Pre-harvest application of chitosan and Aloe vera gel coating on biochemical ‎parameters and post-harvest life of ‘Asgari’ grapes

The use of biodegradable films and edible coatings with antimicrobial properties as a suitable alternative to synthetic preservatives is important in order to maintain food security and prevent capital wastage. In this respect, the effect of pre-harvest chitosan spraying (at three concentrations of 0, 2 and 3%) and post-harvest immerging in Aloe vera gel (25 and 33%) on the quality and shelf life of ‘Asgari’ grape fruit in five different times (0, 7, 14, 21 and 28 days after harvest) at 4 °C was evaluated. The results showed that berries treated with chitosan and Aloe vera gel contained higher content of vitamin C, soluble solids, Total flavonoids content, peroxidase activity and shelf life and lower content of malondealdehide (MDA) than the control, as well as, polyphenol oxidase enzyme activity and weight loss percentage were lower in fruits treated with chitosan and aloe vera gel.The highest amount of vitamin C, soluble solids and peroxidase activity in all five measurements belonged to the combined treatments of chitosan 2% and Aloe gel 25% and the highest flavonoid content and fruit shelf life was observed in the treatment of chitosan 3% with Aloe gel 25%. In all five measurements, it was observed that 2% chitosan treatment with 25% Aloe gel had the lowest weight loss, polyphenol oxidase activity and MDA.