Effect of ultrasound and steam treatments on bioaccessibility of β-carotene and physicochemical parameters in orange-fleshed sweet potato juice

Several health benefits have been associated to orange-fleshed sweet potato owing to the existence of various bioactive compounds, including β-carotene. The purpose of this study was to establish the effect of ultrasound and steam treatment on the bioaccessibility of β-carotene, total polyphenols, antioxidant activity, polyphenol oxidase, peroxidase activity, and color in the orange-fleshed sweet potato juice. Sweet potato juice was processed using ultrasound (0.66 W cm(−2) and 8 min), steam (2 min), and a combination of steam and ultrasound. The bioaccessibility of β-carotene was increased in processed sweet potato juice, with samples treated by ultrasound showing the highest bioaccessibility (76.6%). Processing had no effect on antioxidant or enzyme activity, but resulted in significant changes in the color of the juice. As a processing technology, ultrasound enables preservation or improvement of the quality of sweet potato juice, and when conbined with other treatments, facilitates the development of new products.