Finishing and Stability Session
Qi li, Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University
Co-author(s): Chunfeng Liu, Key Laboratory of Industrial
Biotechnology, Ministry of Education, Jiangnan University, China;
Jianjun Dong, R&D Center, Tsingtao Brewery Co. Ltd., Qingdao, China;
Xiangsheng Yin, Cargill Malt, Wayzata, MN, USA
ABSTRACT: The hydrogen bonding is prone to be formed by
many components in beer. Influencing factors of hydrogen bonding
intensity in beer was observed by the nuclear magnetic resonance (NMR)
method in this study. Results showed that ethanol content was the
primary influencing factor, and its correlation coefficient was 0.629
for correlation analysis (CA). Some factors had a positive correlation
with hydrogen bonding intensity, such as the content of original
gravity, ethanol, isobutanol, Cl–, K+, pyruvic
acid, and lactic acid in beer. A mathematical model of hydrogen bonding
chemical shift (CS) and the content of ethanol, pyruvic acid, and K+ was obtained through principal component analysis (PCA) and multiple regression analysis (MRA), with the adjusted R2 being 0.736 (P
= 0.001). PCA and RA methods proved that Ethanol content was the most
important factor that could impact the hydrogen bonding association in
beer. Then, a multiple non-linearity model could be obtained as follows:
hydrogen bonding association intensity (CS) = 4.916 + 0.003[E] – 0.005[P] + 5.031E–8[K2] + 1.558E–5[K×P] + 2.369E–5[E2P] – 2.207E–5[P3] + 2.244E–8[K3] – 5.947E–7[K2P] – 2.037E–5[E2K] + 4.276E–6[P2K]. The average error was 1.34% in the validated experiment.
Qi
Li received an engineering doctoral degree in fermentation engineering
from Jiangnan University in Wuxi, China. She began employment with
Jiangnan University in 1999 as a teacher in the Key Laboratory of
Industrial Biotechnology, Ministry of Education, Jiangsu Province,
China. Since 2009, she has functioned as vice president for the School
of Biotechnology in Jiangnan University. Besides serving on the Beer
Industry Association subcommittees, she has served on National
Professional Standardization Techniques Commission committees, as an
adjunct professor for Nanjing University of Technology, and as the
specially invited beer judge of China.
