optimization of polysaccharide based active coatings for prolonging the shelf life of red delouses apple by response surface methodology

in the present study, optimization of active-blend coating formulation was investigated by response surface methodology (rsm). for this purpose, central composite design with four variables (concentration of carboxymethyl cellulose-pectin, ascorbic acid-citric acid, potassium sorbate and butylated hydroxyanisole ) were used. weight loss is selected as responses of model. on the base of minimum weight loss, optimum coating solution was determined. effects of coating solutions on quality attributes of apples were studied. the coated apples lost their 1.23% weight, while uncoated ones lost of 5% their weight (p < 0.05). the results of firmness test showed that coating of apple caused to maintain of initial texture. the acidity values of coated apples were significantly higher than uncoated samples after 40 days at 5-6 °c. there is no significant difference in brix among coated and uncoated apples. the using of coatings resulted to reduce yeast and mold count in coated apple (1.6 log cfu/ml) compared to uncoated sample (2.7 log cfu/ml).  sensory evaluation was also satisfactory