Study of the effect of nitrite salt on the color formation of dried products from mirror carp (Cyprinus carpio) and silver carp (Hypophthalmichthys)

Color is a key factor determining the consumer appeal of food products such as sausages. In this study, the effect of nitrite salt on the color formation of molded dried products in a shell of muscle tissue of mirror carp (Cyprinus carpio) and silver carp (Hypophthalmichthys) grown in the Kaliningrad region was studied. RGB and CIELAB color models were used to represent and describe colors digitally. The obtained color coordinates made it possible to describe the dynamics of color changes in dried fish sausage products during the drying process. It was found that dried carp products changed their color characteristics from yellowish-gray to pearl-beige, while carp samples showed a transition from pink-brown to gray-purple. The differences in the color coordinates (ΔE) of the samples with different nitrite salt content did not exceed the threshold value of perception by human visual organs. The analysis of physico-chemical parameters showed that the nitrite salt has no significant effect on changes in such indicators as active acidity, water activity and the content of formally titrated nitrogen (FTN) in samples of finished dried products. By the end of drying, the values of these indicators for all samples were close and amounted to 5.83-5.89 pH for carp products, 0.805-0.813 water activity and a pH content of 174.61-179.3 mg/100 g, and 5.96-5.99 pH for carp products, 0.774-0.781 water activity and FTN value of 180.25-183.75 mg/100 g. Studies have confirmed that nitrite salt has a minimal effect on the color formation of dried fish products, which is associated with a significantly lower content of myoglobin in fish muscle tissue compared to meat products, and, consequently, color differences are due to the nature of the raw materials and biochemical processes occurring in the muscle tissue.