Optimization of soaking treatment on the quality of Pangasius fillet

In Pangasius fillet industries, soaking fillet with food additives such as sorbitol, sodium tripolyphosphate (STPP) and sodium chloride (NaCl) is a common practice to increase the quality of fillets. In this study, the fillets were soaked with different concentrations of sorbitol (1.32-4.68%), STPP (0.32-3.68%) and NaCl (1.32-4.68%) by using response surface methodology (RSM) with Central Composite Design with six replicates experimental design. The soaking solutions had a significant impact on weight gain, pH and water activity (p<0.05). The soaking solution of NaCl 1.32%, STPP 1.88% and sorbitol 4.68% were optimal using multi-response optimizer. In addition, the optimum soaking time was studied from 15 to 60 mins. The results showed that soaking time should be appropriated for 30 mins. The optimum concentration and time of soaking can be considered as a practical pre-treatment to improve the quality of Pangasius fillets either for fresh, chilled, or frozen storage.