Safety and quality preservation of starfruit (Averrhoa carambola) at ambient shelf life using synergistic pectin-maltodextrin-sodium chloride edible coating

The demand for fresh, safe, and healthy fruits by consumers has increased, which concurrently occurs with an increase in initiatives on reducing food wastage. Starfruit consists of good nutrition and valuable sensory attributes, but its shelf life is short and can only be preseved for a few days at ambient storage. This research was conducted to determine the effectiveness of synergistic edible coatings (pectin [Pe] and maltodextrin [M] and 100, 200, and 300 ppm of sodium chloride [SC]) on the quality and safety criterion of starfruits throughout a shelf life analysis of 14 days at ambient temperature. Consumer acceptability of the edible-coated starfruit was also evaluated. The coating process was performed using a dipping method. The uncoated (control) and coated samples were evaluated for the characteristics of weight, pH, total soluble solids (TSS), water activity, color, texture, microbial growth, FTIR, and sensory evaluation. From the results, the starfruit coated with Pe + M + 100 ppm SC had a significantly lower weight-loss trend compared to the other samples. On day 14, pH of the coated starfruits were 3.02, 3.14, and 3.31 for 100, 200, and 300 ppm of SC, respectively, were found to be significantly different (p < 0.05) from the control (pH 3.49). The control had a significantly higher value of total soluble solids (6.00 ⁰Brix) compared to the coated starfruits (6.00, 5.47, and 5.33 ⁰Brix, respectively). The coated samples have significantly higher values of firmness than control especially in initial days of storage. It was observed that Pe + M + 100 ppm SC could minimize the spoilage of fruits by reducing the growth of yeast and mold, as well as bacteria, up to 0.86 and 2.02 log CFU/ml, respectively. FTIR results confirmed the presence of the coating on the starfruit. In the sensory evaluation, no significance different (p > 0.05) were obtained for all the sensory attributes and overall acceptability for day 0 and 3. In conclusion, starfruit coated with synergistic Pe + M + 100 ppm SC appeared to be the best sample in extending its shelf life and maintaining the physicochemical characteristics of starfruits up to more than 14 days.