title: Assessment of endogenous antioxidative compounds and antioxidant activities of lager beers.
abstract: BACKGROUND
  Flavour stability is increasingly becoming the limiting factor in the shelf life of beer. Increasing the antioxidant activity of beer itself could suppress the rate of oxidative reaction and improve the flavour stability of beer. This report describes the levels of phenolic compounds, melanoidins and sulfur dioxide, and antioxidant activities of 40 lager beers. The relationships between antioxidative compounds and antioxidant activity were elucidated by multivariate analysis techniques.
  
  
  RESULTS
  The results showed that the total phenolic content and the melanoidins content correlated well (P < 0.05) with antioxidant activity, while there was no significant correlation (P > 0.05) between total sulfur dioxide content and antioxidant activity. Satisfactory discrimination among beer samples with significantly different antioxidant activity was achieved by principal component analysis. Results from stepwise linear regression further demonstrated that different antioxidative components responsible for antioxidant activity were dependent on the assay used. The phenolic compound group is by far the most antioxidative compounds in beer and total phenolic content, melanoidins and sulfur dioxide together made a 22-68% contribution to the antioxidant activities of beers.
  
  
  CONCLUSIONS
  Therefore, it might be an efficient means for brewers to increase total phenolic content during brewing for improvement in flavour stability of the final beer.
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, PR China. hfzhao@scut.edu.cn
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhao
authors.forename: Huipin
authors.initials: H
authors.lastname: Li
authors.forename: Guifang
authors.initials: G
authors.lastname: Sun
authors.forename: Bao
authors.initials: B
authors.lastname: Yang
authors.forename: Mouming
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D001515:Beer / Q000032:analysis*; D006801:Humans; D016014:Linear Models; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D011108:Polymers / Q000032:analysis / Q000494:pharmacology*; D025341:Principal Component Analysis; D013458:Sulfur Dioxide / Q000032:analysis / Q000494:pharmacology*; D013649:Taste
chemical_list: D000975:Antioxidants; D010636:Phenols; D011108:Polymers; C011908:melanoidin polymers; D013458:Sulfur Dioxide