COMPARATIVE ANTIOXIDANT POTENTIAL OF AQUEOUS AND ACETONE / WATER EXTRACTS OF GRAINS AND BRANS OF GRANIFEROUS SORGHUM [SORGHUM BICOLOR (L.) MOENCH] HYBRID GUANIPA 71 IN VITRO

Sorghum is an important food source with substantial nutritional value. An in vitro antioxidant evaluation of different extractions of graniferous sorghum [Sorghum bicolor (L.) Moench] hybrid Guanipa 71 was proposed here. Acetone / water extracts of both grains and brans revealed strong antioxidant properties by reducing Fe³⁺ (22.9% and 42.3%) and chelating Fe²⁺ (47.3% and 32.4%), respectively. Moreover, both extracts were found to inhibit the DPPH^● radical, exhibiting an IC₅₀ (μg/mL) of 31.34 and 36.48 respectively, as well as, to reduce Molybdate (VI) through the relative antioxidant capacity assay (IC₅₀ of 330and 227.6μg/mL, respectively). They also inhibited the oxidative degradation of 2-deoxyribose (2-DR) provoked by the Fenton reaction by 29.60% and 17.77%, respectively. Furthermore, aqueous extracts of grains and brans chelated Fe⁺² by 65.09% and 59.12% and inhibited the degradation of (2-DR) in the Fenton reaction by 17.18% and 10.67%, respectively. Overall, the results showed that the acetone / water extraction from the brans of sorghum showed the best antioxidant effects, via electron transfer, radical scavenging and metal chelating activity. The antioxidant property may be attributed to the appreciable content of flavonoids and phenolic acids in the extract, including catechin, rutin, quercitrin, quercetin, luteolin and chlorogenic, caffeic, gallic and ellagic acids.