Effects of storage temperature on postharvest quality of wild plum (Ximenia americana L.)

Abstract

Wild plum (Ximenia americana L.) is a tropical crop widespread throughout the tropics of Africa, India and South East Asia to Australia, New Zealand, Pacific Islands, West Indies, Central and South America. Despite the widespread distribution of wild plum, it remains unexploited and it has potential for commercial exploitation. Wild plum has many medicinal, therapeutic, nutritional and energy uses, but its products are collected in the wild and less researched. A laboratory experiment was undertaken to evaluate the effects of storage temperature on postharvest quality and shelf-life of wild plum fruits. The treatments were storage temperatures at 0, 5, 10 and 15 ± 1“C laid down in a completely randomized experimental design. The results of the study showed that storage temperature significantly (P < 0.05) influenced chilling injury incidence and severity of wild plum fruits. As storage temperature decreased below I5°C, the incidence and severity of chilling significantly (P < 0.05) increased. Storage temperature also significantly (P < 0.05) influenced wild plum fruit quality attributes such as titratable acidity, juice pH, soluble solids content, vitamin C content, weight loss and shelf-life. As storage temperature increased from 0 to 15"C fruit titratable ucidity and vitamin C content significantly (P < 0.05) decreased, while juice pH, soluble solids content and weight loss significantly (P < 0.05) increased. The decrease in fruit titratable acidity and vitamin C content, plus the increase in soluble solids content and juice pH was attributed to fruit ripening. The increase in fruit weight loss with increase in storage temperature was attributed to higher transpiration and respiration rates at the higher temperatures. Storage of wild plum fruit at 15’C maintained fruit quality and fruit had a shelf­ life of twenty eight days, instead of two days or less at other temperatures in this study due to chilling injury. Therefore, it was concluded that in order to extend the shelf-life and marketing period of wild plum fruits, the fruits should be stored at 15’C and 90-95% RH.