Drying kinetics of food materials in infrared radiation drying: A review

In recent years, many infrared (IR) and IR-assisted drying methods such as IR-hot air, IR-vacuum, IR-microwave, and vibration aided IR-dryer have been reported for drying of food materials due to its rapid drying behavior and less processing time due to high drying rate, consumes less energy, offers better control over temperature, superior quality products, less ecological footprint and also easily it can be combined with other modes of heating technologies. The combination of IR radiation with other drying methods is very promising as it not only improves the drying rate but also preserve the food quality. IR and IR-assisted drying have been proved as a potential drying method for many food products. Drying kinetics of food materials during IR drying is very critical for the design of IR dryer, selection of appropriate drying parameters, product quality maintenance, and control and optimization of the drying process. Therefore, this paper aims to report the optimum process parameters for IR and IR-assisted drying of food materials and its drying kinetics. Similarly, critically reviewed the effect of various factors on the IR drying process such as drying rate, specific energy consumption, effective moisture diffusivity, and activation energy during drying of various food materials. Practical applications Infrared (IR) heating allows more uniform heating resulting in better quality characteristics of dried products than other drying methods. The combination of hot air and IR improves the effectiveness of drying. Drying kinetics of food materials and the factors affecting the drying characteristics of food materials during IR and IR-assisted heating are essential for the optimization of the drying process and the successful design of IR dryers with improved efficiency. Most of the IR and IR-assisted drying technologies developed for the food drying and dehydration process in the thermal food processing sector are still in a laboratory or experimental stage only. This review paper helps to analyze the further possibilities for scaling up of these technologies to industrial level or design of innovative dryer would be very beneficial to the food processing industries.