Concentrations of Phenolic Acids, Flavonoids and Carotenoids and the Antioxidant Activity of the Grain, Flour and Bran of Triticum polonicum as Compared with Three Cultivated Wheat Species

The experiment was performed on 66 breeding lines of Triticum polonicum, four T. durum cultivars, four T. aestivum cultivars, and one T. turanicum cultivar (Kamut (R) wheat). Wheat grain, bran, and flour were analyzed to determine the concentrations of carotenoids, free and bound phenolic acids, and flavonoids, as well as antioxidant activity in the ABTS(+) assay. The total concentrations of lutein, zeaxanthin, and beta-carotene in grain and milling fractions were determined at 3.17, 2.49, and 3.16 mg kg(-1) in T. polonicum (in grain, flour, and bran, respectively), and at 4.84, 3.56, and 4.30 mg kg(-1) in T. durum, respectively. Polish wheat grain was characterized by high concentrations of p-coumaric acid and syringic acid (9.4 and 41.0 mg kg(-1), respectively) and a low content of 4-hydroxybenzoic acid (65.2 mg kg(-1)). Kamut (R) wheat (T. turanicum) which is closely related to T. polonicum was particularly abundant in 4-hydroxybenzoic, chlorogenic, ferulic, gallic, and t-cinnamic acids. The studied Triticum species did not differ considerably in the concentrations of the eight analyzed flavonoids, and significant differences were noted only in rutin levels. The grain and milling fractions of Kamut (R) wheat were characterized by very high concentrations of quercetin, naringenin, and vitexin, but significant differences were observed only in vitexin content. Quercetin concentration in Kamut (R) wheat grain (104.8 mg kg(-1)) was more than five times higher than in bread wheat (19.6 mg kg(-1)) and more than twice higher than in Polish wheat (44.1 mg kg(-1)). Antioxidant activity was highest in bran, followed by grain and flour (4684, 1591, and 813 mu M TE g(-1), respectively). The grain and flour of the analyzed Triticum species did not differ significantly in terms of antioxidant activity.