Optimization of Bioactive Fortification in Apple Snacks through Vacuum Impregnation Using Response Surface Methodology

Abstract

Fortification of apple slices with t-resveratrol glucoside was obtained by vacuum impregnation (VI) of apple slices with a solution containing grape juice using response surface methodology (RSM). Three independent variables of the VI process: vacuum pressure, application time and relaxation time, were coded at five levels in a central composite design. The VI-treated and dried apple slices were analyzed for t-resveratrol glucoside concentration and textural attributes (gradient and linear distance). Multiple response optimization revealed the following optimum VI condi-tions for the bioactive enrichment and improved textural quality of dried apple slices: vacuum pressure of 6 in. of Hg, application time of 10 min, and relaxation time of 22.5 min.