Optimization of Osmo-convective Dehydration Process for the Development of Honey-ginger Candy Using Response Surface Methodology
Osmotic dehydration of ginger with honey is an interesting alternative for the development of confectionary-based functional food with extended shelf life. Response surface methodology (RSM) was used to investigate the effects of process variables on solid gain, water loss, and overall acceptability of honey-ginger candy. The process variables included blanching time (6?10 min), osmotic solution temperature (30?50°C), immersion time (90?150 min), and convective drying temperature (50?70°C). The honey to ginger ratio was 4:1 (w/w) during all the experiments. Ginger cubes were blanched before osmotic dehydration to increase the permeability of the outer cellular layer of tissue. After osmotic concentration of ginger with honey, convective dehydration was done to final moisture content of 3?5% (w.b.) to make it a shelf-stable product. Finally, osmo-convectively dried ginger was coated with sucrose for candy preparation. The optimum osmo-convective process conditions for maximum solid gain, water loss, and overall acceptability of honey-ginger candy were 7.07 min blanching time, 50°C solution temperature, 150 min immersion time, and 60°C convective drying temperature.