Novel gaseous chlorine dioxide treatment system for improving the safety and quality of table grapes during cold storage

Abstract

This study focused on the development of a gaseous ClO2 treatment system that contained dry ice that was used to form carbon dioxide (CO2) and an absorbent pad with sodium chlorite (NaClO2) solution for ClO2 gas generation. Furthermore, the effects of ClO2 gas on the populations of Listeria monocytogenes and the quality properties of table grapes during cold storage were evaluated. The system continuously released the sufficient concentrations of ClO2 gas to treat berries during 30 d of cold storage. After 20 h of ClO2 gas treatment, the populations of Listeria monocytogenes decreased from 5.88 log CFU/g to a non-detectable (ND) level. There were no significant (p > 0.05) changes in the color parameters (L*, a*, and b*) of table grapes treated with ClO2 gas. The firmness, weight, total soluble solids (TSS), and titratable acid (TA) losses of table grapes were significantly (p < 0.05) reduced by ClO2 gas, while Vitamin C was unaffected. Additionally, the residual ClO2 of table grapes were <0.5 mg/kg, which is considered a safe level. Overall, the novel gaseous ClO2 treatment system may be used as an effective intervention technology to improve the safety and quality of table grapes during cold storage.