Physiological and biochemical attributes associated with jelly-seed disorder in mango (Mangifera indica L.)

‘Jelly-seed’ is considered as a serious disorder of mango which causes considerable postharvest losses. Due to the lack of clear understanding of jelly-seed disorder genesis and minuscule research work, a study was carried out to know the physiological and biochemical basis leading to the incidence of the jelly-seed disorder in ‘Langra’ and ‘Dashehari’ mango varieties. The results revealed that the respiration rate (143.32 and 149.32 mg kg−1 h−1 CO2) in the jelly-seed affected fruits was higher than the healthy fruits of both the varieties, while the ethylene evolution rate showed no significant difference. The biochemical attributes such as β-carotene (1.28 and 1.64 g kg−1) and total antioxidant capacity (607.78 and 563.25 mmol kg−1 Trolox) of jelly-seed affected pulp was significantly lower than the healthy pulp (HP) and pulp surrounding affected pulp (PSAP) in both the varieties, respectively. Ascorbic acid (66.76 and 33.70 g kg−1), TSS, reducing sugars (9.34 and 8.49%), total sugars and titratable acidity have been recorded to be higher in the jelly-seed affected pulp (AP) in both the varieties, respectively. This may be due to the higher activities of α-amylase (0.99 and 1.21 g kg−1 h−1 maltose liberated), pectin methylesterase (0.30 and 0.30 mmol min−1 kg−1 acid) and cellulase (0.0487 and 0.0564 U g−1) enzymes in the jelly-seed AP in both the varieties, respectively. Polyphenol oxidase enzyme activity was also significantly higher in jelly-seed affected pulp of both the varieties. The results of respiration rate suggested that the jelly-seed malady in mango may be a result of high seed activity rather than fruit pulp activity because the mesocarp tissue surrounding the vicinity of the seed is totally disintegrated and the seed might have entered into premature seed germination mode (vivipary nature). The affected fruits showed a higher respiration rate, reduced β-carotene content and total antioxidant capacity leading to loss of nutritional value.