A cup of ginger tea could beat bad breath, according to a new study.
Research shows that the spice contains a chemical that destroys sulphur-containing amino acids – a major cause of halitosis.
The key is gingerol, the active ingredient that gives the spicy root its flavour.
It breaks down foul smelling substances by triggering an enzyme in saliva.
Adding a pinch to food, or brewing a pot of ginger tea, may combat the social problem that regularly embarrasses one in four people.
The breakthrough could also lead to the chemical being used in toothpastes and mouth washes.
Halitosis can lower self esteem, making people withdraw in to themselves and become less sociable. It has even been linked to damaging career prospects, as well as personal relationships.
In tests levels of sulfhydryl oxidase increased sixteen-fold in seconds when volunteers ate fresh ginger – ensuring fresh breath.
In this way, it is able to reduce the long lasting aftertaste of many foods such as coffee which contains the sulphur 2-furfurylthiol, that makes breath smell.
Food chemist Professor Thomas Hofmann, of the Technical University of Munich in Germany, said: “As a result, our breath also smells better.”
Gingerol belongs to a family of compounds that give foods their spiciness. These include capsaicin and piperine found in chilli and black pepper, respectively.
The common social problem of bad breath is caused when sulphur-containing amino acids break down in the mouth.
Prof Hofmann and colleagues say ginger reduce these dramatically – thanks to gingerol.
He said: “Intervention with gingerol induced a significant increase in the abundance of salivary sulfhydryl oxidase, which was found to cause the oxidative decline of odour-active 2-furfurylthiol, thus resulting in a decrease in the odorant levels in exhaled breath, and a reduction of the perceived sulfury after-smell.
“Therefore, sulfhydryl oxidase may be considered as a component of a molecular network triggering oral cleansing mechanisms after food ingestion.”
The findings, published in the Journal of Agricultural and Food Chemistry, could lead to the development of new toothpastes and other oral hygiene products.
Prof Hofmann said many food components contribute directly to the characteristic taste of food and beverages by means of contributing their own particular scent or spiciness.
But they also indirectly influence our sense of taste via other, still largely unknown biochemical mechanisms.
So Prof Hofmann and colleagues set out to investigate th phenomenon in greater detail by analysing the effects of the molecules when they are dissolved in saliva.
They also found citric acid found in lemons, limes and oranges, for instance, increases the sodium content of saliva, making foods taste less salty.
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 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.
He explained: “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.”
Prof 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.
Ginger has previously been shown to have a number of health benefits – including protecting against bowel cancer.
In experiments gingerol slowed the growth of human tumours in mice. Plants from the ginger family have been used for thousands of years, and have been reported to have anti-cancer properties.
It can be found in fresh, ground or capsule form – or even as ginger essential oil – and it has been linked with a host of health benefits from fighting infections to decreasing cholesterol and enhancing weight loss.