Kvasny Prum. 2015; 61(7-8): 212-220 | DOI: 10.18832/kp2015022

Rapid and Simultaneous Analysis of Qualitative Parameters of Beer by FT-NIR SpectroscopyPeer-reviewed article

Jana OLŠOVSKÁ, Pavel ČEJKA, Jiří ČULÍK, Karel ŠTĚRBA, Ladislav TENKL

¹ Výzkumný ústav pivovarský a sladařský, a.s., Lípová 15, 120 44 Praha 2 / Research Institute of Brewing and Malting, plc., Lípová 15, CZ 120 44 Praha 2

² Nicolet CZ s.r.o., Křelovická 970, 104 00 Praha 10 / Nicolet CZ s.r.o., Křelovická 970, CZ 104 00 Praha 10

Calibration models were developed for simultaneous analysis of alcohol, real extract, energy value, total saccharides and other features in beer using Fourier-transform near-infrared (FT-NIR) spectroscopy. The recorded FT-NIR spectra were correlated to the analytical data of reference methods by means of the multivariate PLS algorithm. Two groups of test beers were made from barley from two consecutive harvests. A calibration model for FT-NIR was set up using data from reference methods and was selected by means of the error of calibration (RMSEC), cross-validation (RMSECV), and the root-mean-square-error of prediction (RMSEP). It was found that calibration models for energy value, alcohol, real extract and the content of saccharides are stable and reliable. The long-term effect of calibration was evaluated by comparing external validation parameters, expressed as RMSEP_ex.

Keywords: FT-NIR, beer, alcohol, extract, energy value, saccharides, bitter compounds, proteins, polyphenols

Received: April 1, 2015; Accepted: May 4, 2015; Published: July 1, 2015