Microwave-assisted hydrothermal treatments in Chihuahua apples against Penicillium expansum

摘要

The apple is a fruit of high consume around the world. In Mexico, Chihuahua is the main state producer of apples, with 80% of the national production. The apples grown in that area (similar than Golden Delicious, but smaller in size), are know as Chihuahua apples. Heat treatments can be used to control pest and molds for perishable products, as fresh fruits, vegetables, tubers, and cut flowers. Hydrothermal microwave-assisted treatments were developed and applied in apples (Malus domestical, in orderto prevent mold decay of the fruit Four apples (around 500 g apple immersed in 2000 g of water) were treated in a microwave oven at 50% (230 W), 80% (430 W) and 100% (560 W) of the nominal power of a domestic oven (2450 MHz). In addition, a batch of apples was left untreated as a control. Apples were heated till reach the target temperature of 55°C; this value has been reported as death temperature of Penicillium expansum. After heating, the apples were cooled in water at 4°C. Based on the results oftitratable acidity, pH, °Brix, color and total phenolic determinations, the most appropriate treatment is the performed at 560 W, preserving the fruits for more than 15 days at room temperature.