Powder fractions of D. glomerata were produced by drying the fruits to 10% moisture, grinding followed by sieving to differentiate powders of sizes <180 Âµm, 180-212 Âµm, 212-315 Âµm and â‰¥315 Âµm. The obtained powders were analysed for their phenolics profile and evaluate in vivo antioxidant activities in rats. Lyophilized ethanolic extract and crude powder were used for comparison. The phenolic compounds (mg/100g): epicatechin (19-30), caffeic acid (313-468), protocatechuic acid (338-799) and quercetin (369-639) were significantly correlated (r>0.65; p<0.05). For in vivo antioxidant properties, the rats fed with fine powders reduced their malondialdehyde in all organs from 19 to 64% (180-212 Âµm) and 29 to 38% (<180 Âµm), while increased in catalase (250-1310% and 249-1121%) and superoxide dismutase (72-251 and 5-404%) were observed, respectively in the 180-212 Âµm fraction and ethanolic extract powder. The 180-212 Âµm fraction with high phenolic contents protected rats from oxidation by modulating malondialdehyde, superoxide dismutase and catalase levels similar to ethanolic extract powder, although still lower than vitamin C. Thus, sieving fractionation has a huge potential as substitute to ethanol extraction of phenolic compounds from D. glomerata to obtain powder fractions usable as natural bio-functional ingredients.
Keywords: Dichrostachys glomerata fruits; Powder; sieve fractionation; Phenolic compounds; Antioxidant bioactivity.