Edible Coatings for Lightly Processed Fruits and Vegetables

Abstract

Minimal processing is defined as handling, preparation, and distribution of agricultural commodities in a fresh state. Cutting fresh produce results in injury, cell leakage and accelerated perishability. The presence of an artificial barrier to gas and moisture diffusion ideally would reduce moisture loss, decrease levels of internal oxygen, increase internal carbon dioxide, reduce respiration rate and wound ethylene production, and delay ripening/senescence. In practice, the degree to which the above factors can be altered for a given commodity depends on species, cultivar, surface-to-volume ratio, respiration rate, etc. An edible coating, as an artificial barrier, is made from renewable resources, is biodegradable and can be used as a carrier for antioxidants, artificial colors, flavors, growth regulators, enzyme inhibitors and preservatives. The cutting of produce, however, results in a high moisture surface which presents special problems for coating adherence and microbial control. Recent research on coating of cut mushrooms, celery, apples, pears and peeled carrots, to maintain texture and reduce discoloration, with edible composite coatings will be discussed.