Brewers' spent grain from three styles of craft beer: Characterization and their rheological effects on wheat flour dough

Abstract

Background and Objectives: To use the diversity of Brewers' spent grain (BSG) from craft beer as an ingredient of functional bread, it is required to characterize and know their effects on dough and breads. The present work investigated the physicochemical characteristics of BSG, and the farinograph effects of wheat flour substituted by Baltic Porter (BP), India Pale Ale (IPA), and Weiss (W) BSGs in amounts of 10%. Results were used for predicting the end-use quality and bread-making performance of wheat flour and wheat flour-BSG blends. Reliability of prediction was verified by a baking test.Findings: BSG from barley malt beers BP and IPA were higher in protein and lower in carbohydrate content than barley/wheat malt W BSG. The heterogeneity of ground and sieved BSG was shown by pictures taken from microscopy images of endosperm, husk, and husk/endosperm particles varying in quantities, forms, and size. Water absorption of dough was slightly affected by W, while all dough containing BSG had the development time and stability lowered when compared with the control. Conclusions:The prediction of bread-making performance showed that, while control and BP reached the "bread quality" range, W and IPA scored under "bread quality" range because of their lower stability. On the baking test, specific volume of control, BP, and IPA breads were in agreement with their prediction. W bread, however, in disagreement with prediction, presented specific volume closer to the predicted as "bread quality" BP bread. Significance and Novelty: Beer style affected BSG composition and farinograph behavior of wheat flour dough-BSG blends, with the stability being the determinant parameter on defining their end-use and bread-making quality. Significant correlations of lipid content in BSG were positive for development time and negative for tolerance index. There is no standard farinograph behavior of wheat flour-BSG blends, with these effects being governed, beyond BSG composition, by protein content of wheat flour.