General Description
White crystalline powder with a fragrant caramel-butterscotch odor. pH (5% aqueous solution) 5.3.
Reactivity Profile
MALTOL(118-71-8) is weakly acidic. Reacts with bases. May react with reducing agents. Volatile with steam.
Air & Water Reactions
May be sensitive to prolonged exposure to light and air. Somewhat soluble in water at room temperature. Freely soluble in hot water [Merck]. Slightly soluble in cold water.
Fire Hazard
Flash point data on this compound are not available; however, MALTOL is probably combustible.
Chemical Properties
Maltol has a caramel–butterscotch odor and in solution it has a jam-like odor. This compound is also reported to have
a suggestive of fruity, strawberry aroma in dilute solution.
Chemical Properties
Maltol occurs in pine needles and the bark of young larch trees. It is
produced when cellulose or starch is heated and is a constituent of wood tar oils.
It forms crystals (mp 162–164°C) with a caramel-like odor, reminiscent of freshly
baked cakes.
Chemical Properties
White crystalline solid with a characteristic, caramel-like odor and
taste. In dilute solution it possesses a sweet, strawberry-like or
pineapple-like flavor and odor.
Chemical Properties
White, crystalline powder; characteristic caramel-butterscotch odor and suggestive of a
fruity-strawberry aroma in dilute solution. Melting
range 160–164C. Slightly soluble in water; more
soluble in alcohol and propylene glycol.
Occurrence
Reported found in the bark of young larch trees (Pinus larix), pine needles (Abies alba), chicory, wood tars and
oils, and roasted malt. Also reported found in wheat and rye bread, milk, butter, smoked pork, beer, cocoa, coffee, roasted barley,
filberts, peanuts, soybean, beans, tamarind, licorice, sake, malt, dried bonito, clam and cocoa liquor.
Uses
A fragrance molecule used in flavor enhancers and fragrances.
Uses
Flavoring agent, to impart "freshly baked" odor and flavor to bread and cakes.
Definition
ChEBI: A natural product found in Cordyceps sinensis.
Preparation
Maltol may be produced synthetically starting from kojic acid . Alternatively,
it can be isolated from beechwood tar or from extracts of needles from the
genus Abies. Commercially available extracts fromAbies balsamea needles,
which are also used as flavor and fragrance materials, usually contain 3–8%
maltol. It is used in aroma compositions with a caramel note and as a taste intensifier
in, for example, fruit flavors (particularly in strawberry flavor compositions).
Production Methods
Maltol is mainly isolated from naturally occurring sources such as
beechwood and other wood tars; pine needles; chicory; and the bark
of young larch trees. It may also be synthesized by the alkaline
hydrolysis of streptomycin salts or by a number of other synthetic
methods.
Aroma threshold values
Detection: 29 ppb
Taste threshold values
Taste characteristics at 100 ppm: sweet, caramellic, cotton candy, with jamy fruity and berry notes.
Toxicity evaluation
The acute oral LD50 in rats was reported to be 2.33 g/kg (1.57-3.09 g/kg) (Moreno, 1974). The acute oral 7-day LD50s in mice, rats and chicks were reported to be 848, 1440 and 3720 mg/kg, respectively (Gralla, Stebbins, Coleman & Delahunt, 1969). Acute oral LD50 values were found to be 550 mg/kg in mice, 1620 mg/kg in rabbits and 1410 mg/kg in guinea-pigs (Dow Chemical Company, 1967). The acute sc LD50 in mice was found to be 820 mg/kg. Sc injection of 400 mg/kg resulted in decreased spontaneous activity, bradycardia, hypothermia, skeletal-muscle relaxation and diminution of pinna, corneal, and ipsilateral flexor reflexes (Aoyagi, Kimura & Murata, 1974). Because of a lack of sample, 5 g/kg could only be applied to one rabbit in the dermal LD50 study, but this dosage was not lethal in the one rabbit (Moreno, 1974).
Flammability and Explosibility
Notclassified
Pharmaceutical Applications
Maltol is used in pharmaceutical formulations and food products as
a flavoring agent or flavor enhancer. In foods, it is used at
concentrations up to 30 ppm, particularly with fruit flavorings,
although it is also used to impart a freshly baked odor and flavor to
bread and cakes. When used at concentrations of 5–75 ppm, maltol
potentiates the sweetness of a food product, permitting a reduction
in sugar content of up to 15% while maintaining the same level of
sweetness. Maltol is also used at low levels in perfumery.
Pharmacology
In mice, spontaneous motor activity was depressed by sc injection oi relatively
low doses of maltol (75 mg/kg), hexobarbitone sleeping time was prolonged by sc or oral administration
of 300 mg/kg, and convulsions induced by pentylenetetrazole or strychnine were inhibited
by sc injection of toxic doses (500 mg/kg), but 1 mM concentrations of maltol had no effect on
oxygen uptake by slices of the brain cortex of the rat (Aoyagi et al. 1974).
Safety
Maltol is generally regarded as an essentially nontoxic and
nonirritant material. In animal feeding studies, it has been shown
to be well tolerated with no adverse toxic, reproductive, or
embryogenic effects observed in rats and dogs fed daily intakes of
up to 200mg/kg body-weight of maltol, for 2 years.The WHO
has set an acceptable daily intake for maltol at up to 1mg/kg body-weight.A case of allergic contact dermatitis, attributed to the
use of maltol in a lip ointment, has been reported.
LD50 (chicken, oral): 3.72 g/kg
LD50 (guinea pig, oral): 1.41 g/kg
LD50 (mouse, oral): 0.85 g/kg
LD50 (mouse, SC): 0.82 g/kg
LD50 (rabbit, oral): 1.62 g/kg
LD50 (rat, oral): 1.41 g/kg
Synthesis
By alkaline hydrolysis of streptomycin salts; also from piperdine to pyromeconic acid and subsequent methylation at the
2 position.
Metabolism
Maltol is rapidly and extensively metabolized in the dog and excreted by the conjugation pathway common to phenolic compounds. Rennhard (1971) reported that 57% of an iv dose was recovered in 24 hr, 88% of the total excretion occurring in the first 6 hr and 65-70% of the dose administered being recovered as sulphate and glucuronide conjugates
storage
Maltol solutions may be stored in glass or plastic containers. The
bulk material should be stored in a well-closed container, protected
from light, in a cool, dry place.
Purification Methods
It crystallises from CHCl3, toluene, aqueous 50% EtOH or H2O, and is volatile in steam. It can be readily sublimed in a vacuum. It forms a Cu2+ complex. [Beilstein 17 III/IV 5916, 18/1 V 114.]
Incompatibilities
Concentrated solutions in metal containers, including some grades
of stainless steel, may discolor on storage.
Regulatory Status
GRAS listed. Included in the FDA Inactive Ingredients Database
(oral solutions and syrups). Included in the Canadian List of
Acceptable Non-medicinal Ingredients.
