The Aromatic Fingerprint of Fermented Coffea liberica †
1
Institute for Instrumental Analytics, Faculty of Biotechnology, Mannheim University of Applied Sciences, Paul-Wittsack-Straße 10, 68163 Mannheim, Germany
2
Department of Food Chemistry and Analysis, Technische Universität Berlin, 13355 Berlin, Germany
3
Coffee Consulate, 68163 Mannheim, Germany
*
Author to whom correspondence should be addressed.
†
Presented at the International Coffee Convention 2023, Mannheim, Germany, 30 September–3 October 2023.
Proceedings 2023, 89(1), 4; https://doi.org/10.3390/ICC2023-14838
Published: 14 August 2023
(This article belongs to the Proceedings of International Coffee Convention 2023)
Abstract
:Coffea liberica presents the smallest proportion of cultivated coffee worldwide. Its taste varies highly from C. arabica spp. or C. canephora spp. As the unfermented taste of C. liberica is often described as lactic, and animalic with aromatics of blue cheese, fermentation experiments of C. liberica coffee cherries were conducted. Coffee cherry fermentation is carried out to modify and enhance the sensory profile of green and roasted coffee beans. Various microorganisms change the composition of organic precursor compounds, reducing off-flavours during green bean coffee processing and roasting. For the comparison of the sensory properties of fermented coffee beans, SCA-trained experts grade the coffees by specific sensory attributes. Roasted and ground coffee powder, as well as ground raw coffee samples, were analysed by headspace-gas chromatography–mass spectrometry/ion mobility spectrometry (GC-MS/IMS) to determine the volatile fingerprint of unfermented and fermented C. liberica coffee. Eight different unfermented C. liberica samples were analysed and the volatile profiles compared to those of arabica spp. and canephora spp. The unfermented coffee beans differ in origin and processing. Furthermore, single-origin C. liberica fermented with two different wine yeasts was compared to unfermented C. liberica. The fermented coffee beans share the same variety, processing, and profile of roasting and differ only in their origin and fermentation inoculum. This study presents the direct comparison of the aromatic fingerprint measured in the instrument. Compound regions in the spectra associated with different coffee species and ferments are shown. The potential of GC-IMS for fast comparison of the aromatic fingerprint is demonstrated.
Author Contributions
C.K.: formal analysis, investigation, data curation, writing—original draft; S.S.: Conceptualization, resources; S.R.: writing—review and editing; P.W.: Conceptualization, supervision, funding acquisition, writing—review and editing; All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by the BMBF FH Kooperativ project “DeepAuthent”.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Data available on request due to restrictions eg privacy or ethical The data presented in this study are available on request from the corresponding author. The data are not publicly available due to preliminary results. Data will be published once the project is completed.
Conflicts of Interest
The authors declare no conflict of interest.
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MDPI and ACS Style
Kiefer, C.; Schwarz, S.; Rohn, S.; Weller, P. The Aromatic Fingerprint of Fermented Coffea liberica . Proceedings 2023, 89, 4. https://doi.org/10.3390/ICC2023-14838
AMA Style
Kiefer C, Schwarz S, Rohn S, Weller P. The Aromatic Fingerprint of Fermented Coffea liberica . Proceedings. 2023; 89(1):4. https://doi.org/10.3390/ICC2023-14838
Chicago/Turabian StyleKiefer, Catherine, Steffen Schwarz, Sascha Rohn, and Philipp Weller. 2023. "The Aromatic Fingerprint of Fermented Coffea liberica " Proceedings 89, no. 1: 4. https://doi.org/10.3390/ICC2023-14838
