Effect of nitrogen, sulfur, and potassium chloride fertilization on the baking quality of soft red winter wheat

Abstract

Soft red winter wheat (Saluda c.v.) was fertilized using three treatments; urea, urea + KCl, and urea + sulfur. The wheat was harvested and milled and the flour produced was used to evaluate the baking quality of the wheat. Objective tests were performed on the flour samples. Significant differences in flour analysis were found among the three treatments. Farinograph curves for all treatments had medium peak time and short stability giving all samples hard red winter and hard red spring wheat characteristics. Flour from nitrogen-treated grain was most tolerant to mixing and was significantly a stronger flour according to its mixing tolerance index (MTI) value, peak time value, and absorption value. Flour treated with KCl had mixed characteristics; absorption and peak times gave it strong flour characteristics, while MTI value gave it medium-strength characteristics. Sulfur-treated flour exhibited medium-strength characteristics. Ash results demonstrated that KCl treatment had significantly higher ash content and was not suitable for the cake batter. All treatments had higher protein contents than those characteristics of cake and cookie flours. Yellow cakes were baked for all three treatments and objective and sensory tests were performed. The flour treated with nitrogen and KCl produced cakes of low quality, sunken structure, dense in texture, and low in volume. Cakes made with sulfur-treated flour retained their structure and had the highest volume, but the texture was still dense. Sensory panelists found cakes made from sulfur-treated flour lighter in texture than KCl and nitrogen treatments. Cakes from nitrogen-treated flour were perceived as being denser than the rest.