The effect of walnut feed on the carp’s (Cyprinus carpio L.) meat quality, fatty acid composition and consumer perception

Abstract

In our experiment, we compared walnut processing waste fed carp with traditionally raised carp on grain from a meat quality aspect. Conventional meat quality parameters (water holding capacity, flesh color and pH), fillet fatty acid profile and consumer perception were determined in 9 fish from each group. Significant differences were found between the groups using independent samples t-test. The fish fed walnuts had better fillet water holding capacity. In the color of fillets significant differences were found. Walnut fed carp’s meat was darker than normal. In the data of the fatty acid analysis we found significant differences not just by individual fatty acids, but also in the derived fatty acid data. The walnuts significantly reduced the level of the saturated fatty acids and increased the proportion of polyunsaturated fatty acids. Although walnut is a n6 fatty acid source, the n6/n3 ratio also shows a significantly positive value, than the grain fed fish. The consumer's perception of the walnut-fed carp in many respects got better score compared to the other group. The judges felt the meat of the walnut fed carp less greasy, than the other one and the overall impression were better, too. According to our results, by the effect of walnut diet the product can represent a higher value on the market, than the traditionally grain fed carp’s meat.