In-package cold plasma decontamination of fresh-cut carrots: microbial and quality aspects

Abstract

Abstract Cold plasma is a promising nonthermal technology for the decontamination and preservation of fresh and fresh-cut produce. The rapid action of a cocktail of reactive oxygen and nitrogen species in plasma against a variety of food spoilage and pathogenic organisms make it a suitable decontamination intervention. This study evaluates the effectiveness of high voltage atmospheric cold plasma in reducing the natural microflora of carrots treated at 60, 80, and 100 kV (60 Hz frequency) for 1, 2, 3, 4, and 5 min. About 2 log 10 CFU/g reduction in the population of both, total aerobic mesophiles, and yeast and mold was observed in carrot discs treated at 100 kV for 5 min (~250 W power). The changes in pH, colour, texture, and total carotenoids of cold plasma treated carrots were minor. For shelf-life evaluation of plasma treated cut-carrots voltages between 80 to 100 kV and treatment times between 4 to 5 min is recommended, such that reduction in spoilage microflora and quality retention is maximized. Voltage was found to have a significant effect on the total carotenoids and colour of the carrot discs. Further optimization of the process parameters, preferably using modified gases, is necessary to balance the desired reduction in microflora versus the quality retention.