Untargeted metabolomic analysis of strawberries exposed to pulsed electric fields and cold plasma before postharvest storage

Abstract

After being harvested, strawberries experience a decline in nutrients and anthocyanins, which is further exacerbated by their vulnerability to plant pathogen-related decay. As postharvest losses encompass up to 50 % of total production, the development of a physical method complementary to refrigeration to reduce these losses is a goal pursued globally, given a global market of US$19 B per year. In this study, two non-thermal technologies, pulsed electric fields (PEF) and cold plasma (CP), were used to evaluate their effectiveness in maintaining phytochemical integrity in exposed strawberries. A PEF treatment of 1 pulse at 1 kV/cm field strength in 3 L of tap water could significantly alter the volatile and metabolomic composition of the fruit, while simultaneously reducing its firmness during cold storage. However, subjecting the fruit to a CP treatment at 15 % (210 watts) for 1 min did not impact the quality parameters. Furthermore, unlike the PEF treatment, the strawberries retained their firmness during storage and exhibited a consistent volatile and metabolomic profile. Based on these results, CP treatment enhances firmness and maintains the compounds found in strawberries, meanwhile, while PEF treatment might not be ideal for preserving the physicochemical parameters of fruit