Evaluation of the effect of germination on phenolic compounds and antioxidant activities in Sorghum varieties
Dicko, M.H. ; Gruppen, H. ; Traore, A.S. ; Berkel, W.J.H. van; Voragen, A.G.J. - \ 2005
Journal of Agricultural and Food Chemistry 53 (2005)7. - ISSN 0021-8561 - p. 2581 - 2588.
grain mold resistance - burkina-faso - plant - proanthocyanidins - tannins - bicolor - anthocyanidin - apigeninidin - polyphenols - thiolysis
The screening of 50 sorghum varieties showed that, on average, germination did not affect the content in total phenolic compounds but decreased the content of proanthocyanidins, 3-deoxyanthocyanidins, and flavan-4-ols. Independent of germination, there are intervarietal differences in antioxidant activities among sorghum varieties. Phenolic compounds and antioxidant activities were more positively correlated in ungerminated varieties than in germinated ones. Sorghum grains with pigmented testa layer, chestnut color glumes, and red plants had higher contents, larger diversity of phenolic compounds, and higher antioxidant activities than other sorghums. Some red sorghum varieties had higher antioxidant activities (30-80 mol of Trolox equiv/g) than several sources of natural antioxidants from plant foods. Among varieties used for "tô", "dolo", couscous, and porridge preparation, the "dolo" (local beer) varieties had the highest average content and diversity in phenolic compounds as well as the highest antioxidant activities. The biochemical markers determined are useful indicators for the selection of sorghum varieties for food and agronomic properties.
Impact of phenolic compounds and related enzymes in Sorghum varieties for resistance and susceptibility to biotic and abiotic stresses
Dicko, M.H. ; Gruppen, H. ; Barro, C. ; Traore, A.S. ; Berkel, W.J.H. van; Voragen, A.G.J. - \ 2005
Journal of Chemical Ecology 31 (2005)11. - ISSN 0098-0331 - p. 2671 - 2688.
grain mold resistance - 3-deoxyanthocyanidin phytoalexins - polyphenol oxidase - burkina-faso - peroxidase - genotypes - apigeninidin - accumulation - mechanisms - sorghicola
Contents of phenolic compounds and related enzymes before and after sorghum grain germination were compared between varieties either resistant or susceptible to biotic (sooty stripe, sorghum midge, leaf anthracnose, striga, and grain molds) and abiotic (lodging, drought resistance, and photoperiod sensitivity) stresses. Independent of grain germination, sorghum varieties resistant to biotic and abiotic stresses had on average higher contents of proanthocyanidins (PAs), 3-deoxyanthocyanidins (3-DAs), and flavan-4-ols than susceptible varieties. Results show that content of 3-DAs is a good marker for sorghum resistance to both biotic and abiotic stresses because it correlates with resistance to all stresses except for photoperiod sensitivity. The second good marker for stress resistance is content of PAs. Total phenolic compounds and the activities of related enzymes are not good markers for stress resistance in sorghum grains