The effect of organic and conventional growing systems on quality and storage protein composition of winter wheat

Abstract

Protein composition of the grain storage proteins (evaluation using electrophoresis in polyacrylamide gel - the SDS-PAGE method) and selected parameters of bread-making quality in a set of 6 winter wheat varieties from organic and conventional growing in Central Bohemia (elevation 295 m a.s.l.) were evaluated during a two-year experiment (2004 and 2005). In comparison with the varieties from organic growing, wheat varieties from the conventional growing were characterized by twice the percentage of High Molecular Weight (HMW) glutenins, responsible for dough elasticity (conventional wheat in average 25.22%, organic wheat 12.71%). At the same time, varieties from conventional growing generally reached higher, more positive values of crude protein content and wet gluten content in grain dry matter, sedimentation index by Zeleny and yield of bread. On the other hand, wheat varieties from organic growing were mainly characterized by significantly higher percentage of nutritionally valuable albumins and globulins (organic wheat in average 17.69%, conventional wheat 7.33%). In both systems of growing the highest percentage of HMW glutenins was determined in varieties from the quality group E (elite, the most suitable for bread-making), while the varieties from the quality group C (wheat unsuitable for bread-making) reached the highest percentage of residual albumins and globulins.