Indirect treatment of plasma-processed air to decrease decay and microbiota of strawberry fruit caused by mechanical damage

Abstract

Due to the soft texture of strawberry fruit, it is highly susceptible to mechanical damage during postharvest supply chains, resulting in decay and quality deterioration. Urgent investigation is needed on the treatment techniques to mitigate the impact of postharvest mechanical damage of strawberry fruit. In the present study, the effect of indirect plasma-processed air (PPA) pretreatment to decrease decay and microbiota of strawberry fruit caused by mechanical damage was investigated. The results show PPA pretreatment reduced the total counts of indigenous microbiota on the surface of intact and mechanical damaged strawberry fruit by 4.29 and 3.76 log10CFU/g at day 0, respectively, and reduced the counts of S. aureus and E. coli inoculated on strawberry fruit by 3.05–3.16 and 3.55–3.56 log10CFU/g, respectively. The disease incidence of fruit inoculated with Botrytis cinerea was also decreased by 6.67 %–18.89 % during storage. Besides, PPA pretreatment reduced the decay rate of strawberry fruit by 5.56 %–21.11 % during storage and did not significantly affect the firmness, color index of red grapes (CIRG) and total soluble solids (TSS) content of strawberry fruit. DHHP results indicate that the antioxidant activity of the strawberry fruit was increased. After PPA pretreatment, 39 metabolites were differentially accumulated in strawberry fruits, 37 of which were up-regulated, including flavonoids, phenolic acids and organic acid.