Antioxidant capacity and amino acid profile of millet bran wine and the synergistic interaction between major polyphenols

Abstract

Millet bran, the by-product of millet processing industry, contains an abundance of phytochemicals, especially polyphenols. The main objective of this study was brewing antioxidant wine from millet bran, as well as the nutritional evaluation. The total polyphenol content of wine samples was determined by Folin-Ciocalteu colorimetric method, and the antioxidant capacity was evaluated by DPPH radical-scavenging capacity, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP). Results showed that millet bran wine (MBW) contained as much as six times of total polyphenols compared with millet wine (MW), and performed considerably stronger antioxidant activity in DPPH, TEAC and FRAP assays. More than sixfold of total amino acids (AA) were found in MBW than in MW. Moreover, the indispensable AA and functional AA were also abundant in MBW. The major polyphenol compounds in MBW were identified using HPLC, including vanillic acid, syringic acid (SA), -coumaric acid (CA) and ferulic acid (FA). They exhibited synergism in the antioxidant assays, especially the combinations of SA and CA, SA and FA. This study not only provides evidence for MBW as a nutraceutical with antioxidant activity, but also opens new avenues in the area of making comprehensive utilization of agricultural by-products.

Effect of Different Processing Methods on the Accumulation of the Phenolic Compounds and Antioxidant Profile of Broomcorn Millet (Panicum miliaceum L.) Flour

“…Accordingly, increases in the amounts of solubilized phenolic compounds that occurred during roasting increase the antioxidant activities in plant foods. The phenolic compounds especially phenolic acids of millet are oxidized above 110 °C [48]. Considering this point, in this study, the processing temperature of the millet was fixed at 110 °C.…”

Genetics and Genomics Interventions for Promoting Millets as Functional Foods

“…The higher amounts of polyphenol content in millet grains impart massive health benefits, including antioxidative properties, metabolic syndrome, and aging-related problems [ 39 ]. The bioactive compounds extracted from millet grains include gallic acid, caffeic acid, gentisic acid, p- coumaric acid, p-hydroxybenzoic acid, vanillic acid, syringic acid, sinapic acid, salicylic acid, ascorbic acid, chlorogenic acid, catechol, and kaempferol [ 40 - 42 ]. These phenolic compounds subsidize health benefits by ceasing the auto-oxidation in unsaturated fats by providing the means of reducing agents [ 43 ].…”

Nutritional Composition, Functional Properties and Food Applications of Millet Grains

“…Cereals are an excellent source of vitamin and minerals including fat soluble vitamin E, which is an essential antioxidant. The cereal grains are an easy protein source as required by Recommended Daily Allowance (RDA) but unfortunately they lack the essential amino acid lysine and therefore they must not be used as the sole source of dietary protein [38]. Cereal grains contain about 58 to 72% carbohydrates, 8 to 13% protein, 2 to 5% fat, and 2 to 11% indigestible fibre.…”