The objective of this work is to investigate the effect of microwave power levels (240, 360, and 480？W) and exposure time (30, 60, 90, 120, 180, and 240？s) on various properties of cashew nuts being used for disinfestation. The nuts were analyzed for moisture content, temperature rise, colour, free fatty acid (FFA) and peroxide value (PV). Experiments were conducted according to the response surface methodology. Increase in microwave power level and exposure time caused a decrease in moisture content, increase in temperature, and change in colour. Microwave treatment to target temperatures of 50–55°C (unfavorable for insect survival) made the PV of cashew nut decrease to 1.10 to 1.66？meq O2/Kg (from an initial value of 2.08 ± 0.05) and FFA value to 0.11 to 0.51% (from an initial value of 0.68 ± 0.03). Though PV and FFA values of microwave treated cashew nut were found to increase after 6 months of storage at room conditions, the values were within the limits for acceptable quality. Microwave treated cashew nuts were free from infestation and rancidity even after 6 months of storage while the untreated nuts were found to be heavily infested at the end of 1 month of storage. 1. Introduction Cashew nuts are globally consumed for their desirable nutritional and sensory attributes [1]. Cashew nuts are good source of proteins (~20%), carbohydrates (~23%), and fats (~45%) [2]. India is the second largest producer and exporter of cashew nuts in the world accounting for 40% of world cashew production and contributing about 7% of the total export earnings. During the year 2011-2012, India exported 132,000 MT of cashew kernels valued at Rs 4400 crores (nearly 700 million dollars). USA, UAE, the Netherlands, UK, Japan, France, and Canada are the major international buyers of Indian cashews (http://www.cashewindia.org/php/cepcContents.php?CatID=29). However, cashew nuts are very susceptible to infestation by molds, insects, larvae, and so forth [3]. Insects cause considerable damage to nuts with weight and nutritional losses reducing yield and market value. It has also been reported that any abrasion in the nuts because of insect attack makes the fats liable to become rancid, and thereby integrity of kernels is lost [4]. Almost all countries have imposed a zero tolerance to insects on imported food products. Several methods have been suggested to control insect pests in agricultural commodities. Chemical fumigation is being used extensively for stored food grains. Because of increasing public concern about adverse impacts of chemical fumigation on humans and the
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