This work aimed to evaluate the effects of ultrasound pretreatment on the microstructure, antioxidant activity, and carotenoid retention of biofortified Beauregard sweet potato (BBSP). The pretreatment was carried out in an ultrasonic bath at 30 °C for 10 min, and it was evaluated in terms of water loss and solid gain. The drying process was performed at two different temperatures (50 and 70 °C). Six different semi-theoretical mathematical models were examined to characterize the drying curves, and quality analyses were executed. The two-terms exponential model provided the best simulation of the drying curves. Drying time was reduced by performing ultrasound pretreatment and by increasing drying temperature. The ultrasound treatment caused greater agglomeration, breakage, or strangulation of the BBSP structure, increasing porosity, and thus increasing drying rates. Drying caused a diminution of total carotenoids content and influenced antioxidant activity. However, the samples pretreated with ultrasound and dried produced lower total carotenoids loss.
Keywords: Antioxidant activity; Biofortified Beauregard; Dehydration; Microstructure; Total carotenoids; Ultrasound.
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