Abstract: In order to predict peroxidase (POD) activity and prevent over-blanching-induced damage of asparagus lettuce, thermal inactivation of POD in asparagus lettuce was explored and kinetic models were established at temperatures ranging from 75 ℃to 95 ℃. First-order kinetic model and Weibull distribution model were employed to fit the inactivation characteristics of POD. Two models were evaluated based on the coefficients of determination (R2) and chi-square (χ2) for the application of actual prediction. Moreover, blanching conditions of asparagus lettuce were optimized according to the change of vitamin C content. The results indicated that Weibull distribution model could better describe POD inactivation kinetics in asparagus lettuce over the selected temperature with a highR2(＞0.9900) and low χ2(＜ 0.0024). Meanwhile, high-temperature short-time blanching treatment could result in less loss of vitamin C.

Key words: peroxidase, kinetics, blanch, asparagus lettuce, model