Conductive hydro drying of ripened papaya: optimization and product characterization.

This study addresses the product-process characterization of refractance window drying of ripened papaya, considering the abundant availability and underutilization of the perishable product. A statistical design approach with varied drying temperature, time and sample thickness has been adopted to characterize moisture content, total phenolic content, total flavonoid content, vitamin C, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The model fitting, analysis of variance, and numerical optimization showed that the quadratic model was the most suitable model for the response variables. The optimum process parameters were attained at a drying temperature of 90 °C, time 86.92 min, and sample thickness of 2.93 mm. The optimal responses were moisture content 2.81%, total phenolic content 305.58 mg GAE/g, total flavonoid content 51.92 mg QUE/g, DPPH radical scavenging activity 91.56% and vitamin C 219.88 mg/100 g. With such high essential nutrients, refractance window dried ripened papaya can be utilized for commercially viable value-added food products.