高压脉冲电场对鲜榨梨汁的杀菌效果及其对产品品质的影响  

Effect of pulsed electric fields on inactivation of microbe and quality of freshly-squeezed pear juice

作　　者：赵瑾[1] 杨瑞金[2] 赵伟[1] 马松杉[3] 王艳芳[1] 

机构地区：[1]江南大学食品科学与技术国家重点实验室,无锡214122 [2]江南大学食品学院,无锡214122 [3]无锡南洋职业技术学院,无锡214081

出　　处：《农业工程学报》2008年第6期239-244,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：“十一五”国家支撑计划项目“食品冷加工与高效分离技术项目”(2006BAD05A02)

摘　　要：为了采用非热杀菌技术以生产高质量的果汁,研究了高压脉冲电场(PEF)对梨汁的杀菌效果及其对产品品质的影响。结果表明,当电场频率、电场强度和处理时间、温度分别为200Hz、30kV/cm和240μs、10℃时,梨汁中接种的大肠杆菌、酿酒酵母的数量分别下降4.6、2.7个数量级。温度具有辅助杀菌效应,相同频率和场强下处理时间200μs,当样品温度从10℃上升致40℃时,大肠杆菌致死率提高了1.4个数量级,酿酒酵母致死率提高了2.0个数量级,未接种鲜榨梨汁的细菌致死率提高了2.0个数量级,霉菌酵母致死率提高了1.0个数量级。PEF处理后梨汁理化性质、营养成分比热处理更接近原样。气相色谱-质谱(GC-MS)对梨汁风味物质进行检测的结果表明,梨汁中含量最多的挥发性风味物质为酯类,与传统热处理相比,PEF处理对梨汁风味物质的影响较小。因此脉冲电场不仅有较好的杀菌作用,并且最大限度地保证了梨汁的品质。To evaluate the application of non-thermal processing technology on the processing of freshly-squeezed pear juice, the effects of pulsed electric fields on inactivation of microbe and quality of freshly-sequeezed pear juice were investigated.The results showed that E. coli and S. cerevisiae inoculated in pear juice reduced by 4.6 and 2.7 in logarithm when exposed to Pulsed Electric Fields（PEF） at 200 Hz, 30 kV/cm, 10℃, for 240μs, respectively. With the promotion of temperature from 10 to 40℃, the reduction of E. coli and S. cerevisiae innoculated in pear juice, the total count of bacteria colonies, yeast and mold in the freshly-squeezed pear juice increased by 1.4, 2.0, 2.0 and 1.0 in logarithm, respectively by PEF treatment at 200 Hz, 30 kV/cm for 200μs. The pear juice after PEF treatment was more close to untreated pear juice than the pasteurized pear juice in physico-chemical properties and nutrition .The result of Gas Chromatography-Mass Spectrometric（GC-MS） showed that the main volatile aroma compounds in pear juice was ester, and the treatment of PEF brought less influence on juice flavor than conditional thermal sterilization. It is concluded that PEF treatment can effectively inactivate the microbe and maintain the flavor and quality of pear juice.

关 键 词：高压脉冲电场 杀菌 梨汁 品质 

分 类 号：TS225.3[轻工技术与工程—粮食、油脂及植物蛋白工程]