New strategy for improving postharvest quality of cherry tomatoes: Synergy of plasma-activated water and Welsh onion leaf protein extracts

Plasma-activated water (PAW) has significant advantages in inactivating a variety of microorganisms, which is increasingly being used in combination with other technologies (ultrasound, mild heat, and antimicrobial agents, etc.) in food decontamination studies, especially for fresh fruits and vegetables. Nevertheless, studies have yet to be on combining PAW with plant protein extracts for fruit preservation. To improve the decontamination effect of PAW, we extracted an antimicrobial protein, the effects of adding 5% Welsh onion leaf protein extract (WOLPE) on microbial growth, physicochemical properties, nutritional composition, antioxidant capacity, microstructure, and sensory quality of cherry tomatoes treated with PAW were investigated. The results of 14 d storage at 4 °C showed that PAW combined with WOLPE (PCW) treatment reduced the microbial counts by 2.11 log CFU/g and 3.99 log CFU/g for bacteria and fungi, respectively, as compared to the control group treated with sterile deionized water. Firmness and relative electric conductivity (REC) results showed that PCW treatment delayed the softening of cherry tomatoes, while PCW treatment had no negative effects on the color and pH of cherry tomatoes and improved antioxidant capacity. The sensory and nutritional qualities of cherry tomatoes were maintained and the shelf life was extended. The results indicated that PCW technology is a promising method for the postharvest preservation of cherry tomatoes.