The effect of sorghum type and processing on the antioxidant properties of African sorghum-based foods

Sorghum: An Underutilized Cereal Whole Grain with the Potential to Assist in the Prevention of Chronic Disease

“…(23) In general, sorghum processing decreases antioxidant activity mainly as a result of reducing levels of measurable phenolic compounds. (90)(91)(92) This may be as a result of thermal degradation or lowered extractability during the analytical procedures used for their measurement. (91) However, some processes including steeping, germination, fermentation (93) and roasting of steamed grain (94) have been reported to increase the level of polyphenolics.…”

Prediction of total phenols, condensed tannins, and 3-deoxyanthocyanidins in sorghum grain using near-infrared (NIR) spectroscopy

“…Based on previous reports (Dlamini et al, 2007, Dykes et al, 2005, total phenol concentrations greater than 15 mg GAE/g, condensed tannin concentrations above 40 mg CE/g and 3-deoxyanthocyanidin concentrations higher than 100 abs/mL/g were considered high. In the current set of samples, there were numerous entries at both the non-detectable to low levels and at the extreme high range of reported values for these traits.…”

“…Sorghum has a wide variety of sorghum phenolics and their composition is affected by the genotype (Dykes et al, 2005(Dykes et al, , 2009(Dykes et al, , 2011. For example, sorghums with a pigmented testa contain condensed tannins while black sorghums have the highest levels of 3-deoxyanthocyanidins among all sorghums (Beta et al, 1999, Dlamini et al, 2007, Dykes et al, 2005. Both condensed tannins and 3-deoxyanthocyanidins have potential health benefits such as antioxidant and anticarcinogenic properties (Devi et al, 2011, Hagerman et al, 1998, Shih et al, 2007, Turner et al, 2006, Woo et al, 2012, Yang et al, 2009.…”

“…These include colorimetric methods [i.e. Folin-Ciocalteu, Prussian blue, ferric ammonium citrate (International Organization for Standardization), vanillin/HCl, and butanol-HCl methods], which determine relative sorghum phenolic levels among genotypes (Beta et al, 1999, Chiremba et al, 2012, Dlamini et al, 2007, Dykes et al, 2005, Waniska and Rooney, 2000. High performance liquid chromatography (HPLC) coupled with photodiode array (PDA), fluorescent, and/or mass spectroscopy (MS) detectors identify and quantify specific phenolic compounds (Chiremba et al, 2012, Dykes et al, 2009, Gu et al, 2003, Svensson et al, 2010.…”

Cereal-Based Functional Foods

“…This is due to the formation of complexes of phytate with the enzymes and other nutrients that negatively affect digestive processes [57,58]. Similarly tannins and polyphenols are enzyme inhibitors of plant origin that form complexes with proteins, resulting in deactivation of digestive enzymes, reduction in protein solubility and digestibility and reduction of absorbable ions [57,60,61]. The enzymes inhibited by tannins and/or polyphenols include pepsin, trypsin, chymotrypsin, lipases, glucosidase and amylase [57,62].…”