Physiological changes in Karanda (Carissa carandus L.) fruit during growth and ripening

Purpose - Increased reliance on major food crops has caused shrinking of the food basket. Therefore, the aim of the present study is to introduce underutilised fruit of Karanda (Carissa carandus L.) for its commercial exploitation. Design/methodology/approach - The present study elucidates the physiological changes that prevail in the fruits of Karanda during its successive stages of growth and ripening. Changes in sugars, starch, proteins, phenols, amino acids, role of various enzymes and rate of ethylene and respiration has been used as parameters to access the physiological changes taking place. Findings - Notable change was observed in its colour from green to deep blue/black, accumulation of sugars and proteins, degradation of starch, phenols and free amino acids. Cell wall degrading enzymes (polygalactouronase and pectin methylesterase) and antioxidant enzymes (catalase and peroxidase) showed their active role, while that of cell wall degrading enzyme cellulase and hydrolyzing enzymes (amylase and invertase) were not active during the growth and ripening of the fruit. Increased levels of respiration and ethylene production determined it to be a climacteric type of fruit. Research limitations/implications - The study does not provide information regarding the other nutritional parameters of the fruits like vitamins and minerals. Originality/value - The physiological changes in relation to growth and ripening would be useful in determining the maturity indices for harvesting and utilization of this underutilised Karanda fruit.