Studies on coffee consumption − New biomarker proposed
N-methylpyridinium could be used as a new, practical food biomarker
In order to record coffee consumption in nutrition and health studies, researchers usually rely on self-reporting by participants. However, this is not always reliable. It would therefore be desirable to conduct additional studies to objectively verify individual consumption using biomarkers. A research team led by the Leibniz Institute for Food Systems Biology at the Technical University of Munich has now validated the suitability of a specific roasted coffee compound and proposes it as a new, practical food biomarker.
Millions of people around the world drink coffee every day. The beverage contains a large number of bioactive substances, and its health effects on the human metabolism are therefore frequently subjects of scientific studies. In many of these studies, however, the data on coffee consumption is largely based on self-reporting by the participants and is therefore not always accurate. This can affect the scientific validity of nutritional studies.
Biomarkers could provide a remedy
Reliable biomarkers could remedy this problem by using biological samples to objectively distinguish between coffee drinkers and non-coffee drinkers. "So far, however, only a few substances are known that could be used as coffee markers," says principal investigator Roman Lang from the Leibniz Institute. “However, these are not yet sufficiently validated or available in sufficient quantities to serve as reference substances for comparative measurements in nutritional studies,” he continues.
The research team, which also includes the nutritional physician Thomas Skurk and first author Beate Brandl from the ZIEL - Institute for Food & Health at the Technical University of Munich, has therefore comprehensively validated the roast coffee compound N-methylpyridinium as one such biomarker candidate for its suitability. Researchers at the Technical University of Munich first proposed the substance as a biomarker candidate in 2011 as part of a pilot study.
Data from over 460 people analyzed
As part of the scientific validation, the team analyzed existing literature data. It also analyzed urine, blood and plasma samples from more than 460 people from Freising and Nuremberg who had participated in a nutrition study conducted by the BMBF-funded enable cluster.
As the study shows, N-methylpyridinium is a compound that is specific to roasted Arabica and Robusta coffee. The substance is chemically very stable and its absorption into the organism is concentration-dependent. The substance can also be easily and reproducibly detected in various body fluids after coffee consumption, before leaving the body unchanged in the urine within a few hours to days.
Roman Lang, who heads the Biosystems Chemistry & Human Metabolism research group at the Leibniz Institute, explains: "As we have shown, N-methylpyridinium fulfills all the criteria that science demands of a biomarker to control food intake. Even if we cannot draw direct conclusions about the amount of coffee consumed due to various factors, the roasting substance is still suitable as a marker. This is because it allows us to distinguish objectively and practically between people who have drunk coffee and those who have not. We therefore propose it as a reliable qualitative biomarker for coffee consumption."
Publication: Brandl, B., Czech, C., Wudy, S.I., Beusch, A., Hauner, H., Skurk, T., and Lang, R. (2024). Validation of N-Methylpyridinium as a Feasible Biomarker for Roasted Coffee Intake. Beverages 10, 12. 10.3390/beverages10010012. www.mdpi.com/2306-5710/10/1/12
Roasted coffee beans that make the word coffee on white background
CREDIT
Gisela Olias / LSB
More Information:
About N-methylpyridinium:
N-methylpyridinium was already proposed as a biomarker candidate for coffee consumption in 2011: Lang et al., 2011 onlinelibrary.wiley.com/doi/10.1002/mnfr.201000656
N-methylpyridinium is formed from the natural alkaloid trigonelline, which is abundant in green coffee, when exposed to high heat at over 220 °C. Depending on the degree of roasting, roasted Arabica and Robusta coffee beans contain concentrations of around 0.5 to 2 mg/g of the substance - regardless of special processing methods such as steaming or decaffeinating. N-methylpyridinium is contained in brewed coffee (20-40 mg/l) and can be easily detected in blood, plasma and urine samples.
Coffee consumption in Europe and the USA:
In the USA alone, 74 percent of the population over the age of 20 describe themselves as coffee drinkers. In European countries, the calculated per capita consumption of roasted coffee in 2022 ranged from around 4 kilograms in Italy to 10 kilograms in Luxembourg.
Validation criteria:
The validation was based on criteria already proposed in 2018 for food biomarkers: plausibility, dose-response, time-response, robustness, reliability, stability, analytical performance and reproducibility. Dragsted, L.O. et al. 2018. www.ncbi.nlm.nih.gov/pmc/articles/PMC5975465/pdf/12263_2018_Article_603.pdf
Read also: New biomarkers for coffee consumption
Information on the enable cluster: www.enable-cluster.de
Information about the Institute:
The Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) comprises a new, unique research profile at the interface of Food Chemistry & Biology, Chemosensors & Technology, and Bioinformatics & Machine Learning. As this profile has grown far beyond the previous core discipline of classical food chemistry, the institute spearheads the development of a food systems biology. Its aim is to develop new approaches for the sustainable production of sufficient quantities of food whose biologically active effector molecule profiles are geared to health and nutritional needs, but also to the sensory preferences of consumers. To do so, the institute explores the complex networks of sensorically relevant effector molecules along the entire food production chain with a focus on making their effects systemically understandable and predictable in the long term.
The Leibniz-LSB@TUM is a member of the Leibniz Association, which connects 97 independent research institutions. Their orientation ranges from the natural sciences, engineering and environmental sciences through economics, spatial and social sciences to the humanities. Leibniz Institutes devote themselves to social, economic and ecological issues. They conduct knowledge-oriented and application-oriented research, also in the overlapping Leibniz research networks, are or maintain scientific infrastructures and offer research-based services. The Leibniz Association focuses on knowledge transfer, especially with the Leibniz Research Museums. It advises and informs politics, science, business and the public. Leibniz institutions maintain close cooperation with universities - among others, in the form of the Leibniz Science Campuses, industry and other partners in Germany and abroad. They are subject to a transparent and independent review process. Due to their national significance, the federal government and the federal states jointly fund the institutes of the Leibniz Association. The Leibniz Institutes employ around 21,000 people, including almost 12,000 scientists. The entire budget of all the institutes is more than two billion euros.
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JOURNAL
Beverages
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Validation of N-Methylpyridinium as a Feasible Biomarker for Roasted Coffee Intake
Espresso yourself: Wearable tech measures emotional responses to coffee
Researchers in Italy have introduced a novel approach for assessing the quality of coffee. In a pioneering new study, they have demonstrated the feasibility of using wearable technology to measure the emotional responses of coffee experts during tastings.
Published in SCI’s Journal of the Science of Food and Agriculture, the study provides an innovative solution for reducing judgement biases that can result from traditional and more subjective methods of coffee quality assessment.
Coffee is one of the most popular and widely consumed beverages in the world, with a growing number of enthusiasts worldwide. Traditionally, the assessment of coffee properties has relied on trained panellists and standardised questionnaires, leading to potential biases. However, this study marks the first instance in scientific literature where wearable sensors have been employed to examine the implicit emotional responses of experienced coffee judges.
‘This research could open a new perspective into sensory analysis of coffee tasting,’ noted Lucia Billeci, a researcher at the Institute of Clinical Physiology of the National Research Council of Italy (IFC-CNR), and corresponding author of the study. ‘Aside from the usual questionnaires, panellists and judges could be equipped by minimally invasive devices and can be monitored in terms of the emotions triggering physiological responses.’
To monitor physiological responses, the team equipped judges at an international coffee tasting competition in Milan, Italy, with sensors for measuring the electrical activity of the heart, brain and skin.
Alessandro Tonacci, a biomedical engineer at IFC-CNR, and lead author on the study, explained the significance of the biomedical signals measured.
‘We used the electrocardiographic (ECG) signal, the Galvanic Skin Response (GSR) and the electroencephalographic signal (EEG). The ECG measures the electrical activity of the cardiac muscle and is able to provide information about the autonomic nervous system branches, which are in charge for arousal and relaxation, respectively.
‘The GSR is related to the electrical activity of the human skin, correlated with emotional states, and is under direct control of the sympathetic nervous system. Finally, the EEG measures the electrical activity of the brain, measured at the scalp level, and provides information about the activation and connectivity of and between specific brain areas.’
The findings revealed significant correlations between these biomedical signals and data obtained from conventional questionnaires across all sensory domains, confirming the viability of the approach for enhancing the quality assessment of coffee.
Billeci noted that the results could have broader implications within the field of neuromarketing. ‘This approach, coupled with the ongoing advancement of artificial intelligence tools, holds the potential to guide consumers in selecting coffee blends that are more emotionally satisfying. Ultimately, it could also influence users to choose more ethical and sustainable products, while maintaining high levels of sensory satisfaction,’ she said.
The team is now looking to attract funding to carry out other investigations in specific use case scenarios related to coffee production and distribution, as well as looking beyond coffee. ‘We are now conducting other investigations on different biological matrices related to food and drinks, for example in some particular wines,’ noted Billeci.
JOURNAL
Journal of the Science of Food and Agriculture
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Taste the emotions: pilot for a novel, sensors-based approach to emotional analysis during coffee tasting