APPLICATION OF A CHITOSAN BASED NANOPARTICLE FORMULATION AS AN EDIBLE COATING FOR TOMATOES (SOLANUM LYCOPERISCUM L.)

The efficacy of chitosan edible coatings in maintaining postharvest quality has been well demonstrated. Further enhancement may be possible by a novel chitosan based nanoparticle formulation capable of allowing better delivery of the chitosan particles into intact fruit tissues due to reduced droplet size. Three nanoparticle formulations of 1% chitosan with different droplet sizes (800, 600 and 400 nm) were prepared by subjection to ultrasonic waves, and applied as an edible coating on tomatoes. The fruits were stored at 15±2°C and 70-80% relative humidity (RH) for 20 days, during which different quality parameters of the fruits were assessed as an indication of the progression of ripening. The indicators of tomato ripening, which include loss of firmness and chlorophyll content as well as increase in soluble solids content and colour evolution from green to red were all found to be delayed in the chitosan treated fruits in comparison to the control (p<0.05). However, weight loss was relatively higher in the treated fruits in comparison to the control. Meanwhile, the 800, 600 and 400 nm treatments were at par (p>0.05). The results demonstrate the potential of this coating for maintaining postharvest quality of fresh fruits like tomato except for weight loss.