Effluent free infrared radiation assisted dry-peeling of ginger rhizome: A feasibility and quality attributes

Infrared radiation (IR)-assisted peeling is one of the effulent free, environtment friendly emerging technique for tender fruit and vegetables. In this study standerdization and optimization of the infrared assisted dry-peeling method was carried out for ginger rhizome. During the investigation, the effects of selected independent parameters like infrared temperature (300-400 °C), heater to product surface spacing (10-30 mm), and treatment time (120-300 s) were studied on the peeling feasibility and quality as dependent variables. The experimental conditions were designed through CCRD statistical method. Multiple response optimization was done through RSM. The optimum conditions of selected independent variables were 300 °C IR temperature, 21 mm heater to product spacing, and 120 seconds treatment time resulted in the 90.40% of peeling efficiency, 35 °C of rhizome surface temperature, 8.67% of color change, 0.56% volatile oil loss, and 11.53 kg of firmness. The comparison of optimized infrared assisted peeling was carried out with conventional abrasion and lye peeling methods based on their quality attributes. IR assisted dry-peeling results in minimum quality losses, higher peeling efficiency and feasible over conventional peeling methods of ginger rhizome. There was zero effluent generated during infrared assisted peeling of ginger rhizome. PRACTICAL APPLICATION: Peeling is one of the foremost mandatory unit operation for processing of all fruits, vegetables, and rhizomes like ginger. Presently, lye peeling is most widely used peeling method in industries followed by mechanical peeling. Both of these methods have serious issues like huge effluent generation (BOD) and water consumption which leads to the concern about environmental issues. Infrared dry peeling is the most prominent alternative for industries having the potential to deals with environmental issues. IR peeling method can be easily designed and scaled-up as per the specific requirment of industries. Therefore, understanding its feasibility for peeling of a most difficult commodity like ginger and understanding its insight into the quality of peeled product is need of the hour.