The Effect of Glycine Betaine and Intermittent Heating on Maintaining the Quality and Shelf Life of Sweet Peppers

In order to investigate the effect of glycine- betaine (GB) and intermittent warming (IW). On shelf life and quality of sweet pepper fruits an experiment was conducted as a factorial based on complete randomized design in University of Zanjan in 2016. Treatments were consisted of intermittent warming at three levels (control, 20 and 30 ºC) and glycine- betaine at three levels (0, 5 and 10 mM). The fruits were stored at 4 °C and 85±5% RH for 30 days. The results showed that the amount of vitamin C, chlorophyll, carotenoids content and peroxidase activity in the fruits were decreased and fruit weight loss percentages, extract pH and electrolyte leakage were increased during storage at low temperature (4 °C) by gradually increasing of storage time. Intermittent warming and glycine betaine had positive effects on studied traits such as soluble solids, extract pH, vitamin C, chlorophyll, carotenoids content and peroxidase activity and improved the quality of pepper fruit during storage at low temperatures. These treatments prevented weight loss and electrolyte leakage during the storage. The intermittent warming between temperatures of 20 °C and 5 mM of GB were found to be more beneficial in improving the qualitative characteristics of pepper fruits. Therefore, the use of glycine betaine and intermittent warming can increase quality of sweet pepper, and by preventing the increase of contamination, can be improved the shelf life of sweet pepper.