Evaluation of wheat products with high flavonoid content: justification of importance of marker-assisted development and production of flavonoid-rich wheat cultivars

Abstract

In the structure of the global commodity supply in the food market in modern conditions it is necessary to note the emergence of a broad group of new high-tech products, and specialized functional food with high value added. The creation of varieties with a high content of flavonoids (plant compounds that can have a positive effect on human health) is one of the important directions of plant breeding oriented on the functional foods development. Currently, however, there is a significant gap between the well-studied role of flavonoids and the genetic control of their synthesis, on the one hand, and development of the actual product of wheat with new properties, evaluation of the nutritional value of the end-use bakery products for consumption, on the other hand. In the present study we produced and investigated bakery products from wheat synthesizing bioflavonoid pigments anthocyanins in the grain pericarp. The grains of this wheat have dark purple color. Red-grained bread wheat was a control. These two wheat lines have almost similar genomes with the exception of a small part of chromosome 2A, which contains the Pp3/TaMyc1 gene regulating anthocyanin biosynthesis. The use of such an accurate model has allowed relating the observed differences precisely with anthocyanin biosynthesis. The important task was to evaluate the resistance of anthocyanins to the backing process. Therefore anthocyanin content was evaluated not only in the end-use product, but also in mixtures of flour and bran used for baking and separately in the bran. As a result, significant differences were detected in samples obtained from purple grains, compared with the control including the products that had passed a full processing cycle, including baking at elevated temperature. For the extraction of anthocyanins conditions were simulated most similar to those in the process of digestion in the stomach, in order to assess the amount of assimilable anthocyanins. By our estimates one can get up to 1.03 mg of assimilable anthocyanins with 100 g of whole-grained bread produced from anthocyanincolored grains. With 100 g of bran, the body will get up to 3.32 g of anthocyanins. In parallel with the evaluation of the anthocyanins content in all samples, the mass fraction of antioxidants was measured by using the amperometric method. The highest antioxidant capacity was shown for bran, while the least one was demonstrated for flour. Adding bran to the flour as well as the backing process increased the antioxidant capacity of wheat products. The contribution of anthocyanins to increased antioxidant capacity is not significant. It was shown that bread-making quality and organoleptic properties of bakery products made from anthocyanin-colored grains did not concede, or in some cases were higher than the corresponding properties of products obtained from control NIL grains. It was found that the presence of anthocyanin increases the shelf life of bakery products and their resistance to molding in provocative conditions. These results, combined with the known data about the beneficial health effects of anthocyanins, suggest that wheat bakery products made from anthocyanin-rich grains can be included to the list for dietary food. Marker-assisted selection accelerating the creation of new forms of crops with a high level of flavonoids can be proposed as a new direction for the expansion of domestic and export grain market potential due to the new possibilities of obtaining products of increased nutritional value and making a good profit.