Determination of antioxidant capacities of some winter bread wheat genotypes growth under different environments in Gumushane province

In this study, it was aimed to investigate the antioxidant activities of bran and flour fractions of some bread wheat genotypes grown in organic and conventional conditions in different growth seasons under Gümüşhane conditions. For this purpose, eight bread wheat genotypes were used as material. The trials related to the material were carried out withthree replications in organic and conventional growth conditions in Gümüşhane province, Şiran district in 2013-2014 and 2014-2015 growth seasons. For determination of antioxidant activities, total flavonoid and total phenolic compound amount, Cu2+ -Cu+ reduction capacity (CUPRAC method), 1,1-Diphenyl 2-picril hydrazyl (DPPH) and 2,2- Azino-bis (3 ethylbenzo-thiazoline-6 -sulphonic acid) (ABTS) radical removal activity analyzes were performed. As standard, BHA, BHT, α-tocopherol and trolox are used. At the end of the study, DPPH radical removal activity in bread wheat flour in 2013-2014 growth season significantly changed by growth conditions. In the same season, ABTS in the flour samplesshowed significantly difference by the genotypes. Also, Cuprac reduction capacity statistically differed according to genotype (G) and YK × G interaction. In addition, all variation sources (G, YK and YK × G interaction) showed significant differences for total phenolic and total flavonoid compounds. Accordingly, inhibition values related to DPPH removal activity were found higher in organic growth conditions (24.16%) than in conventional conditions (23.09%). In 2014-2015 growth season, while the cuprac reduction capacity, total phenolic and flavonoid compounds in the flour showed significant changes in terms of all variation sources; removal activities of DPPH and ABTS did not significantly differ with respect to these variation sources. While the sources of variation differed in terms of all antioxidant properties in bran in the first growth season; in the second growth season, it was revealed that other antioxidant activities except ABTS radical removal showed significant changes in terms of all variation sources, while ABTS showed significant differences for G and YK. Thus, YK, G and YK×G interaction had statistically significant effects on the antioxidant activities of bread wheat flour and bran samples in different growth seasons. As a result, in such studies on plant basis, in determining antioxidant properties of foods; growth seasons, growth conditions and genotypes used as material should also be considered.