view:11751 Last Update: 2021-10-13
Sanaz Molaei, Vali Rabiei, Ali Soleimani, Farhang Razavi
Exogenous application of glycine betaine increases the chilling tolerance of pomegranate fruits cv. Malase Saveh during cold storage
Abstract This study was conducted to investigate the effect of exogenous glycine betaine (GB; 0, 10, and 20 mM) treatment on chilling injury (CI) and preserve nutritional quality of pomegranate fruit during 90 days of cold storage at 4°C and 85%–90% relative humidity plus three days of shelf life at 20°C. According to results, the exogenous application of GB, especially at 20 mM, alleviated CI symptoms, enhanced endogenous GB and proline contents, and maintained electrolyte leakage and malondialdehyde contents at low levels. Furthermore, this treatment enhanced the activities of DPPH radical-scavenging and antioxidant enzymes, namely superoxide dismutase, catalase, and ascorbate peroxidase. It also preserved the ascorbic acid content. High levels of total phenols, flavonoids, and anthocyanin were observed in GB-treated pomegranate fruits, as a result of a higher activity of phenylalanine ammonia-lyase and a low activity of polyphenol oxidase. In conclusion, an optimal concentration of exogenous GB as natural and safe treatment could alleviate the CI and preserve postharvest quality of pomegranate fruits during cold storage period. Practical applications Usage of long-term cold storage is an efficient and well-known method for preserving postharvest quality of various fruits and vegetables. However, in some crops especially those belongs to tropical and subtropical climates, storing in cold storage leads to different limitations such as CI. Therefore, application of postharvest strategies to enhance tolerance of low temperature stress and decrease injuries is suggested. Based on current results, exogenous GB treatment could be efficient in reduction of CI symptoms and preserve nutritional quality of pomegranate fruit over the cold storage period.