Effect of Two Kinds of Osmotic Media on Quality of Tilapia Fillets

Abstract

In order to search effect of osmotic medium on quality of tilapia fillets treated by different kinds of osmotic solution, the changes in pH value, lightness (L*) degree and electrical conductivity (EC) were quantitatively determined during osmotic treatments for fresh tilapia fillets with the osmotic medium (sodium chloride, sucrose),medium concentration (10-30%) and osmotic time (1-5hour) as the independent treatment factors. Results were as follows: (1) L* and pH of the fish fillets were decreased gradually, color darkened slightly, and EC was increased with increase in osmotic time when fresh tilapia fillets were soaked in sodium chloride (NaCl) solution and sucrose solution, respectively. (2)Effects of two kinds of osmotic media on quality of fish fillets were different during osmotic treatment period. First, the changes in pH, L* and EC of fish fillets were bigger in the NaCl solution, and smaller changes in the sucrose solution. Second, pH of fish fillets in the NaCl solution was always lower than that of sucrose solution, but EC of fish fillets in the NaCl solution was significantly higher than that of sucrose solution.(3)Highly significant correlation of EC and osmotic time were observed, and the regression equations were established according to the results of influence on EC of fish fillets in the process of osmotic dehydration.