Assessment of brewing attitude of unmalted cereals and pseudocereals for gluten free beer production

In this study, 40% of unmalted gluten free (GF) grains (sorghum, millet, buckwheat, quinoa and amaranth) was used in brewing process, in gelatinized and ungelatinized form, in order to produce GF beer and to extend current knowledge about their suitability as brewing adjuncts. Partial replacement of barley malt with GF grains led to a significant decrease of extract (degrees P) and alcohol (%v/v) content compared to control beer (p < 0.05), except for quinoa beer (QB). Results from Principal Component Analysis (PCA) highlighted a satisfactory classification of experimental beers according to the two different forms of GF grains (gelatinized and ungelatinized). However, beers brewed with ungelatinized grains (mainly sorghum and quinoa) showed acceptable technological and sensory properties, thus suggesting that the pre-gelatinization step could be bypassed with a view to more environmentally and economically sustainable time-saving process. In addition, all beer samples showed a gluten content higher than 20 ppm.