Ultrasound-assisted fortification of yellow sweet potato (Ipomoea batatas) with iron and ascorbic acid

Abstract

The objective of this study was to evaluate the effect of ultrasound on the incorporation of iron and ascorbic acid (AA) in sweet potato (Ipomoea batatas) and to optimize the process parameters to obtain a fortified food. The incorporation was carried out using cubes of sweet potato submerged in 0.1% m/v ferrous sulfate and 1% m/v AA solutions, treated at different times and sonication frequencies (37 and 80 kHz), at 100 watts of power and 30 ± 5°C. ANOVA and Tukey’s test at 5% significance were applied to establish significant differences and the process was evaluated using a factorial design. The results revealed that the application of ultrasound influences the content of iron and AA, incorporating greater amount of iron and AA compared to samples not treated with ultrasound. Similarly, longer times led to higher incorporation of iron and AA content in sweet potatoes; the frequency was not statistically significant. The highest iron content was 105.91 ± 0.03 mg/100 g and for AA, it was 392.65 ± 4.84 mg AAE/100 g. The defined ultrasonic process conditions produced an increase of 4928.99 and 610.65%, respectively, in iron and AA content in sweet potato.