News on fine cocoa flavor
Quickly and precisely determining the flavor profile of cocoa samples
Freising, September 17, 2021
Because a plethora of flavor compounds contribute to the distinctive taste of cocoa, its composition is difficult to analyze. Now, scientists at the Technical University of Munich (TUM) and the Leibniz Institute of Food Systems Biology (LSB) have developed a new methodology that quickly, easily, and precisely quantifies the flavor profile of cocoa samples.
The new method is already suitable for practical use in companies and can be applied at any point along the value chain from cocoa beans to chocolate. In addition, the initial research results obtained using the new method lay the foundation for a world map containing comprehensive data on flavor-relevant cocoa ingredients.
“In the future, such a map could help to further optimize processing and production processes by making the flavor profiles of cocoa-containing products, such as chocolate, objectively predictable on the basis of molecular parameters,” says food chemist Andreas Dunkel of the LSB, who played a leading role in the study.
Flavors are decisive
Various flavor substances including secondary plant compounds, such as health-promoting flavanols, are crucial for the taste of cocoa. The particular class of these substances is what creates the typical astringent feeling in the mouth which strikes us as the pleasantly bitter and slightly sour taste of cocoa or chocolate.
In cocoa producing countries, quality assessment of cocoa is currently carried out mainly by random visual inspection of the beans (cut test) and sensory trained personnel. In addition, chocolate manufacturers use time-consuming and personnel-intensive methods to test the quality of cocoa.
The new method offers significant advantages over these conventional analytical methods. “Our new methodology requires minimal sample preparation and provides quantitative data on 66 taste-decisive substances using a single mass spectrometric platform,” says Thomas Kauz, who made crucial contributions to the development of the method as part of his doctoral thesis at the Chair of Food Chemistry and Molecular Sensory Analysis at TUM. “Traditional techniques make it possible to analyze about 10 samples per week, whereas this new method allows an analysis of 200 in that time,” according to Professor Corinna Dawid, who is head of the department on behalf of Professor Thomas Hofmann. Furthermore, she states, the methodology can be easily implemented into industrial workflows.
75 cocoa samples from around the world
The team of scientists tested their new methodology on a set of 75 cocoa samples from around the world. They compared unroasted samples with those that the researchers had roasted in the lab using a uniform standard procedure. “Interestingly, we found that the roasting of the cocoa influenced the flavor profile more than the respective regional origin of the beans,” declares Andreas Dunkel.
With the help of the new methodology, it is now possible to investigate the influence of other factors including the genetic predisposition of the plants and the type of fermentation, as well. Professor Veronika Somoza, director of the LSB, and Professor Corinna Dawid both agree that a long-term goal of the joint research at TUM and LSB is to supplement the world map of cocoa with all these data on sensory active substances.
Kauz T., Dunkel A., Hofmann T. (2021) J Agric Food Chem. DOI: 10.1021/acs.jafc.1c01987. High-throughput quantitation of key cocoa tastants by means of ultra-high-performance liquid chromatography tandem mass spectrometry and application to a global sample set.
Cocoa – already popular with the Aztecs and Mayas
Cocoa was already revered as the “food of the gods” in the ancient Aztec and Maya cultures. Today, cocoa (Theobroma cacao L.) is still highly sought after as a raw material, as shown by the annual harvest volume of almost 5 million tons world wide of the brown beans alone. According to Statista, in June 2021, a ton of cocoa fetched an average retail price of just under 2,000 Euros. https://de.statista.com/statistik/daten/studie/325556/mfrage/preis-je-tonne-kakao-im-welthandel/ (in German)
Cocoa flavanols: cardioprotective effect of cocoa flavanols even in healthy individuals https://www.ernaehrungs-umschau.de/print-news/15-02-2016-kakao-flavanole-kardioprotektive-wirkung-von-kakao-flavanolen-auch -bei-gesunden/ (in German)
Origin of cocoa beans:
The cocoa samples examined in the study came from Africa, Asia, Australia and the Pacific region, as well as from North, Central, and South America.
Expert contact at LSB:
Leibniz Institute of Food Systems Biology (LSB)
Head of Research Group Integrative Food Systems Analysis (ad interim) &
Head of Subunit Databases
Phone: +49 8161 71 2903
Expert contact at TUM:
Prof. Dr. Corinna Dawid (acting head of chair)
Technical University of Munich
Chair of Food Chemistry and Molecular Sensory Science
Phone: +49 8161 71 2901
Director of LSB:
Prof. Dr. Veronika Somoza
Press contact at LSB:
Information about the LSB
The Leibniz Institute for Food Systems Biology at the Technical University of Munich 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 primary research objective 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 96 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 20,000 people, including 10,000 scientists. The entire budget of all the institutes is more than 1.9 billion euros.
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