多酚氧化酶高强度脉冲磁场灭活及动力学模型

    Inactivation of polyphenol oxidase by high-intensity pulsed magnetic field and kinetic model

    • 摘要: 为了找到一种有效控制果蔬中多酚氧化酶(PPO)活性的方法,该文研究了高强度脉冲磁场(PMF)对PPO活性的影响,并进行了灭酶动力学模型的研究。结果表明,当PPO于磁场强度2.5、3.5和4.5特斯拉(T)分别处理5至40个脉冲时,酶的残余活性随着磁场强度和脉冲数的增加而逐渐降低。在4.5 T处理40个脉冲时,酶的灭活率最高达到93.10%。对灭活动力学曲线分别用Bigelow模型、Weibull模型和Hülsheger模型进行拟合,发现Weibull模型对PMF下PPO的灭活的拟合度最好。可见,高强度脉冲磁场可以作为一种有效杀灭果蔬中多酚氧化酶的非热技术,且酶的灭活过程符合Weibull模型,该模型可以为实际应用提供参考。

       

      Abstract: In order to find an effective method to control the activity of polyphenol oxidase (PPO) in vegetable and fruit, the effects of pulsed magnetic field (PMF) on the activity of PPO were investigated. The data were adjusted to different models to study the kinetics of PPO inactivation by PMF. The results showed that when PPO was exposed to PMF at field strengths of 2.5, 3.5 and 4.5 tesla (T) for 5 to 40 pulses, residual activity of PPO decreased with the increase of field strength and number of pulse. The maximum inactivation of PPO was achieved at 4.5 T for 40 pulses, in which 93.10 % of the enzyme activity was lost. The inactivation data were fitted by three kinetic models, which were Bigelow Model, Hülsheger Model and Weibull distribution function. Results showed that Weibull distribution function gave better fittings for the inactivation of PPO by PMF than Bigelow or Hülsheger models. It can be concluded that PMF is an effective non-thermal food preservation technology to inactivate PPO in vegetable and fruit. Weibull Model fits the inactivation data well, which provides reference for practical application.

       

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