here - the 34th European Brewery Convention

More documents

Recommendations

Info

conditions that promote a compromise between the highest yield and the preservation of the carbohydrate structure are a sequential 2 min MWE at 140ºC to remove the residual starch, followed by a MWE at 180ºC and a MWE with 0.1M KOH also at 180ºC. 62% of BSG AX+AXOS were extracted, presenting 7-24 xylose residues, and a degree of phenolic acids esterification of 5-21%. The structural variability obtained allows defining specific types of compounds for different applications depending on the extraction conditions used. We thank FCT financial support of RU62/94-QOPNA and post-doc grant SFRH/BPD/70589/2010. P9 Effect of brewing process on phenolic compounds and their corresponding antioxidant activities Celine Clayeux 1 , Damien Steyer 1 , Luc Didierjean 2 , Saïd Ennahar 3 1 TWISTAROMA, Colmar, France, 2 Carlsberg Group, Strasbourg, France, 3 Université de Strasbourg, Strasbourg, France Phenolic content of extracts and their corresponding antioxidant activities at different stages of beer processing were investigated using a liquid chromatography online antioxidant detection method. Ethyl acetate extracts of barley, malt, wort and beer were separated using reverse phase HPLC and compounds eluting from the column were submitted to two UV-visible detections: one for the phenolic compounds; and the other for the reduced form of the radical cation ABTS .+ (CAS 30931-67-0). Prodelphinidin B3, procyanidin B3 and catechin were identified as three major contributors in the antioxidant activity of barley. Malting had a dramatic impact resulting in a decrease in their amounts and their associated antioxidant activities. However, their contents increased during the brewing step and then slightly decreased during hopping and fermentation. This study allowed the comparison of the phenolic contents and the corresponding antioxidant profiles of barley, malt, wort and beer. P10 Potential plant protecting substances from hops in dry-hopped beer Annika Lagemann 1 , Stefan Hanke 1 , Matthias Kippenberger 1 , Georg Stettner 1 1 Bitburger Braugruppe GmbH, Bitburg, Germany Since 2012, the traditionally established method of dry-hopping has been officially approved for beer brewing in Germany. This possibility led to a quick increase of the percentage of strongly hopped beer varieties on the german market. The aim of dry-hopping is to transfer particular aroma compounds from the hop to the finished brew. So far there seem to have been no investigations on unwanted hopspecific substances which could be additionally transfered. Therefore we investigated a possible contamination of beer with low-MRL pesticides used in hop cultivation, with particular attention being paid to myclobutanil and quinoxyfen. For our study, beers were produced with different hop additions (200 to 650 g/hl). Finally, residues of different pesticides were measured in the final product. It could be shown that myclobutanil migrate into the beer and reach values close to the legal limit. This suggests that pesticide levels in strongly hopped kinds of beer should be closely monitored. P11
Protein-thiols in beer and throughout the brewing process Signe Hoff 1 , Marianne N Lund 1 , Birthe M Jespersen 1 , Mogens L Andersen 1 1 Copenhagen University, Food Science, Frederiksberg, Denmark Protein-thiols have been suggested to be important antioxidants influencing the oxidative stability of beer. A method for quantification of total soluble protein-derived thiols in wort and beer has been developed based on HPLC separation and detection of fluorescent adducts with the maleimide compound ThioGlo 1. The amounts of protein-thiols varied between barley varieties. Increased thiol oxidation were linked to a lowering of wort filtration rates. Sweet wort was found to contain compounds able to oxidize proteinthiols. These thiol-oxidizing compounds decreased in activity through increased malt roasting; and wort boiling eliminated their activity, suggesting an enzymatic origin of the effect. Thiols have been quantified in beer in various concentrations and correlated to the oxidative stability of the beers. The levels of thiols were found to decease during storage, suggesting that thiols are intermediates in redox reactions during beer staling. P12 Analysis of flavor active carbonyls in beer by derivatization with 2,4-dinitrophenylhydrazine and HPLC-ESI-MS/MS Nina Baumjohann 1 , Diedrich Harms 1 1 VLB Berlin e.V., Central Laboratory, Berlin, Germany During beer aging plenty of flavor active carbonyls are formed by different degradation processes. Due to their very low concentrations affecting the quality of beer (e.g. 2-(E)-nonenal) a sensitive analysis method is needed. The aim of this work is to develop a robust option for the determination of flavor active carbonyls as addition or alternative to laborious GC-MS routine analysis methods. After a preliminary matrix separation, a selective derivatization of carbonyls is effected by the use of the reagent 2,4-Dinitrophenylhydrazine (2,4-DNPH). For a sensitive determination of the formed derivatives high performance liquid chromatography coupled with electrospray-ionization and tandem mass spectrometry (HPLC-ESI-MS/MS) is used. By applying the multiple reaction monitoring (MRM) the selectivity is increased. Additionally, unexpected or unknown carbonyls can be discovered by the use of different mass spectrometric experiments. P13 Evaluation of chemical physical stability of craft beers through unconventional methods Stefano Buiatti 1 , Stefano Bertoli 1 , Paolo Passaghe 1 1 University of Udine, Department of Food Science, Udine, Italy Aims: The aim of this work was to evaluate the colloidal stability of beers correlating EBC methods (sensitive proteins and Chapon test) to gluten content and antioxidant activity (AA). Methods: Three beers with different formulations were produced: the reference one 100% malted barley, the other two with increasing amounts (20 and 40%) of buckwheat. Chemical physical stability was evaluated using four indices: sensitive proteins, alcohol chill haze test, gluten content and antioxidant activity. T-test was applied for statistical analysis. Results: Both gluten analysis and antioxidant activity measurements showed a correlation with data obtained with EBC methods. Conclusions: The analysis of gluten and AA may be used as qualitative and predicitive indexes of stability being more specific than sensitive proteins and Chapon test. The use of gluten free adjuncts could lead to more stable final products with a gluten content less than 100 mg/L.
Page 1 and 2: Poster P1 Soluble dietary fiber as
Page 3: P6 Predicting the flavor stability
Page 7 and 8: 1 Lodz University of Technology, In
Page 9 and 10: avoided and the draught beer qualit
Page 11 and 12: P26 DMTS reduction through control
Page 13 and 14: Toru Kishimoto 1 , Kazuhiko Uemura
Page 15 and 16: at different stages along the brewi
Page 17 and 18: sources, to account for biological
Page 19 and 20: eer fermentation. We thank FCT for
Page 21 and 22: P51 Release of hop flavours from cy
Page 23 and 24: Unmalted adjuncts are used in brewi
Page 25 and 26: details and the relevance to manufa
Page 27 and 28: was used to evaluate the predictive
Page 29 and 30: P74 Critical view on the calculatio
Page 31 and 32: P78 The "trickle-down effect" in fl
Page 33 and 34: P83 Making gluten-free beers with b
Page 35 and 36: Innovative technologies like next g
Page 37 and 38: predictions correlated well with of
Page 39 and 40: P99 Brewery carbon footprint: A cas
Page 41 and 42: Enriqueta Martinez-Rojas 1 , Renate

here - the 34th European Brewery Convention

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?