ABSTRACT
Infrared (IR) radiation is the part of the electromagnetic spectrum lying between ultraviolet (UV) and microwave (MW) energy. It is normally classified into three regions: near-infrared (NIR), mid-infrared (MIR), and far-infrared (FIR), corresponding to the spectral ranges of 0.78 to 1.4 µm, 1.4 to 3 µm, and 3 to 1000 µm, respectively. The application of IR heating for food processing has the following advantageous features: (1) efficient heat transfer to the food, which reduces the processing time and energy costs; (2) air in the equipment is not heated by IR. Consequently, the air temperature may be kept at normal levels; (3) the possibility of designing compact and easily automated equipment with high controllability and safety; (4) uniformity of heating more than in conventional heating because of IR penetration; and (5) danger of product overheating because of rapid heating rates, which requires exact condition control (Sakai and Hanzawa, 1994). Because of these features, IR heating has been accepted as an important means of cooking, drying, roasting, baking, blanching, and pasteurization of food and agricultural products (Lloyd et al., 2003; Ranjan et al., 2002; Staack et al., 2008a).
