Oligogalacturonides reduced postharvest losses by alleviating mechanical damage in Goji berry (Lycium barbarum Miller)

Goji berry ( Lycium barbarum ) is a typical berry with a tender and thin pericarp, high moisture content and hollow interior, making it highly susceptible to mechanical damage caused by harvest and transportation. As a consequence, this susceptibility results in considerable economic losses within the fresh produce industry due to the degradation of fruit quality and subsequent decay. Here, oligogalacturonides (OGs), a well-characterized plant damage-associated molecular pattern, were applied to reduce postharvest loss and extend the shelf life of berries of the goji cultivar NingQi1. The loss rate in the OGs treatment was 44.45 % lower than that in the 0.8 mm compression treatments on Day 6, and the OGs treatment also effectively inhibited softening and delayed weight loss. The activity of superoxide dismutase increased by 27.4 % on the 4th day after OGs treatment, accompanied by a decrease in malondialdehyde content ranging from 14.2 % to 24.8 % on days 2 to 4 compared to the control group. Furthermore, the phenylalanine ammonia-lyase activity of OGs-treated goji berries was 57.0 % higher than that of the control at 6th days, which slowed the reduction in secondary metabolites such as total flavonoids. The findings of this study indicated that OGs may reduce postharvest losses caused by mechanical damage, extend the shelf life of goji berry by reducing softening and weight loss, and reduce wounding injury by minimizing free radical form of reactive oxygen species.