摘要
研究了高压脉冲电场(PEF)对梨汁的杀菌钝酶效果的影响。结果表明,当电场强度30kV/cm,处理时间200μs,10℃水浴温度时,沙门氏菌数量最大降低了3.4个数量级。温度具有辅助杀菌效应,当样品温度从10℃上升至40℃时,沙门氏菌致死率进一步提高了1.8个数量级。脉冲电场能够降低梨汁中多酚氧化酶的活性,但多酚氧化酶对脉冲电场的抗性比微生物强,在0～20kV/cm范围的电场强度下,PEF对PPO几乎无影响;电场强度25kV/cm后,酶活显著下降。温度升高会加速多酚氧化酶的灭活,电场强度30kV/cm,时间1200μs,温度由10℃上升至40℃时,残留酶活从33.3%下降至13.2%。因此,PEF能有效杀灭梨汁中的微生物,并且能钝化其中的多酚氧化酶。
Pulsed electric fields （PEF） was applied to the pasteurization and enzyme inactivation of pear juice. The result showed that the inactivation of Salmonella in the inoculated pear juice by the PEF treatment at 30kV/cm for 200μs reached 3.4 lg reduction cycles in a 10℃ water bath. With the promotion of temperature from 10℃ to 40℃, the reduction of Salmonella increased by 1.8 lg cycles. Pulsed electric field also had the effect on the activation of polyphenel oxidase in pear juice,but it was less sensitive to PEF than microorganism. The PEF treatment has little influence on PPO when electric field strength ranged from 0 to 20kV/cm. However,enzyme activation significantly decreased when electric field intensity reached 25kV/cm. The temperature of the water bath had critical influence on enzyme. The higher the temperature,the more effective the PEF inactivation of polyphenol oxidase. From 10℃ to 40℃ the residual PPQ activation ranged from 33.3% to 13.2% at 30kV/cm for 1200μs. it was concluded that PEF could effectively inactivate the microbe and decreased the activation of PPO.
出处
《食品工业科技》
CAS
CSCD
北大核心
2008年第11期65-68,共4页
Science and Technology of Food Industry
基金
"十一五"国家支撑计划项目(2006BAD05A02)
关键词
高压脉冲电场
梨汁
沙门氏菌
多酚氧化酶
pulsed electric fields
pear juice
Salmonella
polyphenol oxidase
