Abstract:
The effect of extraction under acidic condition (pH 2) on phenolic compounds and
antioxidant potential of aqueous extracts fromcondensed tannin sorghumbran was
investigated. The protective effect of extracts prepared with water (WE) and acidified
water (pH 2) (AWE) against free radical-induced red blood cell hemolysis and
low-density lipoprotein (LDL) oxidation was determined. The % yield (grams of
freeze-dried aqueous extract/100 g of dry sample weight), total phenolic, flavonoid
content and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity were significantly
higher in AWE than WE. AWE had 19% higher overall content of identified
phenolic acids and flavonoids thanWE.AWE showed a significantly higher degree of
protection against erythrocytemembrane oxidation than WE. Both extracts showed
protective effect against LDL oxidation. However, there were no significant differences
in tannin content and oxygen radical absorbance capacity values between the
extracts. Extracting sorghum bran under acidic conditions may release bound phenolic
compounds thereby improving the health-promoting benefits of extracts from
sorghumbran.
