Maturity and post-harvest studies in mango (Mangifera indica Linn.)

Abstract

The present investigations were carried out in the College of Horticulture, during the year 1979-80. The objectives were to study (i) the growth and maturity of mango fruits in order to standardise the harvest indices in five varieties viz., Bennet Alphonso, Mundappa, Suwarnarekha, Olour and Neelum (ii) the effect of different storage methods on the shelf life of fruits harvested at three different stages (A,B and C) and (iii) the suitability of the varieties for canning. Studies on physic-chemical characters of the fruits throughout the period of maturation were conducted with the view to fix optimum time for harvest. This study brought out that the length, weight, specific gravity (except for Mundappa) reducing sugar, starch and T.S.S. contents could be taken as dependable maturity standard. Based on these parameters the maturity standards have been fixed for the five varieties studied. The growth of fruits by way of increased length, girth, weight and volume was maximum during the first four weeks of maturation. From a stage to full maturity the acidity showed a declining trend while starch content increased. The change in reducing sugar content was erratic throughout the period of maturation. Towards full maturity the moisture and ascorbic acid contents showed gradual decline whereas an increasing trend was observed in case of drymatter content. As maturity advanced, the rate of increase in carotene content also increased. To prolong the shelf life, the most effective method was to store fruits in polythene bags of 300 gauge thickness along with KMnO4 which gave a mean storage life of 25.5 days. Storage in 300 gauge polythene bags alone was also equally good. The more the thickness of polythene, the longer was the shelf life. Waxing of fruits was not be effective as storing fruits in 300 and 250 gauges polythene bags, in terms of shelf life, but the extent of reduction in weight at the end of storage life was least in this method. Waxing was also effective in retention of acidity as well as ascorbic acid content during storage. In this method the total sugar content of the ripe fruits was not appreciably affected compared to other methods except control. The waxed fruits on ripening had the same extent of increase in carotene content as those under the other methods. Waxed fruits at the end of storage period had significant increase in T.S.S. content as compared to storage in polythene bags 250 and 300 gauges as well as in polythene bags 300 gauges along with waxing or KMnO4 . Storage of fruits in polythene bags of 300 gauge thickness, at the end of storage period, resulted in reduction of acidity and T.S.S. content compared to waxing. Compared to the untreated fruits, there was more retention of ascorbic acid content in this method. In terms of storage life as well as quality of fruits at ripening, the best stage for harvest was found to be B stage. Among the five varieties studied Bennet Alphonso and Neelum had better storage life followed by Mundappa, Suwarnarekha and Olour respectively. The quality of ripe fruits varied with varieties. In terms of storage life as well as quality of fruits Neelum came best. In shelf life though Bennet Alphonso came second, in quality of ripe fruits Mundappa was the second best. Neelum was found to be most suitable variety for canning followed by Mundappa. Bennet Alpphonso was the least suitable.