EFFECTS OF EDIBLE SURFACE COATINGS (SODIUM CARBOXYMETHYL CELLULOSE, SODIUM CASEINATE AND GLYCEROL) ON STORAGE QUALITY OF BERANGAN BANANA (MUSA SAPIENTUM CV. BERANGAN) USING RESPONSE SURFACE METHODOLOGY

Response surface methodology was used to predict the effects and to optimize the concentration of sodium carboxymethyl cellulose (0.1–1.5% w/w), sodium caseinate (0–1% w/w) and glycerol (0–2% w/w) on storage quality of coated Berangan banana (Musa sapientum cv. Berangan). The experimental data could be adequately fitted into a second-order polynomial model with multiple regression coefficients (R2) of 0.787, 0.704, 0.933, 0.786 and 0.886 for the weight loss, firmness, total color difference, total soluble solids content and titratable acidity of coated banana, respectively. The optimum concentrations of sodium carboxymethyl cellulose, sodium caseinate and glycerol for coating banana were predicted to be 1.32, 0.40 and 0.86%, respectively. In general, the sodium caseinate content appeared to be the most significant factor influencing all characteristics of coated banana studied at 26±2C and 40–50% relative humidity. No significant difference between experimental and predicted values verified the accuracy of the response surface models employed. PRACTICAL APPLICATIONS Edible coatings create a modified atmosphere within the fruits and delay their ripening process. Type and concentration of edible coating components contributed in determining the quality (changes in physicochemical characteristics) of coated Berangan banana. Protein and polysaccharide coatings have excellent barrier properties against O2 and CO2. Small amount of additive such as plastisizers like glycerol can improve the appearance of coated fruit and mechanical property of the edible coating. Due to the hydrophobic nature of banana cuticle, addition of emulsifiers such as sodium caseinate can enhance the homogeneity of the edible coating on the banana skin. Therefore, composite edible coatings can successfully be employed as a means to improve the barrier characteristics of edible coatings covering the banana and hence extend its shelf life.