Microwave Use in the Control of Ephestia kuehniella (Lepidoptera: Pyralidae) in Dried Fig and Raisin and Effects on Fruit Sensory Characteristics.

Microwave heating is an environmentally friendly method for killing pest insects and here its efficacy in the control of a pest species of dried fig and raisin was assessed. Dried fig and raisin samples were infested with Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) larvae and heated in a microwave oven at power outputs of 450, 720, and 900 W for 20, 30, 40, and 50 s. Following exposure to the microwave treatments, larval mortality and changes to organoleptic properties, which indicate consumer preference and include aroma, color, sweetness, acerbity, fragility, stiffness, and overall acceptability, were assessed. Our results showed mortality rates were greatest with the highest degree and duration of microwave exposure, where 100% mortality was recorded at 900 W with an exposure time of 50 s. The sensory evaluations of the fruit showed that microwave heating had some effect on aroma, color, fragility, sweetness, and overall acceptability, but no effect on acerbity and stiffness in dried fig, whereas in raisin, there were no impacts on acerbity, stiffness, or sweetness, but aroma, color, fragility, and overall acceptability were affected. We conclude that application of lower intensities of microwave treatment may provide acceptable levels of pest control in stored dried fruit without an associated trade-off in the reduction in quality of sensory attributes.