Effects of chitosan coating on postharvest life and quality of guava (Psidium guajava L.) fruit during cold storage

The effect of chitosan coating on physiochemical characteristics of 'pearl' guava fruit was investigated. The fruit were treated with 0.5, 1.0 and 2.0% chitosan coatings, respectively, and then stored at 11 C and 90-95% RH. Treatment with 2.0% chitosan significantly reduced firmness and weight loss, delayed changes in chlorophyll and malondialdehyde (MDA) contents and soluble solids content (SSC), and retarded the loss of titratable acidity (TA) and vitamin C during 12 days of storage. This treatment could induce a significant increase in the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), and inhibited superoxide free radical (O-2(center dot-)) production. It was suggested that effects of chitosan on increase of antioxidant ability might be beneficial in delaying ripening process in guava fruit during cold storage. (C) 2012 Elsevier B.V. All rights reserved.