Extracts from the bark of the magnolia plant formulated in mints and gums can effectively tackle dental bacteria, suggests a new study from the Wm Wrigley Jr. company.
The study taps into an ever growing interest in functional chewing gum. The researchers report that extracts from the plant removed about 20 times more of the germs that cause bad breath within half an hour than placebo mints.
The study is published in the Journal of Agricultural and Food Chemistry.
Chewing gum is being seen by many as a novel and exciting delivery method for functional ingredients. Over the past two to three years gums have been formulated to contain a range of ingredients, including vitamins and probiotics.
Extracts from the bark of magnolia (Magnolia officinalis) have a long history of use in traditional Chinese medicine for stress management. The new study suggests they may also have potential as anti-microbials in functional chewing gum.
According to market researchers Leatherhead International, the global gum market is expected to increase by 17 per cent to almost $17bn (€13.5bn) in the next four years.
And Wrigley is the market leader in the sector with a more than 35 per cent share of the worldwide sector - 8 per cent greater than nearest rival Cadbury.
Wrigley scientists Michael Greenberg, Philip Urnezis, and Minmin Tian looked at the possibility of formulating extracts from magnolia bark into mints and chewing gum, and tested the efficacy of these extracts to inhibit bacteria in human saliva samples.
Using the minimum inhibition concentration (MIC) test - a quantification of the minimum concentration of extract required to inhibit growth - the researchers tested magnolia bark extract (MBE) and its two main components, magnolol and honokiol.
These experiments showed that MBE and its two main constituents strongly inhibited Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans, bacteria responsible for bad breath (halitosis). Indeed, an extract with a concentration of 0.2 per cent was reported to reduce bacterial populations by 99.9 per cent after only five minutes.
The next stage of the study involved in vivo experiments with nine healthy volunteers. Greenberg, Urnezis, and Tian took saliva samples before and after the consumption of mints and gum, with and without MBE. The results were controlled using Listerine mouthwash.
The researchers report that the MBE-enriched mints were associated with a reduction in total salivary bacteria of 62 per cent after 30 minutes and 34 per cent after an hour.
Similar results were obtained for the MBE-enriched chewing gum, where a 43 per cent reduction in total salivary bacteria was recorded after 40 minutes.
On the other hand, the mints containing no plant extract were associated with a reduction in total salivary bacteria of four per cent after 30 minutes and an increase in bacteria of 48 per cent after an hour.
Moreover, the placebo (MBE-free) gum reduced total salivary bacteria by 18 per cent after 40 minutes.
"MBE demonstrated a significant antibacterial activity against organisms responsible for oral malodour and can be incorporated in compressed mints and chewing gum for improved breath-freshening benefits," wrote the researchers.
In 2005 in Europe, Wrigley launched several new products to gain a greater foothold in the novelty flavoured gum niche.
Others are getting in on the act, too. Last year BASF Future Business, in collaboration with German biotech OrganoBalance, revealed they were targeting the dental care category with chewing gum, toothpaste or a mouthwash.
Source: Journal of Agricultural and Food Chemistry
2007, Volume 55, Pages 9465-9469, doi: 10.1021/jf072122h
"Compressed Mints and Chewing Gum Containing Magnolia Bark Extract Are Effective against Bacteria Responsible for Oral Malodor"
Authors: M. Greenberg, P. Urnezis, and M. Tian