Influence of dextrins and β-glucans on palate fullness and mouthfeel of beer

Abstract

Palate fullness (PF) and mouthfeel are important sensory attributes influencing beer quality. The molar mass of starch (dextrins) and non-starch (β-glucans) polysaccharides may influence PF (pleasant) or mouthfeel (sliminess, unpleasant), respectively. Therefore, this research aims to generate beer with wide physico-chemical responses based on various raw material characteristics to study its relation to PF and mouthfeel. To accomplish this, ten barley varieties (two harvest locations and years) were classified into three groups based on their modification characteristics. To intensify response variation, barley was malted at two modification levels (parameter steeping degree), generating 55 independent malts used to brew the same number of standardized bottom fermented beers. A trained sensory panel evaluated PF (intensity and quality) and mouthfeel (e.g., slimy) descriptors. Additionally, beers were fractionated by asymmetrical flow field-flow fractionation (AF4) in three different fractions and their molar masses were determined. The average molar mass of big size (> 10 nm) dextrins and β-glucans AF4 fraction increased analogously to barley modification characteristics. For sensory data evaluation, only beer samples brewed with malts inside the recommended brewing specifications were considered (β-glucan content in malt < 350 mg/L, ISO 65 °C). PF quality was lower on samples with β-glucan content < 100 mg/L. This group also contained fewer dextrins (attenuation > 87.4 ± 1.5%), suggesting that the balance of β-glucans and dextrins is important for PF quality. This work indicates that molar mass of starch and non-starch polysaccharides, affected by barley variety and its modification level, influences sensory perception, and hence, beer quality.Graphical