COMPARATIVE EFFECTS OF WHEAT-FLOUR PROTEIN, LIPID, AND PENTOSAN COMPOSITION IN RELATION TO BAKING AND MILLING QUALITY

Variation in milling, baking, and dough-handling properties among 58 hard wheat (Triticum aestivum) flours was examined in relation to the variation in flour protein and lipid concentrations and composition and to the variation in water-soluble pentosan concentrations. Simple correlations showed no single biochemical component capable of explaining more than 41% of the variation in any given quality parameter. Similarly, no single biochemical component was highly related to all quality attributes. Canonical analyses, a multivariate statistical approach, revealed that the measured biochemical components were able to explain more than 90% of the variation in major quality attributes such as dough-handling and loaf characteristics. Flour protein concentration was found to be the primary factor contributing to variation in both dough strength and loaf characteristics. Once the primary effects of protein concentration were established, flour polar lipid concentrations showed substantial positive contributions to dough handling. Loaf textural features largely were unrelated to protein concentrations; however, glutenin concentrations, water-soluble pentosans, and flour lipids showed positive relationships. Assay of numerous biochemical components together with multivariate approaches may be needed to develop effective predictive models for observed variation in wheat end-use quality.