Effect of cold plasma treatment on sterilizing rate and quality of kiwi turbid juice

Abstract Previous studies have shown that cold plasma inactivated microorganisms located on a variety of food surfaces and food packaging materials under atmospheric pressure conditions; however, less attention has been paid to the impact of cold plasma on microorganisms in liquid food stuffs. The aim of the study is to evaluate the effect of cold plasma treatment on maintaining quality and the bactericidal effect of kiwi turbid juice, and obtain the optimal parameters. Kiwi turbid juice was treated with different treatment voltages, juice volumes, and discharge times. Tow principle components (chlorophyll and total phenols) were extracted by factor analysis and the cumulative contribution achieved was 87.017%. Three‐factor response surface methodology was used to analyze the interactions between the factors, and particle swarm optimization was used to search for the optimal parameters. The results showed that the established three‐index regression model was significant. At the optimal level of 12 kV treatment voltage, 18 ml juice volume, and 1 min discharge time, chlorophyll, total phenols, and bactericidal rate of the optimized test were 0.18 mg/g, 3.47 OD 280 /g, and 83.97%, respectively. This study provides key implications for applying cold plasma during kiwi turbid juice processing. Practical applications Kiwi turbid juice is rich in nutrition, has high quality and good taste, which can greatly retain the flavor of fresh juice, and has a broad market development prospect. Sterilization is a key process in the production of kiwi turbid juice, Cold plasma processing is a potential nonthermal method which can enable extension of shelf life of kiwi turbid juice, yet retaining its freshness and organoleptic properties.