Edible coatings from morpholine-free wax microemulsions.

摘要

Edible wax coatings were made by the drying of wax microemulsions composed of water, fatty acid, ammonia, and various combinations of candelilla wax, beeswax, carnauba wax, polyethylene wax, and petroleum wax. The properties of the wax coatings, andtheir performance on Valencia oranges stored at 23deg C and 60% RH, were studied. All 19 coating formulations studied were effective moisture barriers, limiting weight loss of oranges, with the best being those containing candelilla wax, beeswax, and petroleum wax. Polyethylene and carnauba wax coatings had the best gloss, but also were the most brittle. Emulsion clarity was improved by using some myristic or palmitic acid, rather than commercial grade oleic acid as the only source of fatty acid. Comparedwith wax coatings made with ammonia-based emulsions, those made with morpholine had higher permeability to oxygen and water vapour, possibly because the morpholine, being less volatile than ammonia, stayed longer in the coating.