RSM-Based Optimization of Edible-Coating Formulations for Preserving Post-Harvest Quality and Enhancing Storability of Phalsa (Grewia asiaticaL.)

Abstract

The fruit of Grewia asiatica L., which is locally known as “phalsa,” contains high amounts of phenolics and anthocyanins. However, because of its perishable nature, this fruit remains underutilized. Hence, it becomes necessary to employ ways that will extend the shelf life of this fruit until it reaches the consumers. Application of edible coatings provides a cheaper and easy method to protect horticulture products during postharvest handling. Response surface methodology was used to optimize the concentrations of edible-coating formulation comprising of Soy Protein Isolate (SPI), Olive oil, Hydroxy Propyl Methyl Cellulose (HPMC) and Potassium Sorbate. The study suggested SPI 3.45%, HPMC 0.40%, olive oil 1% and potassium sorbate 0.25% to be the most suitable for phalsa. Three optimized coating emulsions, including the above suggested emulsion, were selected for further biochemical studies of phalsa. The results obtained from this study revealed that the optimized coatings could successfully retain the quality attributes of phalsa. Practical Applications Edible coatings on fresh fruits can provide an alternative for modified atmosphere storage by reducing quality changes and quantity losses during their postharvest storage. The composition and concentration of edible coatings plays a major role in this process. The present study used response surface methodology (RSM) to optimize the concentrations of soy protein isolate, hydroxy propyl methyl cellulose, olive oil and potassium sorbate in edible coatings for phalsa. The results of present investigation offer suggestions for possible formulation of composite edible coating that can be used for enhancing the postharvest quality and shelf life of phalsa. Because the study is based on RSM optimization of edible-coating formulations, it helps predict the exact concentration of each component of a coating emulsion and its effect on the physiology of the fruit. This can help to formulate edible coatings on commercial basis, in the long run.