Development and optimization of novel infrared dry peeling method for ginger (Zingiber officinale Roscoe) rhizome

The novel infrared dry-peeling method was developed as an alternative to the conventional lye and abrasion peeling of ginger rhizome. The experiments on infrared dry-peeling of ginger rhizome were conducted to eliminate the use of water and chemicals in peeling process, enhance the quality of peeled rhizomes and make it a sustainable method. The effects of operating parameters like infrared temperature (300°-400 °C), product to IR heater spacing (10-30 mm) and exposure time (120-300 s) on the peeling performance were investigated. The multiple response optimization was carried out using response surface methodology. The optimum conditions were obtained at 300 °C infrared temperature, 21 mm spacing and 120 s exposure time which resulted in the peeling percentage of 92.77%, 90.40% peelability, 6.94% peeling loss and unpeeled percentage of 9.6. The comparative study of optimized infrared assisted peeling with conventional abrasion and lye peeling showed that infrared dry-peeling results in lower peeling losses. The SEM images of peels showed that IR radiation causes the desirable changes in elastic and other textural properties of the peel.