PTC powder fractions of Dichrostachys glomerata Forssk. and Hibiscus sabdariffa L., sources of antioxidants with potential management of oxidative stress

Dichrostachys glomerata fruits and Hibiscus sabdariffa calyces can be processing into good functional ingredients with antioxidant properties. The plant powder fractions obtained by pulverization and controlled sieving process (< 180 µm, 180 – 212 µm, 212 – 315 µm and ≥ 315 µm) were examined for antioxidant capacity using total antioxidant power (PAOT) technology and ferric reducing antioxidant power (FRAP). Results show that both D. glomerata and H. sabdariffa powders have high antioxidant potential and large variations in the antioxidant activity in analyzed powder fractions. The highest antioxidant activity was recorded for the 180 – 212 µm and 212 – 315 µm powder fractions of D. glomerata and H. sabdariffa , respectively. Using multiple regression, it was find that the antioxidant activity of D. glomerata and H. sabdariffa powders is attributed to polyphenols. Thus, PAOT-Liquid activity was highly correlated with total polyphenols content of all plant powders (r = 0.97, p < 0.05) and the classical FRAP assay which is often used for evaluating antioxidant capacity of food matrices (r = 0.96, p < 0.05). The antioxidant potential of D. glomerata fruits and H. sabdariffa calyces powder fractions could be useful in the management of oxidative reactions.