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A 12-P: OVERVIEW OF C4 PLANT CONTENT OF BEERS IN SERBIAN MARKET
Z. Kelemen, B. Marošanović, A. Bauer
Department of Instrumental Analysis, SP Laboratory, 21220 Bečej
Serbia is not a big beer producer country, but it is well known about beer drinking culture. The beer quality is measured by taste, but it is good to know for what we are paying price: for good quality barley beer or for cheapest corn beer.
Both European and Serbian law are agree, that beer should be generally comprised of four main ingredients: water, malted barley, hops, and yeast, and any addition of unlabeled adjuncts is forbidden. Within the plant kingdom, there exist plants with three different photosynthetic pathways: the C3, C4, and crassulacean acid metabolism (CAM) pathways. Many grains, including barley, are C3 plants. However, C4 plants such as corn, sorghum, and sugar cane produce the most common inexpensive sugars available on the world market. The objectives of this study were to determine if C4 carbon was present in beers widely sold in Serbia. For this purpose commercially available beers and laboratory beers were analyzed and used for data processing. Barley and corn beer were made in our laboratory following steps of real breweries, and they were mixed in different amount. From each beer sample 1µl was combusted in an elemental analyzer (Flash EA 1112 HT) which was connected to an isotope ratio mass spectrometer (ThermoFinnigan DELTA V Advantage) throw the ConFlo III interface. The resulting CO2 was analyzed for δ13C in the IRMS through continuous flow between the instruments. Calibration of used gases was done with certified reference materials.
After δ13C measurements, the results were showing that the analysed beers which are available in Serbian market contain significant percentage of C4 carbon. All the samples were with C4 carbon addition, in interval of 18-32%.
References
- J.R. Brooks, N. Buchmann, S.L. Phillips, B. Ehleringer, R.D. Evans, M. Lott, L.A. Martinelli, W.T. Pockman, D.R. Sandquist, J.P. Sparks, L. Sperry, D.G. Williams, J.R. Ehleringer, J. Agric. Food Chem,. 2002, 50,6413-6418.
