STARCH DAMAGE IN SOFT WHEATS OF THE PACIFIC-NORTHWEST

The effect of broad growing conditions in the Pacific Northwest and va rietal differences on starch damage (191 samples) of soft white winter (SWW) and club wheat flours were investigated. Starch damage was meas ured enzymatically by the Megazyme method and iodometrically by a Chop in Rapid Flour Tester (RFT). The overall average of starch damage (cul tivars, years, and locations) showed a comparable level in SWW and clu b wheat flours. The starch damage in club wheat flours was more stable over crop years than in SWW wheat flours. For individual cultivars, a veraged over crop years and locations, the SWW cv. Madsen had the high est percentage of starch damage at 4.77%, while Lewjain and Dusty had the lowest percentage of starch damage among SWW wheats, at 3.19 and 2 .76%, respectively. Among club wheats, Tres showed the highest percent age of starch damage at 4.03%, and Moro the lowest with 3.40%. The str ong correlation between starch damage values measured enzymatically by the Megazyme method and the electric current reading (E(c)) of the Ch opin Rapid Flour Tester (RFT) for 191 Buhler milled soft wheat flours formed the basis for a calibration curve and respective equation. The equation was introduced into the Chopin RFT instrument and successfull y used for predicting starch damage in three validation sets of sample s (41 samples total) with excellent accuracy of 0.29% for soft white w inter (SWW) wheat flours and 0.10% for club wheat flours. The equation could to be applicable to unknown commercial blends of soft wheat flo urs.