3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
Table I
Validation parameters of the analyzed sulphur substances
Analyte
Conclusions
The HS-SPME/GC/FPD method was optimized and
validated for the assay of sulphur volatile substances in malt
and beer. This method determined following volatile sulphur
substances in the beer sample: carbon disulphide, carbon
disulphide, and dimethylsulphide in the sample of malt.
Range of calibration
R2 LOQ [μg dm –3 extended relative
]
concentrations [μg dm –3 ] uncertainty [%]
carbon disulphide 0.04–0.15 0.9809 0.01 22
methionol 2.4–10.0 0.9308 0.5 25
ethylsulphide 0.15–0.70 0.9845 0.01 30
dimethylsulphide 0.10–0.50 0.9898 0.005 3
3-methylthiophen 0.05–0.20 0.9945 0.001 4
dimethyldisulphide 0.03–0.15 0.9918 0.01 13
2-methyl -1- buthanthiol 0.10–0.55 0.9768 0.05 29
diethyldisulphide 0.2–0.8 0.9782 0.05 28
dimethyltrisulphide 0.03–0.15 0.9956 0.005 25
ethylthioacetate 0.03–0.15 0.9867 0.01 15
Table II
Contents of sulphur substances in beer
[μg dm –3 ] Pale dispensed beers (n = 6) Pale lager beer (n = 6) Dark beer (n = 4) nonalcoholic beer (n = 3)
carbon disulphide 0.02–0.05 < 0.01 0.05 < 0.01
methionol 4.30–6.20 2.0–3.34 2.03–4.01 < 0.5
ethylsulphide < 0.01 < 0.01 < 0.01 < 0.01
dimethylsulphide 0.85–1.45 0.29–0.67 0.9–1.29 1.0
3-methylthiophen 0.10–0.16 < 0.001 0.18 < 0.001
dimethyldisulphide < 0.01 < 0.01 < 0.01 < 0.01
2-methyl -1-buthanthiol < 0.05 < 0.05 < 0.05 < 0.05
diethyldisulphide 0.08–0.20 0.05–0.25 0.12–0.19 0.36
dimethyltrisulphide < 0.005 < 0.005 < 0.005 < 0.005
ethylthioacetate < 0.01 < 0.01 < 0.01 < 0.01
Fig. 1. Comparison of suitability of SPME fibres for the analysis
of sulphur substances
s593
Fig. 2. DMS content in the analyzed malts
This work has been supported by project MSM
6019369701 of Czech Ministry of Education.