Maintaining Quality Properties of Grape CV. ‘Bidaneh Ghermez’ by Chitosan Edible Coating, Thymus Essential Oil and theirConcomitant Application

The application of edible coatings is one of the most innovative methods to extend the commercial shelf-life of fruits and vegetables by acting as a gas barrier. In this study, the effects of chitosan, thymus essential oil and their combination in extending shelf life of grape (‘Bidaneh Ghermez’) and quality properties were investigated. Grapes were harvested when were fully ripened and their total soluble solid (TSS) was about 25% and immediately transferred to laboratory. Then fruit treated by 0.5% and 1% (w/v) solution of chitosan, 150 and 300 µl/l thymus essential oil and their combination (untreated fruit were as control). After treatments, grapes were packed in 200g packages and stored at 0-2 ºC and 90% ± 5 RH for 60 days. Changes in weight loss, color, pH, TSS, decay and sensory quality were measured in ten-day intervals until 60 days after the treatments. Results showed that chitosan and essential oil treatment significantly decreased weight loss, decay, color change, shrivel and berry shatter in comparison to the control. According to the panelists’ votes, treated fruits did not show significant difference to the non-treated control fruits. It seems that among different treatments examined, the combined treatment of chitosan and thymus essential oil was more suitable for maintaining the fruit quality.