高静压钝化树莓多酚氧化酶的动力学分析

Kinetic study of high hydrostatic pressure processing on polyphenol oxidase from raspberry

应用高静压技术钝化树莓中的PPO,以提高树莓加工产品的新鲜度和附加值。本文研究了高静压对树莓PPO的钝化效果,并应用一级动力学模型进行分析。研究结果表明,随着压力升高和持压时间的延长,树莓PPO的活性逐渐降低,但在低压短时处理下有激活现象,经600MPa,45min处理后树莓PPO残存活性为40.976%;高静压对树莓PPO的钝化过程符合一级动力学反应模型,压力对酶钝化反应的影响能用Eyring公式分析。随着压力升高,反应速率常数(k值)不断升高,指数递减时间(D值)不断减小;Zp和Va分别为917.431MPa和-6.020cm3/mol。

High hydrostatic pressure technique （HHP）was used to inactivate the polyphenol oxidase （PPO）of raspberry for making raspberry products fresher and raising their added value. The inactivation kinetics of polyphenol oxidase（PPO） under HHP was investigated. The results showed that the activity of raspberry PPO gradually decreased with the pressure increasing and/or the holding time extending, in spite that the PPO was activated under low pressure for short holding time.Residual activity of PPO was 40.976% treated by 600MPa for 45 minutes.Further,the inactivation of PPO under HHP can be adequately described by the first-order model, and the effect of pressure on the inactivation of PPO can be analyzed with Eyring equation.With the pressure increasing, the PPO inactivation rate constants k increased and the decimal reduction time D reduced.The Zp and Va were 917. 431 MPa and-6.020cm^3/mol respectively.