H. KANE (1), C. O’Shaughnessy (2), A. Suoniemi-Kähärä (3); (1) Thermo Fisher Scientific, Hemel Hempstead, U.K.; (2) Campden BRI, Nutfield, U.K.; (3) Thermo Fisher Scientific, Vantaa, Finland
We describe a system capable of producing fast and reliable results from several analytes by combining automated colorimetric detection and solid-phase extraction techniques. The analyzer, Thermo Scientific Gallery Plus Beermaster, can determine bitterness and simultaneously perform other colorimetric determinations (e.g., SO2, FAN, pH, color, polyphenol, and beta-glucan) from beer or wort samples. Additionally, many water quality parameters can be measured with the same analyzer. In this study a comparison of bitterness measurement from beer and wort samples between the novel automated method and the iso-octane extraction method is presented. We also present method comparison studies from beer and wort samples for pH, color, FAN, and SO2. The bitterness method uses a solid-phase extraction column integrated into an automated photometric analyzer. In the automated bitterness method samples are first acidified and then passed through the extraction column that binds bittering substances. The sample matrix is washed out, and bittering substances are eluted and measured at 275 nm. Bitterness units are automatically calculated from absorbance results. Thermo Scientific Gallery Plus Beermaster, an automated discrete photometric analyzer, was used. Methods are fully automated using bar-coded, traceable system reagents. Bitterness calibration was performed with samples with known bitterness values. Colorimetric methods were calibrated with either water-based standard solution or samples with known values. Reference methods were EBC 9.8 for bitterness, EBC 8.10 and 9.10 for FAN, EBC 9.6 for color, EBC 9.25.1 for SO2, and EBC 9.35 and 8.17 for pH. Based on the data obtained during this study, the Thermo Scientific Gallery Plus Beermaster analyzer has been shown to give measurements of pH, bitterness, FAN, and SO2 comparable to the performance of established methods. In the case of color measurement, the Gallery Plus Beermaster had similar precision to the reference method but consistently gave slightly lower results, suggesting a factor to compensate for these differences be included in the methodology. When a factor of 1.05 was included, the Gallery Plus Beermaster was comparable to the established method. Analysis of 10 replicates of the same brand of beer showed that the Gallery Plus Beermaster had greater precision in the measurement of pH, FAN, and SO2 compared to the reference methods used in this study. Precision values for all analyses are well within the tolerances expected for spectrophotometers in the brewing industry. The Gallery Plus Beermaster is faster than more traditional methods (in the case of bitterness, FAN, and SO2 significantly faster). The low reagent and water volumes required for analysis not only reduce reagent costs but also reduce the amount of waste produced, thereby providing analysis with low environmental impact. The novel bitterness measurement uses environmentally safe reagents, with harmful iso-octane no longer required for routine analysis. The analyzer is very straightforward to use and requires minimal training and skill level to run routine analysis and maintenance.
Hilary Kane has worked in the brewing industry for more than 15 years. Having gained a degree in natural sciences at Cambridge University and an M.Phil. degree at Exeter University, Hilary decided on a career in brewing and undertook the diploma in malting, brewing, and distilling at Heriot-Watt University, in which she gained distinction. Hilary then joined Murphy & Son Ltd., working in its laboratory. Murphy & Son manufactures ingredients and processing aids for the brewing industry in the United Kingdom and abroad. In addition it provides technical analysis, advice, and troubleshooting. During her time at Murphy & Son Hilary worked in a variety of positions, including laboratory manager and quality manager. In 2012 Hilary joined Thermo Fisher Scientific as a technical sales specialist. In this position Hilary provides installation and applications support for the Thermo Fisher family of nutrient analyzers in the food and beverage sectors across the United Kingdom and Ireland, in addition to her sales role.