From 65438 to 0970, under the leadership of Roy Randolph, Wilkinson Sword Co., Ltd. conducted extensive research on this subject. During this period, Hugh R Watson and his collaborators synthesized nearly 1200 compounds with refreshing taste activity. The most interesting thing about this kind of compound is that it can make people feel cool, so it won't irritate the eyes because of its mint smell and volatile side effects like shaving bubbles containing menthol.
WS-3
Among these molecules, two have been successfully commercialized, WS-3(N- ethyl-p-menthyl -3- carboxamide) and WS-23(2- isopropyl -N, 2,3- trimethylbutyramide).
As far as WS-3 is concerned, suppliers (such as Chihuahton and Millennium) have not specified the purity of various isomeric components of the molecule (such as menthol, which has four isomers and eight optical isomers). Watson pointed out that it is best to choose those molecules with balanced structure, such as 1r, 3r, 4s-WS-3 isomers in WS-3, which have the best cold feeling, but we don't know much about their optical isomers and their corresponding cold feeling. WS-23 (produced in Millennium) has only one structure because it has no chiral center.
In the Millennium, WS-23 was described as a nearly colorless powder with high cold taste activity, no burning, numbness and irritation. Mainly used as coolant in medicine, oral care and candy.
In the Millennium, WS-3 was described as an almost colorless white crystal, which was mainly used as a coolant in medicine, oral care and candy. Chihuaton pointed out that it would be better to mix with peppermint oil. It can produce more impact, fresh and lasting fragrance, and its taste threshold is 200ppb (measured by putting the resin impregnated paper strip in the mouth). Mosciano described the aroma as "almost tasteless, slightly alcoholic and cool" when it reached 10%. When tasted at the concentration of 10- 100ppb, "it has strong and long-term stimulation to trigeminal nerve. The coolness gradually increased steadily, and finally the mouth was full of coolness, accompanied by a slight camphor and mint flavor. "
Refrigerant on FEMA GRAS list
In addition, there are other menthone glycerol acetals from SYMRISE, and their commercial names are FRESCOLAT MGA. There are racemic and levorotatory specifications, both of which are listed in GRAS FEMA. However, the products on the market are mainly left-handed. Another product of the company is called FRESCOLAT ML, namely (-)-menthyl lactate, which has a slight mint aroma and almost tasteless taste, but it is accompanied by a lasting and pleasant cooling effect.
(-)-menthoxy-1, 2- propanediol, and the trade name of Gaosha is 10 (coolant 10), which is another commercially available coolant. Gaosha reported that its threshold was 1ppm, which was 20%- 100% of menthol. 100ppm solution can last about 20-25 minutes in the mouth, which is twice as much as menthol. It is generally believed that the strength of menthol is 20-25% of that of coolants. Some people say that the cooling intensity of the cooling agent is menthol in vaseline ointment. As far as its isomers are concerned, the strength of 2S is 2-3 times greater than that of 2R and 1.5-2 times stronger than that of racemic isomer.
Coolant 10 (2R) coolant 10 (2S)
There is also a related product, 3-( 1- methoxy) -2- methyl-1, 2- propanediol, which is also listed in FEMA GRAS list.
Cis-and trans-p-menthyl-3,8-diol
Although the literature also has the cooling effect of isopulegol, it is accompanied by mint, herbs and bitter sweetness. Takeshi Yamamoto and high sand recently found that 99.7% of (-)-isoperidol with high optical isomer purity has a fresh, pleasant and cool orange aroma. Now, the mixture of isopramine, methoxypropylene glycol and menthyl lactate is sold to the cosmetics industry as a patented product. The trade name of IsopulegolCoolact P and the chemical name of isopulegol coolact P are cis-trans p-menthyl-3,8-diol.
Recently, Gaosha applied for a patent of trans-p-menthyl-3,8-diol as a cooling agent.
A refreshing agent that does not have a cool taste itself.
Although many other compounds (2,3-dihydroxymengane, 3,3,5-trimethylcyclohexanone glycerol ketal) have been reported in the literature to have cooling effect. However, it must be mentioned that some commercial products, such as QUESTICE (methyl pyrrolidone carboxylate), have no cool taste and fragrance, and will become menthol after enzymatic hydrolysis.