Effects of Calyx Coating and Storage Temperature on Antioxidant Substances of Cape Gooseberry (Physalis peruviana L.)

Cape gooseberry is a climacteric, temperature-sensitive fruit from the Solanaceae family. Its quality and quantity are characterized by phenolic and antioxidant substances, the stability of which depends on temperature and storage conditions. In this research, the effects of calyx cover (fruits without calyx cover and fruits covered with calyx) and storage conditions were evaluated on the storage life of Cape gooseberry fruits. For this purpose, the fruits were kept in with and without calyx conditions at three temperature levels of 10, 15, and 20 °C for 30 days. The results showed that, at the end of storage, the titratable acidity, total soluble solids, vitamin C, total flavonoid, and total antioxidants decreased significantly. However, total phenol content and flavor index increased during the storage period. The increase in total flavor and phenol content during storage can be due to a significant reduction in the titratable acidity (as reflected in the flavor index), because of cellular destruction and cold damage. In addition, at the end of the storage period, the calyx-covered fruits which were stored at 10 °C had good physicochemical and antioxidant qualities. The highest titratable acidity (0.633%), soluble solids (14.96%), vitamin C, and total antioxidants (59.33%) were observed in fruits covered with calyx at 10 °C. Also, the results of this study showed that storing berries at cooler temperatures increased the shelf life and maintained the quality of the Cape gooseberry.