Comparison of antioxidant, β-carotene, and phenolic levels between roots and leaves across three popular sweet potato (Ipomoea batatas L.) varieties

This study aimed to compare the antioxidant activity, phenolic content, and β-carotene levels of three sweet potato varieties, namely, Beauregard, Centennial, and Georgia Jet, between their storage roots and leaves using specific methods such as ABTS assay, Folin–Ciocalteu method, and HPLC to assess the antioxidant activity, phenolic content, and β-carotene quantities, respectively. Three sweet potato varieties were cultivated and collected from the University of Arkansas at Pine Bluff research fields, and their leaf extracts were used to determine total antioxidant activity (ABTS method), total phenolic content (Folin–Ciocalteu reagent assay), and β-carotene quantity (HPLC–DAD). The total antioxidant activity was more significant in the leaves than in the roots, with the leaf activity nearly doubling the roots. The Centennial variety had the highest overall average for the roots (1373 µg/g dry weight basis) and the leaves (2666 µg/g dry weight basis) for the total antioxidant activity. On the other hand, the Georgia Jet had the lowest overall average for the roots (1053 µg/g dry weight basis), while the Beauregard had the lowest activity for the leaves (1920 µg/g dry weight basis). The Beauregard roots had the highest phenolic content average (66,231 µg/g dry weight basis), while the leaves had the second-highest average (110,721 µg/g dry weight basis). The Georgia Jet had the lowest total phenolic content average for roots and leaves. The roots had a higher β-carotene quantity than the leaves. The Georgia Jet root had the highest average (1320 µg/g dry weight basis), while the leaf average was 305 µg/g dry weight basis. The Centennial variety had the lowest β-carotene quantity for both root average (1203 µg/g dry weight basis) and leaf average (218 µg/g dry weight basis). The study found that the Beauregard variety had the highest phenolic content, while the Georgia Jet had the highest β-carotene levels. The study concluded that sweet potato leaves have higher antioxidant activity and phenolic contents, while the roots have higher β-carotene levels. Among the varieties, Beauregard had the highest phenolic contents, whereas Georgia Jet had the highest β-carotene levels. Cultivars rich in phenolic compounds, antioxidants, and β-carotene are promising for future food security.