The effect of different salt concentration and time combinations in physicochemical properties and microstructure of Russian sturgeon (Acipenser gueldenstaedtii) fillets under vacuum impregnation

Salting is important to maintain the food quality. This study aimed to evaluate the physicochemical properties and microstructure of Russian sturgeon fillets under vacuum impregnation and find out appropriate salting conditions. The treatments varied in salt concentration (5%, 10%, 15%, and 20%) and time (1, 2, 3, 4, and 5 hr); samples treated under atmospheric pressure with 10% were included as controls. In our study, vacuum impregnation improved the salting efficiency and helped to maintain a complete microstructure to enhance the water‐holding capacity, especially after salting for 2 hr, the maximum value was 32.4%. Moreover, it increased the values of hardness and springiness and reduced L* and a*. In addition, the fillets under vacuum impregnation had lower TVB‐N and Carbonyl content, which were 15.91 mg/100 g and 311.38 nmol/L after salting for 5 hr, respectively. Consequently, vacuum impregnation was a better way of salting for its higher salting efficiency and better physicochemical properties. Practical applications The results of this study provide information to food industry about the effects of different salt concentration and time under vacuum impregnation on the Russian sturgeon fillets. It can be seen from the results that vacuum impregnation can improve the salting efficiency and protect the original organizational structure as completely as possible. As a result, vacuum impregnation is a better way of salting.