Composite coating of chitosan with salicylic acid retards pear fruit softening under cold and supermarket storage

Abstract

Fruit softening is enzyme mediated degradation process determined by the action of cell wall modifying enzymes. Present study evaluated the combined effects of chitosan (CH) and salicylic acid (SA) coatings in modulation of fruit softening enzymes in Punjab Beauty pear (Pyrus pyrifolia × Pyrus communis) fruit stored under cold (0-1 °C and 90-95 % RH) and supermarket (20-22 °C and 80-85 % RH) conditions. Composite CH + SA coatings reduced mass loss and retained fruit firmness throughout the 67 and 20 days storage period. In addition, CH + SA prevented membrane damage by suppressing the electrolyte leakage and malondialdehyde (MDA) accumulation as compared to CH or SA alone. CH 2.0 % + SA 2.0 mM coating efficiently delayed the cell wall degrading enzymatic activities including pectin methylesterase (PME), polygalacturonase (PG) and cellulase associated with fruit softening up to 60 and 15 days storage period in cold and supermarket conditions, respectively.

Keywords: Cell wall hydrolysing enzymes; Cellulase; Fruit softening; Pyrus pyrifolia x Pyrus communis; Storage condition.