential of utilizing Gibel carp by-products as alternative raw materials for a variety of applications. This approach supports sustainability and the principles of the circular economy, providing an innovative way to turn an invasive species into valuable resources.