Postharvest Treatment of Chinese Kale (Brassica oleracea var. alboglabra) by Pulse Light to Removal of Microbial Load, Pesticide Residue and Integrity of Physicochemical Quality and Phytochemical Constituent

Abstract

Existence of microorganisms, pesticide residue on fresh vegetables has a potential hazard to human health. The demand for safe green Chinese kale (Brassica oleracea var. alboglabra) has increased recently. Chinese kale is a healthy botanical attached to the Brassicaceae class. It contains numerous nutritional and phytochemical constituents beneficial for human health. Besides health benefits, this green vegetable also poses food safety concerns due to pathogen and pesticide residue during cultivation. Non-thermal physical technology like pulsed light (PL) will be a promising alternative to eradicate microbial and pesticide residue while preserving the best physicochemical properties and phytochemical components. This research evaluated the influence of different pulsed light intensities (1.2-10.8 J/cm2) on the removal of microbial load and pesticide residue as well as weight attrition, texture hardness, dry matter, vitamin C, total phenolic content in the treated Chinese kale. Results showed that pulsed light intensity 8.4 J/cm2 was appropriate to completely eliminate pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Salmonella; pesticide substances such as carbendazim, abamectin, cypermethrin, chlorpyrifos ethyl, mancozeb. At pulsed light intensity 8.4 J/cm2, weight attrition in the treated sample was lower than weight attrition in the untreated; meanwhile textural hardness, dry matter, ascorbic acid and total phenolic content remained higher in the treated sample compared to the untreated. The results reveals that the pulsed light technique should be applied as a promising decontamination approach for removal of the pathogen as well as pesticide residue with minor impact on physicochemical properties and phytochemical constituents.