VIEW ARTICLE    DOI: 10.1094/ASBCJ-45-0043

Lipid-Protein Interactions in Beer and Beer Foam Brewed with Wheat Flour. Keith S. Morris, Pall Europe Ltd., Europa House, Havant Street, Portsmouth, PO1 3PD England, and James S. Hough, British School of Malting and Brewing, Birmingham University, P.O. Box 363, Birmingham B15 2TT England. J. Am. Soc. Brew. Chem. 45:0043, 1987.

Use of wheat flour as a brewing adjunct has been shown to enhance beer foam stability, as measured by the Rudin method, and also to give protection against the adverse effects of added triolein on foam stability. The efficiency of this protective action is dependent on the contact time between the lipid and the beer and is specific to triolein. The addition of palmitic acid showed different effects on the foam stability of beer brewed using wheat flour. This effect was postulated to be caused by the specific binding of triolein to proteins derived from wheat flour. Interaction between triolein and beer proteins was identified by precipitation of radiolabeled lipid with trichloroacetic acid. Use of the detergent n-octyl- β-d -glucopyranoside allowed a semiquantitative estimation of the affinity of soluble proteins for triolein. Using this method, it was found that there is no significant difference in the affinity of triolein for proteins derived from beers brewed from either an all-barley malt grist or one containing wheat flour. It was concluded that lipid-protein interactions exist in beer, but their affinity is too low to allow the identification of the proteins responsible.

Keywords: Wheat flour, Foam stability, Lipid-protein interactions, n-Octyl-β-d-glucopyranoside.