Pungent tasting substance in ginger reduces bad breath

How food ingredients affect our taste perception

Freising July 30, 2018

The pungent compound 6-gingerol, a constituent of ginger, stimulates an enzyme contained in saliva ­– an enzyme which breaks down foul-smelling substances.  It thus ensures fresh breath and a better aftertaste. Citric acid, on the other hand, increases the sodium ion content of saliva, making salty foods taste less salty. To find out more about food components, a team from the Technical University of Munich (TUM) and the Leibniz- Institute for Food Systems Biology investigated the effects of food components on the molecules dissolved in saliva.

Many food components contribute directly to the characteristic taste of food and beverages by means of contributing their own particular taste, scent or spiciness.  However, they also indirectly influence our sense of taste via other, still largely unknown biochemical mechanisms.  A team led by Professor Thomas Hofmann from the Chair of Food Chemistry and Molecular Sensory Science has now investigated this phenomenon in greater detail.

6-Gingerol ensures fresh breath

As the results of this study show, the pungent principle of ginger, the so-called 6-gingerol, makes the level of the enzyme sulfhydryl oxidase 1 in saliva increase 16-fold within a few seconds.  The saliva and breath analyses carried out on human volunteers show that the enzyme breaks down malodorous sulfur-containing compounds.  In this way, it is able to reduce the long-lasting aftertaste of many foods such as coffee.  "As a result, our breath also smells better," explains Prof. Hofmann, who headed the study.  The mechanism discovered could contribute to the future development of new oral hygiene products, says the head of the Leibniz- Institute for Food Systems Biology at the TUM.

Citric acid reduces our perception of saltiness

According to the study, citric acid influences our perception of taste through a completely different mechanism.  As everyone knows from personal experience, sour foods such as lemon juice stimulate salivation. The amount of minerals dissolved in saliva also increases in proportion to the amount of saliva. 

According to Prof. Hofmann, the sodium ion level in saliva rises rapidly by approximately a factor of eleven after stimulation with citric acid.  This effect makes us less sensitive to table salt.  The food chemist explains:  "Table salt is nothing other than sodium chloride, and sodium ions play a key role in the taste of salt.  If saliva already contains higher concentrations of sodium ions, samples tasted must have a significantly higher salt content in order to taste comparatively salty." 

Hofmann believes that a great deal of research still needs to be done in order to understand the complex interaction between the molecules in food that create taste, the biochemical processes that take place in saliva and our sense of taste.  Using a systems biology approach, Hofmann aims to develop a new scientific basis for the production of food with component and functional profiles that satisfy the health and sensory needs of consumers.  To this end, he and his team are combining biomolecular research methods with high-performance analytical technologies and bioinformatics methods.

Publication:

Chemosensate-Induced Modulation of the Salivary Proteome and Metabolome Alters the Sensory Perception of Salt Taste and Odor-Active Thiols. Bader M, Stolle T, Jennerwein M, Hauck J, Sahin B, Hofmann T. J Agric Food Chem. 2018 Jul 13. doi: 10.1021/acs.jafc.8b02772.

Contact:

Prof. Thomas Hofmann
Chair of Food Chemistry and Molecular Sensory Science
Leibniz Institute for Food Systems Biology at the TUM
Mail: thomas.hofmann(at)tum.de
Phone: +49 (89) 289 - 22201 or Phone 2: +49 (8161) 71-2902

The Leibniz-Institute for Food Systems Biology at 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 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 physiologically and sensorially relevant effector molecules along the entire food production chain in order to make their effects systemically understandable and predictable over the long term.

The Technical University of Munich (TUM) is one of Europe¹s leading research universities, with around 550 professors, 41,000 students, and 10,000 academic and non-academic staff. Its focus areas are the engineering sciences, natural sciences, life sciences and medicine, combined with economic and social sciences. TUM acts as an entrepreneurial university that promotes talents and creates value for society. In that it profits from having strong partners in science and industry. It is represented worldwide with the TUM Asia campus in Singapore as well as offices in Beijing, Brussels, Cairo, Mumbai, San Francisco, and São Paulo. Nobel Prize winners and inventors such as Rudolf Diesel, Carl von Linde, and Rudolf Mößbauer have done research at TUM. In 2006 and 2012 it won recognition as a German "Excellence University." In international rankings, TUM regularly places among the best universities in Germany.