TY - JOUR
T1 - Comprehensive Two-Dimensional Gas Chromatography–Mass Spectrometry as a Tool for the Untargeted Study of Hop and Their Metabolites
AU - Resende, Glaucimar A.P.
AU - Amaral, Michelle S.S.
AU - Botelho, Bruno G.
AU - Marriott, Philip J.
N1 - Funding Information:
The authors would like to thank the Brazilian government agencies CNPq, FAPEMIG, and CAPES for financial support. GAPR acknowledges CNPq for the PhD scholarship (project 155078/2019-4). This study was partially funded by Coordena\u00E7\u00E3o de Aperfei\u00E7oamento de Pessoal de N\u00EDvel Superior (CAPES), Brasil\u2014Finance Code 001. Carlton & United Breweries are thanked for the provision of some hop samples.
Publisher Copyright:
© 2024 by the authors.
PY - 2024/4
Y1 - 2024/4
N2 - Since hop secondary metabolites have a direct correlation with the quality of beer and other hop-based beverages, and the volatile fraction of hop has a complex composition, requiring effective separation, here we explore the application of headspace solid-phase microextraction as a sample preparation method, coupled with comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS) analysis. The methodology involved the use of a DVB/PDMS fibre with 500 mg of hop cone powder, extracted for 40 min at 50 °C, for both GC–MS and GC×GC–MS. The varieties Azacca, Cascade, Enigma, Loral, and Zappa were studied comprehensively. The results demonstrate that GC×GC–MS increases the number of peaks by over 300% compared to classical GC–MS. Overall, 137 compounds were identified or tentatively identified and categorised into 10 classes, representing between 87.6% and 96.9% of the total peak area. The composition revealed the highest concentration of sesquiterpene hydrocarbons for Enigma, whilst Zappa showed a relatively significant concentration of monoterpene hydrocarbons. Principal component analysis for all compounds and classes, along with hierarchical cluster analysis, indicated similarities between Zappa and Cascade, and Azacca and Loral. In conclusion, this method presents an optimistic advancement in hop metabolite studies with a simple and established sample preparation procedure in combination with an effective separation technique.
AB - Since hop secondary metabolites have a direct correlation with the quality of beer and other hop-based beverages, and the volatile fraction of hop has a complex composition, requiring effective separation, here we explore the application of headspace solid-phase microextraction as a sample preparation method, coupled with comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS) analysis. The methodology involved the use of a DVB/PDMS fibre with 500 mg of hop cone powder, extracted for 40 min at 50 °C, for both GC–MS and GC×GC–MS. The varieties Azacca, Cascade, Enigma, Loral, and Zappa were studied comprehensively. The results demonstrate that GC×GC–MS increases the number of peaks by over 300% compared to classical GC–MS. Overall, 137 compounds were identified or tentatively identified and categorised into 10 classes, representing between 87.6% and 96.9% of the total peak area. The composition revealed the highest concentration of sesquiterpene hydrocarbons for Enigma, whilst Zappa showed a relatively significant concentration of monoterpene hydrocarbons. Principal component analysis for all compounds and classes, along with hierarchical cluster analysis, indicated similarities between Zappa and Cascade, and Azacca and Loral. In conclusion, this method presents an optimistic advancement in hop metabolite studies with a simple and established sample preparation procedure in combination with an effective separation technique.
KW - essential oil
KW - GC×GC–MS
KW - headspace-SPME
KW - Humulus lupulus
KW - secondary metabolites
UR - http://www.scopus.com/inward/record.url?scp=85192203516&partnerID=8YFLogxK
U2 - 10.3390/metabo14040237
DO - 10.3390/metabo14040237
M3 - Article
AN - SCOPUS:85192203516
SN - 2218-1989
VL - 14
JO - Metabolites
JF - Metabolites
IS - 4
M1 - 237
ER -