ABSTRACT
Shelf life of ripe fruits, especially of the climacteric type, represents one of the most significant agronomical traits that determine the fruit quality during post-harvest marketing and impacts the economic returns to the producer and seller (Peralta and Spooner, 2006; Paliyath et al., 2009; Nath et al., 2014). Substantial fruit losses occur during the postharvest period largely due to the highly perishable nature of horticultural produce (Kitinoja et al., 2011). The physiological and biochemical changes that transform an unripe fruit to a desirable, edible ripe fruit are also associated with reducing fruit shelf life, increasing shrivelling (water loss), surface cracking, premature senescence and microbial decay, thereby lowering the acceptability of ripe fruits. Significant attention has been paid to the
fruit-softening process as the fruit structure weakens and becomes more susceptible to mechanical bruising and decay symptoms due to post-harvest pathogens. A large number of cell wall hydrolytic and lyase enzymes are produced de novo during fruit ripening, which have been implicated in textural changes and fruit softening. However, jury is still out about their molecular role in fruit texture and softening (Negi and Handa, 2008; Seymour et al., 2012). The ripening-associated changes in fruit membrane also play significant roles in the production of volatile compounds, enhancing the organoleptic characteristics of fruits (Kausch et al., 1997; Palma et al., 2011; Whitaker et al., 2011; Osorio et al., 2013). Membrane integrity was found to be intact during tomato fruit ripening, and it was postulated that changes in the degree to which enzymes are bound to membranes comprise one of the mechanisms by which the activities of enzymes are controlled in tomato pericarp (Mattoo and Vickery, 1977). Interestingly, the alteration of cellular membranes results not only in mixing of cell constituents but also in the loss of cell turgor, making fruits susceptible to post-harvest handling, transit and marketing (Lara et al., 2015).
