2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

With regard to starch properties, the functionality of wheat flours, irrespective of intended end-use, have been shown to fluctuate among cultivars and within cultivars grown in diverse environments. Fluctuations could be inherently related to the various starch fractions within a flour. First, wheat starch contains two distinct granule populations (A-type and B-type), which have been shown to vary according to granule size, composition, and properties. Secondly, conventional isolation of starch from flour yields two fractions (prime and tailing), which differ in quality. Differences in flour properties observed among cultivars and/or across growing environment may be related to the ratios and/or chemical attributes of the fractions (A- vs. B-type granules; prime vs. tailing starch) present within a flour. Based on initial screening, two soft white winter wheat cultivars (Lewjain, Madsen) were selected for in-depth study across five growing locations. For each cultivar/location combination, wheat was milled to flour, which was subsequently evaluated for pasting properties. While cultivar had the most significant effect on flour pasting behavior, growing location also exerted a significant effect. Flour representing each cultivar/location combination was further segregated into native (all starch within flour), A-type, B-type, prime, and tailing starch fractions. The composition (amylose content, P content, granule size distribution) and pasting properties of each individual starch fraction were determined to relate the contributions of fractions to the properties of the original flour.