Effect of peeling process using infrared radiation technology on physicochemical properties of kiwi fruit

Infrared (IR) radiation heating can be used as a sustainable and effective method to eliminate the use of water and chemicals in the kiwifruit peeling process and enhance the quality of final products. The objective of this study was investigated the physicochemical properties of kiwifruits after IR dry peeling. The effects of power (250-850 W), distance between IR emitter and sample (10-70 mm) and heating time (40-125 s) on the thickness of peeled kiwifruit skin, ascorbic acid content, color parameters L*, a* and b*, brix, pH and total acidity of kiwifruit were investigated. Lye peeled kiwifruits were used as a control. The operating parameters of the IR peeling system were optimized using response surface methodology by Design-Expert software. The heating with a power of 446 W at the distance of 70 mm for 125 s were found as the optimum op窶궊 conditions. In this condition the thickness of peeled kiwifruit skin, ascorbic acid content, color parameters L*, a* and b*, brix, pH and total acidity was 0.4 mm, 140 (mg / 100 g), 37.61, -4.80, 17.55, 12.03%, 3.5 and 1.16 (g / 100 g), respectively. The IR peeled kiwifruit had significantly high ascorbic acid content and low thickness of peeled kiwifruit skin, color change and brix compered to lye peeled one.