Cereal Chem. 73 (5):551-555  |  VIEW ARTICLE

Carbohydrates

Starch Damage in Soft Wheats of the Pacific Northwest.

P.-Y. Lin (1) and Z. Czuchajowska (1). (1) Graduate student, associate professor, respectively, Department of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164-6376. E-mail: <zuza@wsuvml.csc.wsu.edu> Accepted May 21, 1996. Copyright 1996 by the American Association of Cereal Chemists, Inc. 

The effect of broad growing conditions in the Pacific Northwest and varietal differences on starch damage (191 samples) of soft white winter (SWW) and club wheat flours were investigated. Starch damage was measured enzymatically by the Megazyme method and iodometrically by a Chopin Rapid Flour Tester (RFT). The overall average of starch damage (cultivars, years, and locations) showed a comparable level in SWW and club wheat flours. The starch damage in club wheat flours was more stable over crop years than in SWW wheat flours. For individual cultivars, averaged over crop years and locations, the SWW cv. Madsen had the highest 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 percentage of starch damage at 4.03%, and Moro the lowest with 3.40%. The strong correlation between starch damage values measured enzymatically by the Megazyme method and the electric current reading (E(c)) of the Chopin Rapid Flour Tester (RFT) for 191 Bühler milled soft wheat flours formed the basis for a calibration curve and respective equation. The equation was introduced into the Chopin RFT instrument and successfully used for predicting starch damage in three validation sets of samples (41 samples total) with excellent accuracy of 0.29% for soft white winter (SWW) wheat flours and 0.10% for club wheat flours. The equation could to be applicable to unknown commercial blends of soft wheat flours.