Quality of winter wheat in relation to heat and drought shock after anthesis
K. Balla, M. Rakszegi, Z. Li, F. Békés, S. Bencze, O. Veiszhttps://doi.org/10.17221/227/2010-CJFSCitation:Balla K., Rakszegi M., Li Z., Békés F., Bencze S., Veisz O. (2011): Quality of winter wheat in relation to heat and drought shock after anthesis. Czech J. Food Sci., 29: 117-128.
Raw material quality, which is influenced not only by the protein content, insoluble protein polymers, and glutenin-to-gliadin ratio but also by the starch granule size, is very important for the quality of bakery products. This study investigated the effect of high temperature and drought (during grain-filling) on the quality and components yield of five winter wheat varieties. Drought and drought + heat were found to have a much greater influence on the yield and quality than heat stress alone. Averaged over the varieties, the yield losses were 57% after drought, 76% after drought + heat, and only 31% after heat stresses. The reductions in the unextractable polymeric protein fraction and glutenin-to-gliadin ratio indicated a poorer grain yield quality, despite the higher protein content. Quality deterioration was observed after drought or drought + heat, while high temperatures alone resulted in no change or in a better ratio of protein components. A significant negative correlation was observed between starch granule size and relative protein content after drought, demonstrating that this parameter contributes, together with protein, to the baking quality of the flour.Keywords:
starch granule size; protein content; glutenin-to-gliadin ratio; high temperature