Magnolia bark could take the edge off bad breath much more effectively than mints alone, US researchers say.
Not just nice in the garden: the magnolia tree
The extract, already used in the treatment of various disorders, may also be effective against the bacteria which cause tooth decay.
Researchers at the Wrigley Company carried out tests on nine volunteers.
Writing in the Journal of Agricultural and Food Chemistry, they found mints laced with magnolia killed 20 times more bacteria than mints without.
After half an hour, the magnolia mint had killed more than 60% of the bacteria, compared to just 3.6% among those who had consumed a normal mint.
All the volunteers were healthy, and had just eaten lunch.
Bacteria killed included those responsible for bad breath problems such as halitosis, as well as Streptococcus mutans, blamed for tooth decay.
"Bad breath or halitosis is a major social and psychological problem that affects the majority of the general population," the researchers wrote.
"Magnolia bark extract demonstrated a significant anti-bacterial activity against organisms responsible for oral malodour and can be incorporated into mints and chewing gum for improved breath freshening benefits."
Advocates of magnolia have long praised its properties, claiming it can alleviate the symptoms of conditions ranging from rheumatism to asthma.
Dr Nigel Carter, chief executive of the British Dental Health Foundation said the results of the study looked "very promising".
"Standard mints and mouthwashes only really mask bad breath temporarily and while chewing gum can be effective due to its ability to increase the flow of saliva, this research might be another step forward in it developing an even greater role in good oral health practice."
But he stressed that brushing teeth twice a day remained as important as ever for good oral health.