Effect of Chitosan Coatings Enriched with Lauroyl Arginate Ethyl and Montmorillonite on Microbial Growth and Quality Maintenance of Minimally Processed Table Grapes (Vitis vinifera L. Kyoho) During Cold Storage

The effects of lauroyl arginate ethyl (LAE), chitosan (CTS), and CTS-containing montmorillonite and LAE coatings (CML) on the quality maintenance and shelf life of minimally processed grapes stored at 4 °C for 20 days were investigated. Compared with the control, LAE, and pure CTS coatings, the CML coatings effectively decreased grape weight loss, respiration, and decay incidence as well as microorganism counts of total aerobic bacteria, yeasts, molds, and lactic acid bacteria in grapes. The CML coatings also showed better effects on delaying the tissue softening and browning due to the decreased activities of polygalacturonase, pectin methyl esterase, and polyphenol oxidase. CML coatings did not significantly change the content of soluble solids and the titratable acidity or the pH value of grapes, compared with other samples. However, CML coatings ensured higher content of ascorbic acid and sensory quality in grapes. The results confirmed that CML coatings improve microbiological safety and preserve nutritional and sensory quality of minimally processed grapes.