Incorporation of Fermented Brewers Spent Grain in the Production of Sourdough Bread

Abstract

The utilisation of food production by-products back into food production within a circular food economy is one of the driving examples to improve sustainability within the food industry. Brewers spent grain is the most abundant by-product from the brewing industry, with currently most of it being used as animal feed. In this study, we utilised brewers spent grain as a substrate in a solid-state fermentation in order to produce a Type-3 sourdough culture. Sourdough bread is becoming increasingly popular throughout the western world. The use of fermented brewers spent grain in the production of sourdough bread yielded sourdough bread that was acceptable by consumers. We also investigated the production and presence of the main organic acids in sourdough during the proofing process and the baking process. The baking trials showed that there was a reduction in both lactic and acetic acid content during the actual baking process. The reduction in the concentration of both organic acids appears to be at the heart of the observation that for both organic acids, there is typically a lower concentration in the crust compared to the crumb of the sourdough breads, which was observed in our sourdough breads and those commercially available.