Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
9~
This invention is concerned with foodstuffs
and other edible formulations containing sweetening agents
which are of particular value in the treatment or preven-
tion of obesity or other conditions in which the normal
function of the body in regard to carbohydrate metabolism
is impaired.
More particularly, this invention is concerned
with the preparation of foodstuffs having properties such
as appetizing~appearance, texture and taste, which are
similar to those associated with the common sugar sweeten-
ing agents. However, the foodstuffs and other edible
formulations prepared according to this invention will not
have the deleterious effects, in some people, that are
associated with those foodstuffs prepared with the common
sugar sweetening agents. Thus, this invention is con-
cerned with the sweetening of foodstuffs and other edible
formulations with no~ol sweetening agents comprising the
L-hexose monosaccharides. These sweetening agents are
unique in that their physical properties are similar to
those of the natural sugars used as sweetening agents, but
as opposed to the common sugars, these compounds are either
not metabolized by the body or are metabolized to such a
small extent, that they do not impart to the body the
detrimental effects that some people have due to the im-
proper metabolization of the common sugar sweetening
agents.
It is well known that the intake of certain
carbohydrates, and in particular D-glucose, and certain
oligosaccharides, particularly those converted to D-
glucose, such as sucrose, must be carefully regulated
-- 2 --
or entirely restricted in people suffering from conditions
such as diabetes mellitus and similar conditions wherein
the function of the pancreas is impaired in regard to
carhohydrate metabolism. A similar situation also exists
in persons in the treatment or prevention of obesity.
Numerous proposals have been made in the prior
art to provide a suitable means for the sweetening of foods
for persons who must restrict their intake of metaboliz-
able carbohydrates. However, these prior art methods
are definitely deficient in several respects and hence,
cannot be considered as ideal non-nutritive sweetening
agents. For example, the commonly used artificial
sweetening agents, such as saccharin, cyclamates and mix-
tures leave a bitter and objectional aftertaste, after
foods sweetened with these have been eaten. Likewise,
since they are used in a very minute amount, due to their
high degree of sweetness, various bulking agents must be
added to serve as a carrier and, in some cases, replace
the bulk normally supplied by the replaced sugar. The
use of bulking agents is particularly necessary in situa-
tions wherein solid foods, such as breads, cakes, cookies,
cake-icing, solid and semi-solid candies and chewing gum
are to be prepared, since it is practically impossible to
prepare this type of food with a wholesome and appetizing
appearance without the use of some bulking agent to re-
place the volume of normal sugar, which is not required
by the use of artificial sweetness. However, the use of
various bulking agents presents difficulties in that those
most effective in replacing the bulk of the normal sugar
are for the most part based upon carbohydrates, which are
metabolized by the body and, hence, have some nutritive
value.
According to one aspect of this invention there
is provided a process for the preparation of a sweetened
edible formulation in which the sweetening agent is non-
calorific and less susceptible to spoilage due to the
growth of microorganisms which comprises the step of mix-
ing a foodstuff with an amount sufficient to sweeten said
footstuff of an L-hexose monosaccharide selected from the
group consisting of L-glucose, L-allose, L-fructose, L-
gulose, L-galactose, L-altrose, L-idose, L-talose, L-
tagatose and L-psicose as a sweetening agent.
According to another aspect of the present
invention, the use of certain L-hexose monosaccharides
as sweetening agents alleviates the problems of the prior
art sweetening agents.
These novel sweetining agents have no ~itter
and objectional aEtertaste, and, further, since they have
practically the same physical properties and appearance
as the normal sugars used as sweetening agents, the pro-
blem of the use of carriers, and bulkiny agents to improve
the appearance of foodstuffs prepared therefrom is negated.
The ability of the subject L-hexoses to
function as sweetening agents is unique, in view of reports
in the prior art as to their property of being non-sweet
and having a salty taste.
Due to the fact that these L-hexose mono-
saccharides are either not metabolized by the body or they
are metabolized to such a small extent, they will have
little or no effect upon the normal body functions. Conse-
quently, these new sweetening agents may ideally be used
in foodstuffs and other edible formulations designed for
persons whose metabolizable carbohydrate intake must be
restricted because of conditions such as diabetes mellutus
or obesity.
Another outstanding feature of the use of the
subject L-hexose sweetening agents, is that formulations
prepared using them as sweetening agents are less
- 4a-
susceptible to spoilage due to the growth of various
microor~anisms than those prepared with the conventional
saccharide sweetening agents. For example, one large
problem encountered with the use of formulations such
as syrups, prepared from conventional saccharide sweetener
such as in the soft drink industry, is the decomposition
due to bacterial growth. Since the L-hexose saccharide
sweetening agents of the present invention provide little
or no nutrient value for the various microorganisms,
their growth and, hence, the corresponding spoilage of
these formulations is drastically reduced.
Other advantages of the subject L-hexose sweeten-
ing agents are that they are non-calorific and are believed
to be non-carcinogenic. Thus, they are suitable substi-
tues for sugar for persons on a reducing diet, and they
probably do not possess the carcinogenic disadvantages
associated with saccharin and cyclomates.
The term L-hexose monosaccharides as used herein
is used within the meaning of the standard terminology of
carbohydrate chemists. Thus, for example, one particu-
larly effective sweetening agent according to this inven-
tion is L-glucose, which is a stereoisomer of the widely
known sweetening agent D-glucose. The D- and L-prefixes
are used to denote the configuration of the hexose struc-
ture according to the universally accepted Fisher system
of nomenclature as modified by Rosanoff. This may be
further exemplified by reference to the following struc-
tural formulas:
~-s~c~g
- CHO CHO
H-C-OH HO-C-OH
HO-C-H H-C-OH
H-C-OH HO-C-H
H-C-OH HO-C-H
CH2H CH2H
D-Glucose L-Glucose
As ,may be ascertained from these formulas,
these two compounds are mirror images of one another.
The prefixes of D- and L- are not to be confused with
d- and 1-, which are used to denote the direction of
- optical rotation, i.e., di(dextro-) or l(levo-).
This is~discussed more fully below.
As is common in the art, the term hexose is in-
clusive of those six carbon sugars or monosaccharides,
wherein the carbonyl group is either in the aldehyde form
(aldoses) or the keto form (ketoses) and monosaccharide
refers to the simple or uncombined sugar. Typical ex-
amples of these aldoses or aldohexoses are L-talose, L-
galactose and L-allose, while typical examples of these
ketoses or ketohexoses are L-tagatose and L-psicose.
A better understanding of the products and pro-
cesses of this invention may be obtained from the examples
given below, which disclose the best mode presently con-
templated by the inventor of carrying out this invention.
.
Example 1
L-Glucose
A solution of 50 grams of ~-L-arbinose and 180
ml. of nitromethane in 100 ml. of absolute methanol was
~leated in a 3-neck, l-liter flask with a solution of lO.S
grams of 350 ml. of absolute methanol. The reaction mix-
ture was protected from moisture, refluxed and stirred for
18-20 hours. The resulting precipitate of sodium aci-
nitroalcohols was collected by~filtration and washed with
cold methanol and then with petroleum ether. The moist
salts were then dissolved in 400 ml. of cold (0C.) water
and the solution immediately deionized by passage through
a column containing 400 ml. of Dowex-50tH+) resin. The
effluent and washings were concentrated at reduced pressure
with several portions of absolute ethanol to remove resi-
dual water. The resulting crystals were filtered with the
aid of cold ethanol and the filtrate reworked to provide
two additional crops of crystals. This yielded approxi-
mately 55 grams of crude mixed nitroalcohols. This crude
product was separated by fractional crystallization from
ethanol. The less soluble fractiorl was l-deoxy-l-
nitro-L-mannitol, m.p. 133-134C. (18 gr.) and the more
soluble fra~tion l-deoxy-l-nitro-L-glucitol, m.p. 104-106C.
(15 gr.).
A solution of 5 grams of l-deoxy-l-nitro-L-
glucitol dissolved in 15 ml. of 2N sodium hydroxide W2S
added dropwise to a stirred solution of 7.5 ml. of sul-
furic acid in 9 ml. of water at room tempreature. After
dilution with 200 ml. of water, the solution was neutra-
lized to Congo red indicator with warm barium hydroxide
solution and the remaining sulfate ion precipitated with
barium acetate solution. The barium sulfate was removed
by filtration and the filtrate deionized by passage throuyh
50 ml. of Dowex-50(H+) resin. The effluent and washings
Gf ~
-- 7 --
~ 5$ ~ ~
were concentrated at reduced pressure to a syrup. This
syrup was diluted with a few drops of ethanol and allowed
to crystallize. The resulting ~-L-glucose was filtered
with the aid of ethanol; yield 2.5 grams, m.p. 146-147C.
Example 2
~-L-Allose
A solution of 13 grams of L-allono-1,4-lactone
[Austin and Humdles, ~ACS 56 1152 (1934), Hudson et al,
ibid 56 1248 (1934)] in 100 ml. of water was cooled at 0C.
in an ice-salt mixture. This was reduced by adding to the
lactone solution small amounts of a 2.5~ sodium amalgam.
During the reduction, the reaction mixture was main-
tained on the acid side of Congo red (pH 5) by the inter-
mittent addition of 20~ sulfuric acid, as needed. The
reaction mixture was agitated vigorously during this step
to prevent the formation of local zones of alkalinity.
Periodically, small aliquots of the reaction mixture were
withdrawn and tested for reducing sugar content. ~pproxi-
mately 400 grams of the 2.5~ sodium amalgam were needed
to produce the maximum quantity of reducing sugar. After
the addition of the sodium amalgam, the aqueous phase was
decanted from the mercury, filtered and hot ethanol added
with stirring to bring the final concentration to 85%.
The precipitated sodium sulfate was removed by filtration
and the filtrate concentrated to about 50 ml. at reduced
pressure and at a temperature less than 45~. This fil-
trate was poured through a pad of activated carbon and then
titrated with a one-half saturated solution of barium
9~
hydroxide using phenolphthalein as an indicator. The re-
action mixture was poured into ten volumes of hot, absolute
ethanol and the resulting barium L-allonate, which is in-
soluble in 93% ethanol, was filtered. The filtrate was
evaporated under reduced pressure to a thin syrup and
allowed to crystallize. Crystals were separated by filtra-
tion, the filtrate and washings were concentrated to a thin
syrup and an additional crop of ~-L-allose was obtained
upon storage~in a desicator. This gave a yield of about
70%. Recrystallization was effected from hot 93% ethanol
to yield pure crystals, m.p. 128-129C.
Example 3
~-L-Fructose Hemih~drate
l-Deoxy-l-diazo-keto-L-fructose tetracetate
A solution of 14 grams of tetra-O-acetyl-L-
arabinoyl chloride ~Wolfrom and Thompson, J. Am. Chem.
Soc., 68 791 (1961)] in 200 ml. of absolute ether was
added slowly to a solution of 4.2 grams of diazomethane
in 500 ml. of absolute ether. The resulting solution
was allowed to stand ~or about two hours at room temperature
and then concentrated approximately to one-third its vol-
ume. The product was crystallized by the addition of
petroleum ether with cooling and yielded about 10 grams
(65~ yield) of crude product. Pure product was obtained
by recrystallization from absolute ethanol, melting point
93-94C.
Keto-L-fructose pentacetate
A solution of 10 grams of l-deoxy-l-diazo-
keto-L-fructose tetracetate and 0.01 gram of cupric acetate
_ g _
~,~ sa~
in 300 ml. of anhydrous acetic acid in a 2 liter flask
was heated gently and after the initial violent evolu-
tion of gas had subsided, was brought just to the
boiling point. The solvent was removed by distillation
under reduced pressure, the final portion was removed by
distillation with ethanol. The resulting syrup was dis-
solved in 15 ml. of ethanol, filtered and allowed to
crystallize overnight in a refrigerator. This yielded 4
grams of crystals, m.p. 65C. The syrup obtained from
mother liquid was dissolved in 50 ml. of acetic anhydride
containing 0.5 gram of zinc chloride (fresh fused), allowed
to stand overnight at room temperature and heated 90
minutes at 50C. Excess acetic anhydride was hydrolyzed
by pouring into 200 ml. of ice-water and stirred for 2
hours. The acetylated sugar was extracted from the water
with 200 ml. of chloroform. The chloroform solution was
washed with water, dried over anhydrous sodium sulfate,
filtered and evaporated to a syrup. This syrup was
crystallized from 10 ml. of ethanol and yielded an addi-
tional 3 grams of product.
~-L-fructose hemihydrate
Ten grams of finely powdered keto-L-fructose
pentacetate was added to 135 ml. of an aqueous solution
of 13 grams of barium hydroxide octahydrate at 0C. This
mixture was stirred at this temperature for about 30 min-
utes at which time all of the pentacetate was dissolved,
and then allowed to stand for an additional 90 minutes
at this temperature. A solution of 3 grams of oxalic acid
-- 10 --
in 25 ml. of water was added to precipitate most of the
barium ions. The remainder of the barium ions were removed
by stirring the filtered solution with excess of ,~mberlite
IR-100(H+) cation-exchange resin until the solution no
longer gave a positive test for barium ions with sulfate.
The resin was removed by filtration and the solution was
stirred with Duolite A-4(OH ) anion-exchange resin until
the pH increased to the range of 6.8 to 7. The resin was
filtered off~and the solution concentrated under reduced
pressure at a temperature below 50C. The resulting syrup
was crystallized from ethanol at refrigerator temperature
to yield about 4 grams of`product. This was recrystallized
as ~-L-fructose hemihydrate by dissolving in a small amount
of water, evaporating under reduced pressure and dis-
solving the syrup in ethanol; melting point 101-103C.
Example 4
L-Gulose
2,4-0-Benzylidene-6-deoxy-6-nitro-D-glucitol
A solution of 53.7 grams of syrupy 2,4-0-benzyl-
idene-L-xylose [Fischer and Piloty, Ber. 24 52 (1891)] in
one liter of absolute methanol and 160 ml. of nitromethane
was treated with a solution of 10 grams of metallic sodium
in 800 ml. of absolute methanol for 22 hours at room tem-
perature. The reaction mixture was acidified with a slight
excess of glacial acetic acid and concentrated under reduced
pressure. Methanol and nitromethane were remo~ed by the
addition of water and further concentrated under reduced
pressure. The moist crystalline mass was mixed with cold
~ t~ ~ "/~ k
-- 11 --
~0C.) water, filtered and washed with cold ~0C.) water.
~his yielded 34 grams (50% yield) o~ crude 2,4-0-benzyl-
idene-6-nitro-D-glucitol, m.p. 178-181C.; recrystallization
gave a purer product, m.p. 192-194C.
6-Deoxy-6-nitro-D-glucitol
Ten grams of 2,4-benzylidene-6-deoxy-6-nitro-D-
glucitol was heated for one hour at 75-80C. with 100 ml.
of 0.lN H2SO4'. After cooling the solution was extracted
three times with ether to remove the benzaldehyde and
neutralized with excess barium carbonate. The barium
carbonate and barium sulfate were removed by centrifuga-
tion and ~iltration through a precoated filter. The clear
solution was then concentrated under reduced pressure to
a syrup, which crystallized spontaneously after standing
several days. This product was recrystallized from ethyl
acetate containing a little methanol and yielded 5.6 grams
(79% yield) of 6-deoxy-6-nitro-D-glucitol, m.p. 78-80C.
On recrystallization from dry ethyl acetate, there were
obtained soft needles, m.p. 81-83C., and hard compact
prisms, m.p. 89-91C.
L-Glucose Benzylphenylhydrazone
~ syrup of 6-deoxy-6-nitro-D-glucitol which was
obtained by the hydrolysis of 13.6 grams of 2,4-benzyl-
idene-6-deoxy-6-nitro-D-glucitol was dissolved in 55 ml. of
lN sodium hydroxide. This solution was added dropwise to
20 ml. of vigorously stirred sulfuric acid solution (60%
weight/weight). The acidic solution was then diluted with
- 12 -
water and neutralized with excess barium carbonate, 4 ml.
of acetic acid were added and the barium sulfate was re-
moved by filtration. The clear filtrate was concentrated
under reduced pressure to a syrup which was dissolved in
100 ml. of 75% ethanol. The ethanolic solution was fil-
tered and treated with about 10 grams of l-benzyl-l-phenyl-
hydrazine. This solution was allowed to evaporate in an
open dish with the occasional addition of small amounts of
methanol, until crystallization was complete. The
crystals were freed from the syrup by washing with water
and then ether. This yielded 8.5 grams (67% yield) of
crude L-gulose benzylphenylhydrazone, m.p. 124-128C.
This was recrystallized from a solution of 110 ml. of chloro-
form and 15 ml. of methanol to give colorless L-gulose
benzylphenylhydrazone, m.p. 130-131C.
L-Gulose
The L-gulose benzylphenylhydrazone was refluxed
for three hours with 100 ml. of water and 20 ml. of ethanol
containing 7.5 ml. of benzaldehyde and 0.8 gram of benzoic
acid. After cooling, the solution was decanted from the
crystals of benzaldehyde benzylphenylhydrazone and ex-
tracted several times with ether to remove the benzalde-
hyde and benzoic acid. The solution was then decolorized
with activated carbon and concentrated under reduced pres-
sure to a colorless syrup to yield 3.4 grams of syrupy L-
gulose.
- 13 -
Example 5
a-1-Galactose
L-Galactono-1,4-lactone
A solution of 21.6 grams (0.1 mole) of sodium
D-galacturonate [Molten, et al, J. Am. Chem. Soc., 61 270
(1939); Pigman, J. Research Natl. Bur. Standards, 25 301
(1940); Isbell et al, ibid, 32 77 (1944)] in 200 ml. of
water was placed in a 500 ml. flask and cooled in an ice
bath. With stirring, 100 ml. of cold, freshly-prepared
0.5 M. aqueous solution of sodium borohydride (100%
j excess) was added and the reduction mixture allowed to
stand overnight at about 5C. It was then stirred with
25 ml. of cation-exchange resin, Amberlite I.R.-120(H+)
to decompose unreacted sodium borohydride, and then
poured through a column containing 250 ml. of resin. The
effluent and washings were concentrated under reduced pres-
sure to a syrup. Methanol was added to the syrup and
this mixture warmed under reduced pressure to remove the
boric acid as methyl borate. This procedure was repeated
two times. The residue was then heated with 25 ml. of
Methyl Cellusolve (2-methoxyethanol) on a boiling water
bath for two hours. Isopropanol was added almost to the
point of incipient turbidity and the solution seeded with
crystalline L-galactono-1,4-lactone. Crystals of L-
galactono-1,4-lactone were separated. Concentration of
the mother liquor and addition of isopropanol gave more
crystalline lactone. Recrystallization from hot ethanol
gave about a 90% yield of crystalline L-galactono-1,4-
lactone, m.p. 13~C.
t-rs~e r~1 a~ks
-- 14 --
~ 5~
L-Galactose
A mixture of 500 ml. of finely crushed ice, 115
grams of sodium hydrogen oxalate and 10 grams of L-galac-
tono-1,4-lactone was agitated in a closely covered, high
speed blender with stainless steel blades. After a few
seconds of blending, 260 grams of pellets of 5% sodium-
amalgam was gradually added and agitation was continued
for 15 minutes, during which time the temperature rose to
about 30-35C. The resulting solution was decanted from
the mercury and neutralized with dilute sodium hydroxide
until a faint but permanent pink color of phenolphthalein
was obtained. This solution was evaporated under reduced
pressure to a volume of about 100 ml. and treated with five
volumes of methanol. The precipitated salts were separated,
washed with a little methanol and discarded. The filtrate
was concentrated under reduced pressure to about 50 ml.
and again treated with five volumes of methanol. The pre-
cipitated salts were again removed by filtration and the
solution after concentration to about 50 ml. was deionized
by passage through a column containing 60 ml. of mixed
cation and anion exchange resins, Amberlite I.R.-120(H+)
and Duolite A 4(OH ). The combined effluent and washings
were tested for ionic impurities by means of a conductivity
meter and, when free of ionic impurities, concentrated
under reduced pressure to a thin syrup. This syrup was
dissolved in a minimal amount of methanol and isopropanol
added to the point of incipient turbidity. The crop of
crystals was separated and washed with methanol, and an
additional crop of crystals obtained from the mother
.
- 15 -
liquor by concentration and addition of methanol to
give a total yield of about 80%.
Organoleptic tests were conducted to determine
the sweetening power of the L-hexoses. Exemplary of these
is the following conducted with D-glucose, L-glucose and
sucrose (common sugar), wherein distilled water solutions
of both D-glucose and sucrose in concentrations of 1 mg./
ml., 10 mg./ml. and 100 mg./ml. were prepared. Each of
these solutidns was divided into three parts and each
tested by a panel of three tasters. Each member of the
panel sampled each of the two solutions at the three
different concentrations, with appropriate rinsing of
their mouths after each taste. The panel had previously
been instructed to rate each of the samples on the basis
of 0 to 3, the 0 indicating no sweetness and the 3 indi-
cating the highest degree of sweetness. The panel was in
agreement that a substantial degree of sweetness, i.e., in
the range of 2-3, was not attained by either the D-glucose
or sucrose until the more concentrated, i.e., 100 mg./ml.,
solutions were tasted. This same panel was used to taste
test solutions of L-glucose at a concentration of 100 mg./
ml. using the same procedure. Again, the panel was in
agreement that the L-glucose solution was sweet and a
substantial degree of sweetness, i.e., a 2-3 rating, was
~btained with the 100 mg./ml. solutions of L-glucose.
Similar results were obtained with the other L-hexose
monosaccharides of this invention. Thus, the minimum
concentration of L-hexose necessary to obtain a substan-
tial degree of sweetness is about 100 mg./ml.
- 16 -
,t
1~'
~.
~56~9~
The above examples are indicative of the
methods which may be used to obtain the L-hexose monosac-
charides used in the present invention. Obviously, other
preparation methods may be employed to obtain the subject
L-hexoses used as sweetening agents within the scope of
the present invention. Other 2-aldohexoses which may be
used according to this invention as sweetening agents to
prepare edible food formulations include L-alose, which
may be prepa~ed from L-arabinose via the intermediate
formation of L-ribose and L-altronic acid [Austin et al,
J. Am. Chem. Soc., 56 1153 (1934)], L-idose, which may be
prepared from D-glucose [Meyer et al, Helv. 29 152 tl946)],
and L-talose, which may be prepared according to the pro-
cedure of Stallhaar and Reichstein, Helv. 21 3 (1938)].
Other L-ketohexoses which may be used as sweetening agents
include L-tagatose, which may be prepared by the alkaline
rearrangement of L-sorbose and L-psicose, which may be
prepared by the oxidation Eermentation of allitol by sorbose
bacterlum [Steiger et al, Helv. 1~ 790 (1935)].
Other commonly known and employed preparative
methods may be used to prepare the L-hexose monosaccharides
of the present invention. Discussions of such methods may
be found in the literature of carbohydrate chemistry. For
example, one general method of preparing hexoses is based
upon the lenythening of the carbon-to-carbon chain, i.e.,
preparation of hexoses from the corresponding pentose.
Under this general method are procedures such as the
cyanohydride synthesis ~Kiliani-Fischer method), nitro-
methane synthesis (Sowden-Fischer method), and diazo-
methane synthesis, and each of these are useful in the
- 17 -
i preparation of the subject hexoses. Another general
method involves a shortening of the carbon-to-carbon chain,
i.e., preparation of hexoses from the corresponding
heptose. Under the general method are procedures such
as the Ruff degradation, the Wohl degradation, the Weeman
degradation, the MacDonald-Fischer degradation and the
Weygand-Lowenfeld degradation and each of these are useful
in the preparation of the subject L-hexoses. Another
general method involves changing the configuration of the
corresponding saccharide. Thus, procedur~es such as the
pyridine and alkaline rearrangement and glycol synthesis
are useful. Discussions of the methods may be found in
W. Pigman, The Carbohydrates, pages 106-132 (Academic
Press, New York, 1957), and the references cited therein.
As has been discussed above, the term L-hexose
monosaccharides as used herein and in the appended claims
is used within the standard meaning in the art. Thus, the
Prefix "L" refers to the configuration of the hexose
structure according to the Fischer system of nomenClature
as modified by Roranoff. According to this system, the
subject L-hcxoses are considered to be those derived from
the fundamental structural glycerose, L-glyceraldehyde of
the formula:
`' CHO
HO-C-H
I
H2C OH
by the successive application of the cyanohydrin synthesis
to obtain a hexose. These compounds are configurationally
the direct opposite of those hexoses derived by the same
t- 18 -
- 1 .
~, .
series of reactions, from the fundamental structural
glycerose, D-glyceraldehyde of the formula:
CHO
H-C-OH
H C-OH `
Similarly, the subject L-ketohexoses are,
according to this system, derived from the fundamental
L-ketose, L-erythrulose (L-threulose) of the formula:
C=O
HO-C-H
CH2H
A further discussionof this terminology may
be found in W. Pigman, The Carbohydrates, pages 21-29
(Academic Press, New York, 1957) and the references
cited therein. It is, of course, to be understood that
while the configuration of the L-hexoses, in particular
the L-glucose, has been shown structurally in an open
chain of Fischer projection type formula, it is equally
within the scope of this invention that the L-hexoses
may have a xing structure, for example, a pyranose or
furanose ring, with the L-configuration, and still be
useful as a sweetening agent for edible formulations.
As has been discussed above, the L-hexose mono-
saccharides are sweet, soluble in water and stable in
aqueous solutions. Therefore, they are useful for
sweetening all types of materials which are intended
for consumption or at least contact with the mouth of
- 19 -
~5~3~9~
the user, such materials being herein generically desig-
nated as edible materials or foodstuffs. Typical
illustrative examples of edible foodstuffs which may
be sweetened according to this invention are fruits,
vegetables, juices or other liquid preparations made
from fruits or vegetables, meat products, particularly
those conventionally treàted with sweetened liquors, such
as bacon and ham, milk products such as chocolate dairy
drinks, egg products, such as egg nogs, custards, angel
food mixes, salad dressings, pickles and relishes, ice
creams, sherberts and ices, ice milk products, bakery
products, icings, confections and confection toppings,
syrups and flavors, cake and pastry mixes, beverages, such
as carbonated soft drinks, fruit aids, wines, dietary-
type foods, cough syrups and other medicinal preparations
such as pastes, powders, foams and denture-retaining ad-
hesives, mouth washes and similar oral antiseptic liquids,
tobacco products, adhesives for gumming stamps, envelopes,
labels and the like.
In using the swectening agents of this inven-
tion, they are incorporated in the material to be sweetened
in the amoun-t required to attain the desired level of
sweetness. It is obvious that there is nothing critical
about the concentration of sweetening agent which is
used. It is simply a matter of attaining a desired sweet-
ness level appropriate to the material in question.
Moreover, the technique of sweetening materials with the
compounds of the invention offers no difficulty as the
sweetening agent is simply incorporated with the material
,
- 20 -
-
to be sweetened. The sweeteners may be added directly to
the material or they may be first incorporated with a di-
luent to increase their bulk and added to the material.
As diluent, if needed, one may use liquid or solid
carriers, such as water, glycol, starch, sorbitol, salt,
.
citric acid or other non-toxic substances compatible with
the material to be sweetened.
While the invention has been described as mainly
concerned with foodstuffs and other non-toxic formulations
for human consumption, it is obviously wlthin the scope of
this invention that these sweetened compositions may be
used for consumption by other animals, such as farm and
domestic animals.
While the invention has been described with
respect to the use of L-hexose monosaccharides as the sole
sweetening agent, it is to be understood that they may be
used in combination with conventionally us~d sweetening
agents, e.g., in combination with a minor amount of
sucrose.
