title: The impact of hop bitter acid and polyphenol profiles on the perceived bitterness of beer.
abstract: Thirty-four commercial lager beers were analysed for their hop bitter acid, phenolic acid and polyphenol contents. Based on analytical data, it was evident that the beers had been produced using a range of different raw materials and hopping practices. Principal Components Analysis was used to select a sub-set of 10 beers that contained diverse concentrations of the analysed bitter compounds. These beers were appraised sensorially to determine the impacts of varying hop acid and polyphenolic profiles on perceived bitterness character. Beers high in polyphenol and hop acid contents were perceived as having 'harsh' and 'progressive' bitterness, whilst beers that had evidently been conventionally hopped were 'sharp' and 'instant' in their bitterness. Beers containing light-stable hop products (tetrahydro-iso-α-acids) were perceived as 'diminishing', 'rounded' and 'acidic' in bitterness. The hopping strategy adopted by brewers impacts on the nature, temporal profile and intensity of bitterness perception in beer.
authors.affiliation: International Centre for Brewing Science, Bioenergy and Brewing Science Building, University of Nottingham, School of Biosciences, Division of Food Science, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Olayide
authors.initials: O
authors.lastname: Oladokun
authors.affiliation: International Centre for Brewing Science, Bioenergy and Brewing Science Building, University of Nottingham, School of Biosciences, Division of Food Science, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Amparo
authors.initials: A
authors.lastname: Tarrega
authors.affiliation: SABMiller Plc, SABMiller House, Church Street West, Woking, Surrey GU21 6HS, UK.
authors.forename: Sue
authors.initials: S
authors.lastname: James
authors.affiliation: SABMiller Plc, SABMiller House, Church Street West, Woking, Surrey GU21 6HS, UK.
authors.forename: Katherine
authors.initials: K
authors.lastname: Smart
authors.affiliation: International Centre for Brewing Science, Bioenergy and Brewing Science Building, University of Nottingham, School of Biosciences, Division of Food Science, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Hort
authors.affiliation: International Centre for Brewing Science, Bioenergy and Brewing Science Building, University of Nottingham, School of Biosciences, Division of Food Science, Sutton Bonington Campus, Loughborough LE12 5RD, UK. Electronic address: david.cook@nottingham.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Cook
mesh_terms: D001515:Beer / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D059808:Polyphenols / Q000032:analysis*; D013649:Taste
chemical_list: D010936:Plant Extracts; D059808:Polyphenols
keywords: 4-Hydroxyphenylacetic acid (PubChem CID:127); Beer; Bitterness quality; Caffeic acid (PubChem CID:689043); Catechin (PubChem CID:73160); Cinnamic acid (PubChem CID:444539); Epicatechin (PubChem CID:72276); Ferulic acid (PubChem CID:445858); Hop acids; Humulinones; Phenolic acids; Protocatechuic acid (PubChem CID:72); Sinapic acid (PubChem CID:637775); Tetrahydro-iso-humulones; Total polyphenol content; Vanillic acid (PubChem CID:8468); p-Coumaric acid (PubChem CID:637542)