Fruit firmness is an important factor which highly effects
the fruit quality. Various fruit coatings significantly
affected the fruit firmness as compared to control.
Results revealed that fruit firmness was decreased in all
the treatments with the advancement of storage period, but
at the end of storage period maximum fruit firmness was
retained by the fruits coated with Carboxymethyl cellulose
@ 0.25%. Whereas minimum fruit firmness was recorded
in the control (untreated) fruits (Fig.1). The decrease in
fruit firmness during prolonged storage may be attributed
to increased rate of respiration and consequently enhanced
fruit ripening. However, rapid loss in firmness during
storage might be associated with the increased activity of
polygalacturonase (PG), pectin methyl esterase (PME) as
well as depolymerization of cell wall pectins (Bartley et
al., 1982). The effect of coatings to retard the firmness
loss is due to its role in checking the activity of cell wall
enzymes. It might also be attributed to change in the turgor
of the cells and changes in the composition of cell wall
pectin and lipo protein membrane bordering the cells
(Chen et al., 1991). Juice pH determines the acid content
of fruit juice and attributes to the juice quality. Juice pH
showed the inconsistence during storage. All the fruit
coatings significantly effected the change in juice pH.