Effect of processing methods on the nutraceutical and antioxidant properties of little millet (Panicum sumatrense) extracts

The effect of germination, steaming and roasting on the nutraceutical and antioxidant properties of little
millet (Panicum sumatrense) was investigated. The nutraceutical properties were determined by evaluating
the total phenolic, flavonoid and tannin contents while the antioxidant properties were studied by the
DPPH free radical scavenging activity and the iron reducing power assay. The results showed that the
total phenolic, flavonoid and tannin contents of processed little millet increased by 21.2, 25.5 and
18.9 mg/100 g, respectively, compared to native sample. The DPPH radical scavenging activity and the
iron reducing power of roasted millet extract were the highest compared to the other processed millet.
Fractionation of phenolic extracts by HPLC showed that the analytes were derivatives of benzoic acid
(gallic acid, proto-catechuic acid and vanillic acid), aromatic carboxylic acid (gentisic acid) and cinnamic
acid (syringic acid and ferulic acid). The results indicate that processing has significant effects on the
nutraceutical and antioxidant properties of little millet phenolic extracts.