Postharvest application of chitosan and Thymus essential oil increase quality of the table grape cv. ‘Shahroudi’

Abstract

Purpose: Chitosan, a natural biopolymer with antifungal and eliciting properties is able to reduce postharvest decay of table grapes. Anti-fungal and anti-microbial effects of essential oils are the result of many compounds acting synergistically. In this study, the effectiveness of Thymus essential oil (TEO) and chitosan to control postharvest decay and quality of ‘Shahroudi’ table grape was investigated. Research Method: Grapes treated by 0.5% and 1% (w/v) solution of chitosan, 150 and 300 µl l-1 Thymus essential oil and their combination (untreated fruit were as control). At first chitosan solution prepared then Thymus essential oil was added it in combination solution. Harvested grapes were packed in 200g bags and stored at 0±2 ◦C and 90% ± 5 RH for 90 days. Findings: Differences in weight loss, color change, ripening, sensory quality and decay between grapes treated with chitosan and TEO and control fruit suggested that TEO and chitosan were both suitable coatings. Moreover, the sensory analyses revealed beneficial effects in terms of delaying rachis browning and dehydration and maintenance of the visual characteristics of the grape without detrimental effects on taste or flavors. Research limitations: It had no limitation to report. Originality/Value: TEO and chitosan might have good effects in reducing postharvest fungal rot and maintaining the quality of ‘Shahroudi’ table grapes which proved to be much more effective than TEO.