The ultimate in cool could soon be coming to a grocery store near you: German researchers have developed a compound they say has 35 times the cooling power of mint, the natural coolant most widely used in food and other consumer products today. The compound also keeps its cool twice as long as mint -- with none of mint's taste or smell.
The researchers believe the development will lead to new products from ice cream to shower gel, citing consumer preferences for products with strong cooling properties and foods with intense and different flavorings. Their findings are scheduled to appear in the October 19 online issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society. The print version of the article is scheduled to appear in the November 19 issue of the journal.
"We have found the world's most powerful natural cooling agents without a mint odor," says Thomas Hofmann, Ph.D., lead researcher in the study and deputy director of the German Research Center for Food Chemistry in Garching, Germany, and an assistant professor at the Technical University of Munich.
While mint is still a popular choice for gum, candy and mouthwash (particularly when it comes to fighting bad odors), there are many instances in which consumers would like to have only its cooling or soothing effect. The new compound offers this possibility when added to food, drinks, cosmetics and other consumer products, says Hofmann.
Although no products containing the new compound are expected to appear on store shelves for another year or two, he believes it will eventually be used to impart cooling effects to chocolate, citrus beverages and even drinking water. Other possible applications include shampoo, astringents, non-mint toothpaste and deodorant, says Hofmann. It might also be used in sunblock creams or after-sun creams, he added.
In an effort to find the essence of non-mint cooling compounds as well as create more potent derivatives, the researchers evaluated 26 compounds of this class and compared their cooling effect to that of menthol, the active ingredient of mint that is derived from the oils of peppermint or spearmint plants. The potency of the compounds was evaluated subjectively using a panel of 15 people trained to detect sensory differences in taste and feel.
Of the cooling agents tested, four showed cooling activities at concentrations equal to or below menthol, but without the minty odor. The most active compound had 35 times the oral cooling activity of menthol. On the skin, the same compound showed 250 times the cooling activity of menthol, according to the researchers.
It also lasts longer. While the cooling effect of menthol lasts 15 minutes, the new compound cools for 30 minutes, they say.
Unlike menthol, the new class of cooling compounds was developed from chemicals in dark malt, the same material used to make beer and whisky. The compounds, known as cyclic alpha-keto enamines, are generally formed by reactions between sugars and amino acids when foods are heated. These reactions also occur in the making of coffee, hot cocoa and bread.
The exact mechanism by which these new cooling compounds exert their effect is unclear, according to Hofmann. He believes they work by specific chemical action of the sensory nerve endings (cold receptors) of the mouth or skin.
Funding for this research was provided by the German Research Center for Food Chemistry as well as the food industry.
The online version of the research paper cited above was initially scheduled to be published October 19 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail to firstname.lastname@example.org or calling the contact person for this release.
Thomas Hofmann, Ph.D., is deputy director of the German Research Center for Food Chemistry in Garching, Germany, and an assistant professor at the Technical University of Munich.