Effects of microwave heating on some oil seeds nutrient contents and colour change

Abstract

In the present study, the effects of various microwave power levels and processing times on colour change, nutrient contents of oilseeds (soybean, sunflower and canola seeds) were investigated. The samples were placed on a rotary plate of the microwave oven and heated for 2.5 or 5 minutes at two microwave output powers (540 or 900 W). After heating, the samples were examined by means of a stereo-microscope and their images were captured by means of a digital camera attached to the microscope. Lightness (L*) and yellowness (b*) of the feedstuffs used in the experiment were significantly lower, depending on the increase in power levels and durations. However, redness (a*) values were significantly higher. Also, photos of the feedstuffs' samples were taken under a stereo microscope and the images showed similar results with the colour analysis.