Publication no. C-2003-0214-02R |  VIEW ARTICLE

Effects of Pearling on Falling Number and alpha-Amylase Activity of Preharvest Sprouted Spring Wheat.

Gary A. Hareland (1). (1) Food technologist, USDA/ARS Hard Red Spring and Durum Wheat Quality Laboratory, North Dakota State University, Fargo, ND 58105. Phone: 701/231-7728. E-mail: <gary.hareland@ndsu.nodak.edu> Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable. Cereal Chem. 80(2):232-237. Accepted December 3, 2002. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 2003.

Preharvest sprouted wheat is often characterized by the falling number (FN) test. FN decreases in preharvest sprouted wheat as enzymatic degradation of the starchy endosperm increases. Wheat with FN values <250-275 is often discounted at the time of sale. The intent of this investigation was to evaluate the effects of debranning or pearling on the flour quality traits of five samples of wheat rated as low, med-low, medium, med-high, and sound that exhibited a range in FN values of 62-425 sec. Replicates of each sample were pearled for 30, 60, and 120 sec to remove portions of the outer bran layers before milling. FN was highly correlated with alpha-amylase activity (r > -0.97) in the med-low, medium, and med-high FN sample sets as pearling time increased. FN increased in the med-low, medium, and med-high FN samples by 128, 123, and 80%, respectively, after 120 sec of pearling. Pearling had no effect on flour FN of the low FN sample but alpha-amylase activity was significantly decreased. Pearling had little or no effect on FN and alpha-amylase activity of the sound sample. FN was moderately to strongly correlated with Rapid Visco Analyser (RVA), alveograph, and farinograph properties, and poorly correlated with protein content, flour yield, and bread loaf volume. In subsequent breadmaking studies, bread loaf volume, and crumb characteristics of flour from pearled wheat were not significantly different from loaf volume and crumb characteristics of flour from the corresponding nonpearled wheat.