冻融预处理对罗非鱼片热泵干燥特性的影响及响应面法优化

Effect of freeze-thaw pretreatment on tilapia fillets heat pump drying characteristics and the optimization by response surface method

以罗非鱼为原料,采用单因素试验法和响应面分析,研究冻结温度、融化温度、冻结时间和解冻时间4个冻融预处理条件对罗非鱼片热泵干燥过程和干制品品质的影响。结果显示:4个冻融预处理工艺条件都不同程度地影响罗非鱼片的热泵干燥性能,其最佳冻融预处理条件为:冻结温度-32℃、融化温度20℃、冻结时间1.0 h、融化时间87 min。在此条件下对罗非鱼片进行预处理,后利用热泵将罗非鱼片干燥到干基含水率为0.30(±0.02)g/g,用时10 h,所得干制品的肌原纤维蛋白Ca^(2+)-ATP酶活性为2.33μmol Pi/(mg prot·h),复水率36.22%,硬度9.8 N。相比于常规热泵干燥方式,该工艺缩短了罗非鱼片的干燥时间,提高了干制品品质。

Four freeze-thaw pretreatment conditions including freezing temperature, thawing temperature, freezing and thawing time on the effect of tilapia fillet heat pump drying process and product quality were studied using single-factor experiment and response surface analysis with tilapia as material. The results showed that ： all of those four pretreatment processes of freeze-thaw conditions had effects on Tilapia fillets heat pump drying performance in varying degrees. The best freeze-thaw pretreatment process was： freezing temperature - 32 ℃, thawing temperature of 20 ℃, freezing time of 1.0 h, and the thawing time of 87 rain. On this condition, 10h were spent on drying the moisture content of drying base to 0.30 （ ±0.02）g/g. The Ca2＋-ATPase activity of myofibrillar protein of dried products was 2. 33 μmol Pi/（ mg prot · h）, the rehydration ratio was 36.22%, and the hardness was 9.8N. The drying time of tilapia fillets was shortened and the quality of the dried products was improved by using this way compared with the conventional heat pump drying methods.