Study: How do different foods alter our taste perceptions?

01 Aug 2018 --- Food ingredients such as ginger and citrus can affect our taste perception, a team of researchers from the Technical University of Munich (TUM) and the Leibniz Institute for Food Systems Biology have concluded. The investigation uncovered that, in particular, a compound found in ginger can ensure fresh breath while citric acid can make foods taste less salty. Such findings could contribute to the development of oral hygiene products, the researchers note.

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.

Ginger
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 in saliva increase 16-fold within a few seconds. The saliva and breath analyses carried out on human volunteer’s 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,” says Professor 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
According to the study, citric acid influences our perception of taste through an entirely different mechanism. As people may know 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 Professor 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 says 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.