Potential of germinated brown rice in beer brewing

Abstract

Brewing beer with cereals other than barley malt has drawn wide attention in recent years. Germinated brown rice (GBR), which contains high contents of γ-aminobutyric acid (GABA), is a well-known functional food and is widely incorporated as an ingredient in different products. However, little is known about the influence of GBR addition on the processability and quality of beer. The present study aimed to investigate the influence of different contents (0, 20, 40, and 60%) of GBR in the recipe on the beer quality. GBR beers had a lower color (7.60–15.86 EBC), alcohol content (3.02–3.67 %vol), fermentation degree (51.57–59.71%), and bitterness (11.07–14.80 IBU) than Pilsen malt (PM) beer. An enrichment was observed in GABA, which is considered a bioactive component with multiple physiological functions, in all GBR beers prepared and a maximum GABA content of 86.21 mg/L was obtained in 60% GBR beer. Volatile compounds were also analysed and the introduction of GBR led to elevated levels of higher alcohols. Beer with 20% GBR achieved the best sensory characteristics. This study evaluated the brewing potential of GBR in the brewing industry.