Edible coatings composed of methylcellulose, stearic acid, and additives to preserve quality of pear wedges

The ability of methylcellulose and methylcellulose-stearic acid coatings to preserve the quality of Anjou pear wedges stored at 4C and 78% relative humidity over a period of 12 days was assessed. The effect of some additives (ascorbic acid, calcium chloride, and sorbic acid) alone or in combination with the edible coatings was also evaluated. The use of edible coatings and additives prolonged the shelf life of treated samples by retarding browning and enhancing texture when compared to control samples. Methylcellulose-stearic acid coatings played an important role in avoiding weight loss, while methylcellulose-only coatings showed poor water vapor barrier properties. Pear wedges coated with the methylcellulose-stearic acid formulation contained higher amounts of hexyl acetate throughout the storage period, probably due to synthesis by wounded tissue from the stearic acid contained in the coating. No effect from the applied treatments on the titratable acidity, soluble solids content, and microbial load of treated pear wedges was found.