Effect of treatment with electrolyzed NaCl solutions and essential oil compounds on the proximate composition, amino acid and fatty acid composition of carp fillets

This investigation was undertaken to evaluate the effect of treatment with electrolyzed NaCl solutions and 1% essential oil (0.5% carvacrol + 0.5% thymol) on the proximate composition and nutritional components (amino acids and fatty acids) of carp fillets at room temperature (25 °C). Carp fillet samples were treated with anodic electrolyzed NaCl solution [EW (+)], cathodic electrolyzed NaCl solution [EW (−)] followed by EW (+) [EW (−)/EW (+)], 1% essential oil (0.5% carvacrol + 0.5% thymol) [1% (Cv + Ty)], EW (+) followed by 1% (Cv + Ty) [EW (+)/1% (Cv + Ty)] and EW (−) followed by EW (+) and finally with 1% (Cv + Ty) [EW (−)/EW (+)/1% (Cv + Ty)]. Proximate composition, SDS–PAGE, amino acid composition, digestibility and fatty acid composition were used to determine the changes in carp fillet composition. Moisture, total lipid, total protein, ash and carbohydrate contents of the carp fillets were approximately 76%, 3.9%, 17.5%, 1.0% and 0.40%, respectively. The dominant amino acid was glutamic acid, and the composition ranged from 14.2 to 14.5 mol%. Protein digestibility of the carp fillets was approximately 85%. Oleic acid was the major monounsaturated acid in the carp fillets (41.0–41.9%). These results show that our method of fish preservation, using electrolyzed NaCl solutions and 1% (Cv + Ty), did not affect the quality (nutritional components) of carp fillets, and could be a good alternative to synthetic preservatives routinely used in the food industry.