Effect of electric and electromagnetic fields treatments combined with modified atmosphere package on the storage quality of fresh-cut cucumbers (Cucumis sativus L.)

Fresh-cut cucumber (FCC), as one of the most important raw material in vegetable salads, is highly susceptible to quality problems during storage. High voltage electrostatic field (HVEF), as a non-thermal, low energy consumption, and residue free physical field technology, can effectively control the microbial content in food. Electromagnetic fields (EMF) have also been found to have significant effects on microbial proliferation. In this study, a combination of HVEF and EMF was used to treat FCCs in modified atmosphere packaging (MAP) and their storage quality was monitored. It was found that the combination of HVEF and EMF treatment under appropriate parameter conditions can significantly reduce the initial microbial content in FCCs, from 3.71 Log CFU/g to <2.30 Log CFU/g, without having a negative impact on the original cell structure and enzyme system. Combined with MAP, it can effectively reduce the damage to the cell structure of FCCs during storage, thereby reducing weight loss rate and delaying the changes in pH, conductivity, and total soluble solid content during storage. In addition, delaying the changes in peroxidase, polyphenol oxidase and lipoxygenase enzyme activity could also reduce the generation of malondialdehyde and the membrane lipid oxidation and structural damage it brings, reduce the loss of chlorophyll, ascorbic acid, and phenolic substances, and ultimately maintain the sensory characteristics of cucumber slices such as color, texture, appearance, and flavor. Compared with the control group (6 days), the combination of HVEF and EMF treatment with MAP can effectively extend the shelf life of FCCs to 9–12 days.