Impact of Cold Plasma Treatment on the Shelf Life and Metabolite Profiles of Strawberries during Storage.

Abstract

Strawberries are abundant in bioactive compounds and serve as a significant source of ascorbic acid. However, their shelf life is notoriously short due to their high sensitivity to environmental conditions and susceptibility to microbial contamination. The growing demand for ready-to-eat products among consumers presents challenges related to food preservation, especially with increasing food losses due to microbial spoilage. Various strategies have been explored to address these issues, one of which is atmospheric cold plasma. A surface dielectric barrier discharge cold plasma (CP) treatment was applied to fresh strawberries (output voltage: 6 kV, frequency: 23 kHz) for 30 min. Spoilage microbial populations, quality, and primary and secondary metabolite profiles were evaluated during storage at 4 °C. Cold plasma treatment resulted in significant reductions in the counts of the main spoilage microbial groups, which showed delayed and limited growth compared to the untreated fruits. LC-MS/MS analysis revealed the preservation of the total phenolic profile, along with a significant increase in total phenolic acids (from 614.2 to 784.4 mg/kg) and total flavonols (from 145.2 to 196.4 mg/kg) immediately after treatment. An increase in the levels of specific polyphenols and antioxidant activity was observed. Although ascorbic acid decreased after treatment, greater stability was noted during storage. In conclusion, CP can preserve fruit quality and extend the shelf life of fresh strawberries without adversely affecting their physical properties.