Development of osmo-air dried litchi arils from fruits affected with pericarp browning using response surface methodology

Response surface methodology (RSM) was used to optimize the blanching time and sugar concentration of osmo-solution for the preparation of value added osmo-air dried arils from the litchi fruits affected with pericarp browning. Three-level factorial design consisting of two variables (blanching time and sugar strength of osmo solution) with 17 runs was prepared. This design was used to develop models for the yield, acidity and sensory scores of the osmo-air dried litchi arils. Responses were mostly affected by the specific combinations of independent variables. The behavior of the response surface was also investigated for the response function by performing a regression analysis. Moreover, graphical optimization was carried out to determine the optimum conditions for the dried arils in terms of quality attributes. The RSM optimized values concerning blanching time and strength of osmo solution were 25 second and 75% TSS, respectively. The developed osmo-air dried product had 21% yield and sensory scores on the nine point hedonic rating scale for different sensory parameters such as appearance, odor, taste and overall acceptability were 8.16, 9, 9, and 8.6, respectively.