以罗非鱼片为实验原料,研究了3种真空冷诱导前处理对罗非鱼片冰温贮藏过程中鲜度和滋味的影响。真空冷诱导初始温度均为12℃,设置了3种不同的真空冷诱导速度:1℃/h(方式I)、2℃/h冷诱导(方式II)和快速冷诱导(方式IU)。当鱼片温度降低到冰温带时,真空冷诱导结束,取出鱼片装密封袋冰温贮藏。对比了不同的真空冷诱导方式对罗非鱼片鲜度指标K值、肌苷酸(IMP)和主要滋味游离氨基酸的影响。冷诱导速度越浸,冷诱导时间越长,冷诱导结束时去除的水分越多,12h时K值略高,但在冰温贮藏过程中K值增长越缓厦,36h后K值反而最低,鲜度最好。在呈味游离氨基酸总量和游离氨基酸总量(TFAA)方面,真空冷诱导方式II优于方式I和方式ⅡI,方式I和方式III区别不明显。
Tilapia fillet was pretreated by three vacuum cold-induction methods including cooling at 1 ℃/la (mode I ), cooling at 2 ℃/h (mode II) and rapid cooling (mode III) with all initial temperatures of 12 ℃. When Tilapia fillets were cooled down to ice temperature, the tilapia fillets were taken out and packed into bags and stored at the temperature. The effect of different vacuum cold-induction methods on freshness index K value, inosine monophosphate (IMP) and the main flavor free amino acid were investigated and compared. The results showed that the vacuum cold-induction consumed longer time with the lower cooling-rate, and more moisture was removed, K value was increased slightly after 12 h, but reached the lowest after 36 h and the filapia fillets kept the best freshness. In terms of flavor free amino acid and total flee amino acids (TFAA), vacuum cold-induction mode II was better than mode I and mode III, and there was no significant difference between mode I and mode III.