The Optimization of Sodium Tripolyphosphate Treatment Conditions on the Weight of Giant Freshwater Prawns (Macrobrachium rosenbergii) during Frozen Processing.

Abstract

During the frozen processing of giant freshwater prawns (Macrobrachium rosenbergii), the average weight loss after thawing is high. Overcoming this problem will be an economic benefit and has a significant implication for its large-scale production for seafood producers and traders. Sodium tripolyphosphate (STPP) is a common additive and is irreplaceable for retaining water in seafood products. Identifying optimal STPP treatment conditions for frozen M. rosenbergii to minimize weight loss is important to the seafood processing industry. In this study, we examined the effect of STPP on the weight of frozen M. rosenbergii. STPP treatment included the following factors: (1) time (min), (2) temperature (°C), and (3) concentration (%). The factors were optimized by response surface methodology using a centered second-order rotation model (central composite design) to gain the lowest weight loss rate of M. rosenbergii during frozen processing. The results indicated that with an STPP concentration of 3.56%, a temperature of 15.8°C, and a time of 54 min, the lowest weight loss of M. rosenbergii was 6.4%. The chemical composition of STPP-treated giant freshwater prawns after thawing were as follows: water content 82.3%, NH₃ content 6.3%, and total nitrogen 3.8% (the composition of the original raw materials were 77.7%, 6.7%, and 4.9%, respectively).