Characterization of the antioxidant activity of a wild wheat of Portuguese origin – wheat Barbela (Triticum Aestivum)

Abstract

Introduction: Interest in wheat has been increasing due to its health-related composition, which have been associated to its functional proprieties owing to bioactive compounds, such as, polyphenols [1]. Studies have shown a relation between its polyphenol content and antioxidant activity [2]. This study aimed to characterize the antioxidant activity and tocopherol content of a Portuguese origin wheat - wheat Barbela (Triticum Aestivum).

Materials and methods: Samples of a wild wheat (Triticum Aestivum) from Bragança region were analyzed. The flour sample was obtained by crushing the grain, using a working crusher (Mill Cuclotec). No refined wheat flour samples were obtained after methanol extraction carried out in a Soxlet extractor (23g/100 mL). Refined wheat flour and wheat whole grain samples were obtained after ethanol extraction. FRAP and Emmerie-Angel methods were performed to evaluate the antioxidant activity and the total tocopherol content, respectively [3,4].

Results: Regarding to antioxidant activity of no refined wheat flour a total tocopherol content (n = 3) of 47.89 ± 0.49 mg/100g was obtained. The reducing power given by the FRAP method (n = 7) was 236.17 ± 3.05 μmol Trolox/100g in no refined wheat flour, 398.73 ± 8.90 μmol trolox/100g in refined wheat flour and 41.60 ± 1.63 μmol trolox/100g in wheat whole grain.

Discussion and conclusions: The present study shows that Bragança wheat Triticum Aestivum tocopherol content (59.8 mg/kg) is higher than the same wheat species from different region [5], suggesting a nutritional benefit on its utilization in food intake. The FRAP assay results are according with Podio et al. data obtained for polyphenols free fraction [6]. According with the same authors the total phenols content is approximately of 70 mg GAE/100g [6]. Thus, the higher reducing power observed in refined flour could be attributed to an increase of free polyphenols. More search should be performed to verify the antioxidant activity of this wheat, since that could depend of an interaction between different polyphenols (free and bounded polyphenols), and its interaction with other wheat components [6].

Acknowledgements

The authors acknowledge funding from the Master in Clinical Nutrition and Egas Moniz, Cooperativa de Ensino Superior of Instituto Universitário Egas Moniz and Mr Fernando Tomas for wheat providing.