Modeling the inactivation kinetics of polyphenol oxidase and peroxidase during the cold plasma treatment of kiwifruit juice

Abstract Cold Plasma (CP) is an emerging non‐thermal technology that preserves and decontaminates food. Kiwifruit juice spoilage enzymes polyphenol oxidase (PPO) and peroxidase (POD) were studied at 24‐36 kV, 2‐10 mm juice depth, and 2‐10 min treatment time using log‐linear, Weibull distribution, and logistic models. The Weibull and logistic model explained enzyme inactivation kinetics well based on goodness of fit (Coefficient of determination: 0.97‐0.99 & root mean square error: 0.11‐2.15) and validation indices (accuracy factor: 1‐1.06 and bias factor: 0.96‐1.04). The logistic model suited PPO and POD inactivation curves well, with the least Akaike weight in 71.29% and 61.45%, respectively. POD had a half‐maximal activity of 11.37, 5.22, and 3.60 min at 24 kV, 30 kV, and 36 kV at 6 mm juice depth, compared to 8.71, 4.41, and 2.51 min for PPO. This shows that POD is more CP‐resistant than PPO, making its inactivation in kiwifruit juice crucial. Practical Application Kinetic modeling helps to comprehend the fundamental process and is suitable for improving the inactivation process and enhancing its efficacy. As a relatively primary method, mathematical models facilitate a greater comprehension of the mechanism and factors influencing the inactivation processes. This study involves the inactivation of PPO and POD to produce a stable kiwifruit juice. The inactivation of PPO and POD enzymes will prevent the undesirable enzymatic browning of juice. The kinetic data related to enzyme inactivation will help in deciding the process parameters like plasma voltage, juice depth, and treatment time for producing enzymatically stable kiwifruit juice.