Abstract: The respective amounts of sodium diacetate, sodium lactate and potassium sorbate added together to high-moisture roasted shrimp were optimized using a three-variable quadratic orthogonal rotation combination design. Aerobic plate count of high-moisture roasted shrimp with preservative treatments after 10 d of storage was used as response dependent variable. The results show that in decreasing order, the antimicrobial effects of the preservatives were sodium lactate, potassium sorbate and sodium diacetate. There were no significant interaction effects among them. The optimum amounts of sodium diacetate, sodium lactate and potassium sorbate added to high-moisture roasted shrimp were 0.44, 22.60 g/kg and 0.55 g/kg, respectively, resulting in minimum logarithmic aerobic plate count of 2.26 (lg(CFU/g)) as predicted by the developed regression model, that is, the aerobic plate count is 180 CFU/g. The relative error between the predicted logarithmic aerobic plate count and its actual counterpart was 3.55%, suggesting that this regression model was reliable.

Key words: roast shrimp, preservation, antibacterial effect, interaction