Physicochemical and Physiological Properties of Okra [Abelmoschus esculentus (L.) Moench] Fruits Coated with Polysaccharide-Based Edible Coatings

Abstract

Okra is highly perishable due to its high respiration rate and high-water content, thus reducing its marketability. Hence, this study was conducted to evaluate the effect of different polysaccharide-based edible coatings on the physicochemical and physiological properties of okra fruits. The experiment was laid out in a completely randomized design with nine treatments and three replications. Four edible coatings were assessed at two different concentrations. The treatments comprised T0: uncoated (control), T1: 1% sodium alginate (AL), T2: 2% sodium alginate, T3: 1% pectin, T4: 2% pectin, T5: 1% carboxymethyl cellulose, T6: 2% carboxymethyl cellulose, T7: 1% cornstarch and T8: 2% cornstarch. Okra fruits were stored in refrigerated conditions with the temperature ranging from 9 to 11 °C and relative humidity of 76 to 85%. Samples were collected on days 0, 3, 6, 9, 12 and 15 for analysis of weight loss, firmness, shriveling, pH, total soluble solids (TSS), titratable acidity (TA), vitamin C, respiration rate, ethylene production and microbial growth. The results indicated that the use of polysaccharide-based edible coatings significantly influenced moisture and dry matter content, weight loss, firmness, shriveling, pH, TSS, TA, vitamin C, respiration and microbial count of okra fruits. The various coatings, including alginate, pectin, carboxymethyl cellulose and cornstarch, significantly preserved the quality of okra compared with the control treatment. Among the four coatings used, 2% alginate (w/v) demonstrated the most effective preservation of the fruit quality of okra.