ADVANCED BEER AROMA ANALYSIS Erich Leitner TU Graz, Institute of Analytical Chemistry and Food Chemistry, Graz, Austria
Beer Analysis - Overview Production of Beer Sample Preparation and Analysis Relevance of Aroma Fingerprinting Comprehensive GCxGC-MS Targeted Analysis of Flavor and Off Flavour Compounds-Enhancing Selectivity and Sensitivity 08.11.2017 RAFA 2017 Erich Leitner
Production of Beer and Aroma Influencing Steps Maillard reaction products ~ 30 odor active compounds contribute to the aroma Massive influence due to yeast activity Mainly formation of alcohols and esters Ageing flavours (light, temperature, oxygen ) L.C. Verhagen, Beer Flavour https://doi.org/10.1016/b978-008045382-8.00087-3 08.11.2017 RAFA 2017 Erich Leitner
Aroma Compounds in Beer So far several hundred volatiles from different chemical classes are identified in beer Compound Class Substance D. Saison et al. / Food Chemistry 114 (2009) 1206 1215 1209 H.T. Fritsch et al. / J. Agric. Food Chem. 2005, 53, 7544-7551 Sensory Threshold [µg/l] Odor Organic acids Butanoic acid 1000 Sweat, rotten milk Ester Isoamylacetate 510 Banana Higher alcohols 2-Methylbutanol 320 Fusel alcohol Vicinal diketones Diacetyl 17 fermented milk Guaiacols Guaiacol 2.5 medicinal, smoky Terpenes (R)-Linalool 0.14 Earl Grey Tea, citrus Aldehydes E-2-Nonenal 0.03 Cardboard Sulfur compounds Dimethyltrisulfide 0.03 Onion, rotten veggies
Sensory Changes during Beer Ageing B. Vanderhaegen et al. / Food Chemistry 95 (2006) 357 381
Ageing Flavours B. Vanderhaegen et al. / Food Chemistry 95 (2006) 357 381
Sample Preparation based on SPME NO solvent, NO waste NO non volatiles NO cross contamination from the solvent Fast and simple High throughput using autosampler Typical sample size 0.1-2 ml SENSITIVE ~ 1µg/L in full scan 08.11.2017 RAFA 2017 Erich Leitner
Special Shimadzu RAFA Beer Ethylacetate Amylalcohol Hexanoic acid, ethyl ester Isoamylacetate Octanoic acid, ethylester Phenylethyl Alcohol Hexyl acetate Octanoic acid Ethyl 9-decenoate 1 ml beer SPME 50/30 µm DVB/Car/PDMS 40 C 20 min 30 m RXi 5MS 0.25*1 µm -10 C (1 min)@8 C to 280 C Scan 35-350 amu, 3 scans/s 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 Bottom fermented Pils lager beer brewed by Prof. Pavel Dostalek from the University of Chemistry and Technology, Prague especially for RAFA
Automated Retention Index Calculation and Identification 8.0 7.0 6.0 (x1,000,000) TIC (1.00) 5.0 4.0 3.0 2.0 1.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 Automated RI calculation MS Database search
Aromaprofiles Abundance 3000000 2500000 2000000 1500000 1000000 500000 Time--> Abundance 0 Porter 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 3000000 2500000 2000000 1500000 1000000 500000 Time--> Abundance 0 Trappist 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 3000000 2500000 2000000 1500000 1000000 500000 Time--> 0 Craft 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 08.11.2017 RAFA 2017 Erich Leitner
Statistical Analysis Wheat Cherry flavored Porter Statistical Analysis can be helpful in the differentiation of different beer varieties Craft Trappist Ale 08.11.2017 RAFA 2017 Erich Leitner
Comprehensive GCxGC-MS 2.75 (x10,000,000) TIC (1.00) 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 Shimadzu QP2010 plus Column 1 ZB-1 HT 30*0.25*0.25 Column 2 BPX-50 2*0.15*0.15 35 C (1 min) @3 C/min to 240 C ZOEX modulator 280 C (350 ms) Modulation frequency 5 s 35-300 amu (50 scans/s) 14.5 15.0 15.5 16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0 20.5 21.0 21.5 22.0 22.5 23.0 23.5 24.0 24.5 25.0 25.5 26.0 26.5 27.0 27.5 28.0 28.5 29.0 29.5 30.0 30.5 31.0 31.5 32.0 ~500 volatiles 08.11.2017 RAFA 2017 Erich Leitner
Targeted Analysis of Flavor and Off Flavour Compounds-Enhancing Selectivity and Sensitivity
Enhancing Separation-MD GC INJ 2 Sniffing Port Heated Transfer Line INJ 1 FID MS EI,PCI,NCI GC 2 polar DEAN Switch GC 1non polar
MDGC Determination of Dimethyltrisulfide (DMTS) Preview mode (FID) GC 1: 30 m DB 5 MS 0.25*0.25 35 C(1 min)@5 C/min to 230 C 2.5 5.0 7.5 10.0 12.5 15.0 30 s transfer to column 2 47 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 min 79 111 126 50 60 70 80 90 100 110 120 130 140 Cut mode (MS) GC 2: 30 m MN Wax 0.25*0.25 70 C(1 min)@6 C/min to 220 C 126 m/z 11.25 12.00 12.75 13.25 14.00
Enhancing Selectivity Tandem MS Determination of b-damascenone (E)-b-damascenone belongs to a class of carotenoidderived carbonyl compounds. It is formed by degradation of neoxanthin, which is present in the basic ingredients of beer Sensory threshold 0.02-0.09 µg/l F. Chevance et al./j.agric.food Chem. 2002, 50, 3818-3821 Odor descriptor fruity, cooked apples, coconut, tobacco, red fruit
Scan vs MS-MS (x100,000) 1.25 1.75 (x1,000) 1.00 0.75 0.50 0.25 m/z 69 m/z 121 m/z 190 1.50 1.25 1.00 0.75 0.50 0.25 Beer 1.1 µg/l Standard 0.5 µg/l S/N 90:1 0.00 26.40 26.45 26.50 26.55 26.60 26.65 26.70 26.75 26.80 26.85 26.90 26.95 27.00 27.05 27.10 27.15 27.20 27.25 17.05 17.10 17.15 17.20 17.25 17.30 17.35 17.40 17.45 17.50 17.55 17.60 17.65 17.70 17.75 17.80 17.85 17.90 17.95 Sample size 2 ml Interferences with coeluting compound Scan 35-300 amu 5 scans/s RXi5MS 30 m*0.25*1 µm -10 C(1 min)@8 C/min to 280 C Sample size 0.1 ml No interferences Transitions 121>105 CE 10 121>77 CE 25 5 scans/s ZB5MS 30 m*0.25*0.25 µm 40 C(1 min)@10 C/min to 100 C @ 4 C/min to 160 C @25 C/min to 280 C
OH OH HO O OH O OH OH HO O OH OH Thank you for your attention and enjoy the special Shimadzu RAFA beer 08.11.2017 RAFA 2017 Erich Leitner