鲣鱼罐头的变温与恒温杀菌工艺比较

基于F0=20 min的恒温杀菌工艺，本研究提出2 种具有相同F0值的不同变温杀菌工艺，并与恒温杀菌工艺进行比较。对杀菌锅和罐头冷点的温度变化进行实时监测，并记录温度变化曲线用于分析。结果显示，不同杀菌工艺具有不同的温度、时间组合和相同的F0值。较优变温杀菌工艺（105 ℃-115 ℃-120 ℃-125 ℃，每阶段持续2.5 min）与恒温杀菌工艺相比，罐头样品中鱼肉的硬度提升22.8%、弹性提升6.9%、内聚性提升20.5%；罐头样品中汤汁的浊度下降29.41%、粗蛋白含量下降48.13%；罐头样品的挥发性盐基氮值下降了20.14%。肌肉横切面扫描电子显微镜结果显示，变温杀菌工艺对鱼肉组织结构的破坏程度更小。由此可见，采用变温杀菌工艺可以减少鲣鱼罐头因杀菌造成的品质降低。

Comparison of Constant-Retort-Temperature and Variable-Retort-Temperature Sterilization Processes for Canned Skipjack

Two variable-retort-temperature (VRT) sterilization processes were presented according to the constant-retorttemperature
(CRT) process with F0 = 20 min and the two VRT processes were compared with the CRT process. The heating
histories of the retorts and cool points were plotted and analyzed. The results showed that the three methods had the same
F0 value but different combinations of temperature and time. Compared with the CRT process, the better VRT process
(105 ℃-115 ℃-120 ℃-125 ℃ for 2.5 min at each temperature) resulted in 22.8%, 6.9% and 20.5% increases in the
hardness, springiness and cohesiveness of skipjack meat and 29.41%, 48.13% and 20.14% decreases in turbidity and crude
protein content of the broth, respectively. The muscle tissue of skipjack was less disintegrated by the VRT sterilization
processes, as shown by observation of the cross-sectional microstructure of muscle. All these results showed that the
variable-retort-temperature sterilization processes could reduce the quality loss of canned skipjack compared with the
constant-retort-temperature process.