title: Influencing factors of hydrogen bonding intensity in beer.
abstract: The hydrogen bonding was prone to be formed by many components in beer. Different sorts of flavor substances can affect the Chemical Shift due to their different concentrations in beer. Several key factors including 4 alcohols, 2 esters, 6 ions, 9 acids, 7 polyphenols, and 2 gravity indexes (OG and RG) were determined in this research. They could be used to investigate the relationship between hydrogen bonding intensity and the flavor components in bottled larger beers through the Correlation Analysis, Principal Component Analysis and Multiple Regression Analysis. Results showed that ethanol content was the primary influencing factor, and its correlation coefficient was 0.629 for Correlation Analysis. Some factors had a positive correlation with hydrogen bonding intensity, including the content of original gravity, ethanol, isobutanol, Cl(-), K(+), pyruvic acid, lactic acid, gallic acid, vanillic acid, and Catechin in beer. A mathematic model of hydrogen bonding Chemical Shift and the content of ethanol, pyruvic acid, K(+), and gallic acid was obtained through the Principal Component Analysis and Multiple Regression Analysis , with the adjusted R(2) being 0.779 (P = 0.001). Ethanol content was proved to be the most important factor which could impact on hydrogen bonding association in beer by Principal Component Analysis. And then, a multiple non-linearity model could be obtained as follows: [Formula: see text]. The average error was 1.23 % in the validated experiment.
authors.affiliation: National Key Laboratory of Beer Biological Fermentation Engineering, Tsingtao Brewery Co. LTD, Qingdao, 266101 Shandong Province People's Republic of China ; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China ; Laboratory of Brewing Science and Engineering, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Beer Biological Fermentation Engineering, Tsingtao Brewery Co. LTD, Qingdao, 266101 Shandong Province People's Republic of China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Cargill Malt, McGinty Road West, MS 135, Wayzata, MN 55391 USA.
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Yin
authors.affiliation: Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China ; Laboratory of Brewing Science and Engineering, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China ; NO.1800, Lihu Road, Wuxi, Jiangsu People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China ; Laboratory of Brewing Science and Engineering, Jiangnan University, Wuxi, 214122 Jiangsu Province People's Republic of China.
authors.forename: Guoxian
authors.initials: G
authors.lastname: Gu
keywords: Beer; Chemical shift; Hydrogen bonding; NMR