Salt alcohol additive pre-treatment to improve the performance of heat pump dried tilapia fillets

In order to obtain the effect of salt alcohol drying additive pretreatment on the drying performance of tilapia heat pump, three pre-treatment methods of propylene glycol, glyceryl alcohol and NaCl were used to pretreat the tilapia fillets. And the drying time, water activity, rehydration rate and Ca2 + -ATPase activity as the measurement index of a series of experiments, The change law of the drying curve, water activity, rehydration rate and Ca2+-ATPase activity were obtained. The results showed that the penetration dehydration effect of propylene glycol and glycerol is not as obvious as sodium chloride. These three increase Ca2+-ATPase activity at different levels. And they reduce the water activity of dried tilapia fish, and the capability of them: sodium chloride>glycerol>propylene glycol. Glycerol and propylene glycol can increase the rehydration rate while sodium chloride lessens it. Based on the results, the response surface analysis was used to optimize while the water activity and the Ca2 + -ATPase activity were taken as the response values. Investigating interaction between several pretreatment reagents, a combined pretreatment method was obtained: Propylene glycol 2% + glycerol 3% + NaCl 1%. Therefore, the appropriate pretreatment reagents and their combinations can be selected according to the concerns of the different quality indexes of the samples, and the conclusion can provide a reference for the drying pretreatment of similar products.