巴氏杀菌对NFC苹果汁杀菌效果及品质的影响

为研究巴氏杀菌对非浓缩还原汁(NFC)苹果汁的杀菌效果及动力学规律,对不同杀菌温度时间下NFC苹果汁菌落总数变化进行测定,并通过总酸、VC、色泽等品质指标进行分析,探讨不同杀菌条件对NFC苹果汁品质的影响。结果表明,随着加热处理温度的升高以及时间的延长,杀菌效果显著增强。对不同热处理条件下的NFC苹果汁的杀菌效果进行动力学分析,均符合一级动力学模型,拟合后各决定系数R²均大于0.9。建模分析表明,在70,75,80,85和90℃下保温58.14,44.64,18.28,9.92和4.96 min,可使微生物下降一个数量级。而要达到相同致死效果,并使灭菌时间减少到原来的1/10,所需升高的温度为17.61℃。此外,对巴氏杀菌后NFC苹果汁进行品质分析,与未处理相比,其在总酸、pH、可溶性固形物方面无显著影响,高温短时杀菌能更好保持果汁的色泽和营养成分。

The Effects of Different Sterilization Conditions on Efficiency and Quality in NFC Apple Juice

To study microbe inactivation effect and kinetics of pasteurization on NFC(not from concentrate)apple juice,the changes of the total plate count in NFC apple juice under different sterilization temperature and time were measured,and through the analysis of total acid,VC,color and other quality indicators,the effect of different sterilization conditions on the quality of NFC apple juice was explored.The results showed that with an increase in either temperature or time,sterilization effect increased significantly.The kinetic analysis of the sterilization effect of NFC apple juice under different heat treatment conditions followed the first-order kinetic model,and the determination coefficients R²were greater than 0.9 after fitting.The modeling analysis showed that the juice at 70,75,80,85 and 90℃for 58.14,44.64,18.28,9.92 and 4.96 min could result in a decimal change.To achieve a same sterilization effect,when the sterilization time was reduced to 1/10 of the original,the temperature increased 17.61℃.In addition,through the quality analysis of NFC apple juice after pasteurization,it had no significant effect on total acid,pH,soluble solids and high-temperature-short-time,and it could better maintain the color and nutrition of the juice.