Patent Description:
The present invention relates to sweetening compositions containing steviol glycosides, salts, and other natural or synthetic sweeteners with improved solubilities and sensory profiles.

The stems and leaves of Stevia rebaudiana contain a group of diterpene glycosides, called "steviol glycosides", some of which are up to <NUM> times sweeter than table sugar (sucrose), depending upon the sucrose equivalence (defined below) required for a given food, beverage, or other comestible. Many steviol glycosides have been isolated and identified, and include, but are not limited to: rebaudioside A ("Reb A" or "RA"), rebaudioside B ("Reb B" or "RB"), stevioside ("STV"), steviol bioside ("STB"), rebaudiosides C, D, E, and F, rubusoside, and dulcoside A. All of these compounds are sweet; however, at commonly used sucrose equivalencies, all but pure rebaudioside A also have a bitter in-mouth taste (taste while a test substance is in the buccal cavity) and bitter aftertaste (lingering taste after swallowing or expectoration of the test substance). Reb A has a clean sweet taste and, at purities greater than <NUM>% and at commonly used sucrose equivalencies, has none of the in-mouth bitterness and bitter aftertaste associated with the other steviol glycosides. Reb A can be produced in various purities using, inter alia, the process described by Jackson in <CIT> (<CIT>, issued as <CIT>).

Blends of various purities of rebaudioside A can be used as sweeteners. The higher the RA content of a sweetener, the more expensive the sweetener is. Blending various purities of rebaudioside A produces sweeteners at selling prices corresponding to the RA purity of the ingredients: the higher the RA purity of the ingredients, the higher the selling price of the blended sweetener. Various sweetener compositions are known. <CIT> describes a sweetener composition comprising at least one natural high-potency sweetener, at least one modified natural high-potency sweetener, or combinations thereof, and at least one sweet taste improving composition. <CIT> describes glucosyl stevia compositions prepared from steviol glycosides of Stevia rebaudiana Bertoni. <CIT> describes methods of purifying Rebaudioside D from the Stevia rebaudiana Bertoni plant extract along with Rebaudioside A. The methods are useful for producing high purity Rebaudioside D and Rebaudioside A and products containing the purified Rebaudioside D. <CIT> describes a natural sweetener composition comprising a blend of Stevioside extract and Rebaudioside A extract, wherein the ratio of Rebaudioside A extract to Stevioside extract is between about <NUM>:<NUM> to about <NUM>:<NUM>. <CIT> describes glycoside blends comprising any or all of rebaudioside A, rebaudioside B, and rebaudioside D together with stevioside in various proportions. <CIT> and <CIT> describe stevia compositions which are prepared from steviol glycosides of Stevia Rebaudiana Bertoni. <CIT> describes sweetening compositions comprising selected amounts of rebaudioside B.

Liquid sweeteners are required for beverage production and for many food products at commercial scale. Some countries have a strong preference for liquid table top sweeteners, e.g., South American and Asian countries. Non-caloric and low caloric natural, "high intensity" sweeteners are in high demand for use in non-caloric or reduced-caloric foods and beverages, but widespread adoption of sweeteners containing RA and/or STV has been hindered by two factors: (<NUM>) the solubility of Reb A and STV are proportional to the Reb A or STV content of the sweetener, and (<NUM>) the sensory profile of steviol glycosides differs significantly from that of sucrose in, inter alia, slow temporal decay of sweetness, and "thin" mouth feel; moreover, purities of Reb A lower than RA97 and any purity of STV typically have a bitter aftertaste at sucrose equivalencies used in foods and beverages. This means that the more soluble a known Reb A or STV sweetener is, the worse it can taste. The problems with solubility of known Reb A and STV compositions are described have been disclosed in the art (<NPL>.

RA50 (RA50 is a product comprising ><NUM>% RA, and ><NUM>% total steviol glycosides) powder dissolves easily in water at <NUM>, but the solubility of RA97 (RA97 is a high purity RA product comprising ><NUM>% RA) under the same conditions is only <NUM>%. The higher the purity Reb A or STV, the faster it precipitates out of solution. A concentration of RA97 any higher than <NUM>% rapidly precipitates out of solution. High purity STV also exhibits a similar phenomenon of very low solubility, and rapid precipitation out of solution. Two illustrations show the solubility barrier now existing in the art of Reb A and STV sweeteners. For soft drink dispensing equipment designed for an sucrose equivalent (SE - a measure of sweetness) of <NUM>, using a syrup that has an SE of <NUM> would increase the volume of the syrup by a factor of <NUM> to reach an SE of <NUM> in a dispensed beverage. Increasing the volume of syrup by a factor of <NUM> would be uneconomic, and also impractical for small volume goods. In countries that prefer liquid table top non-sucrose (aka "artificial") sweeteners, two drops of liquid sweetener provide the sweetness of a teaspoon of sugar (<NUM> grams). However, two drops (<NUM>µL) of RA97 sweetener (assuming RA97 is 300x sweeter than sucrose) only provides an SE of <NUM> grams of sucrose rather than an SE of <NUM> grams of sucrose. Known Reb A-based liquid sweeteners have failed commercially because they cannot provide adequate sucrose equivalencies. Ideally, if the solubility problem were overcome, the liquid sweetener could be dried and used as a dry (powdered, agglomerated, or granulated) sweetener.

The sensory profile problem that has impaired commercial acceptance of Reb A and STV sweeteners is typically addressed by using masking agents if lower purity (and more soluble) Reb A or STV is used, or by using higher purity Reb A and STV in much lower volume, as a flavor rather than as a sweetener. Ideally, overcoming the solubility problem would also provide a natural sweetener with an improved sensory profile.

The invention is as set out in the appended set of claims. The technical problems to be solved are to provide substantially improved solubility of higher purity Reb A and/or STV, higher sucrose equivalence of liquid Reb A and STV sweeteners, a dried form of such improved RA and STV compositions that retains high solubility when re-dissolved, and improved sensory profiles of such improved RA and STV compositions.

The composition or sweetener of the invention includes one or more steviol glycosides, one or more salts, and one or more natural or synthetic sweeteners. The one or more steviol glycosides include rebaudioside A and rebaudioside B, and can further be selected from steviolbioside, stevioside, rebaudioside C, rebaudioside D, rebaudioside E, rebaudioside F, rubusoside, dulcoside A, and rebaudioside M. The one or more salts can be selected from any salt that is edible, including but not limited to sodium chloride, potassium chloride, magnesium chloride, sodium sulfate, magnesium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, magnesium carbonate, sodium bicarbonate, and potassium bicarbonate. The one or more natural or synthetic sweeteners are selected from sucrose, fructose, maltose, lactose, xylitol, sorbitol, dextrose, glucose, mannitol, aspartame, sucralose, acesulfame-K, sodium cyclamate, inulin, erythritol, thaumatin, arabinose, glatactose, mannose, rhamnose, xylose, trehalose, raffinose, cellobiose, tagatose, allulose, and mogroside. In some aspects the composition or sweetener is prepared by hydrolysis of a raw material containing rebaudioside A. The raw material containing rebaudioside A can contain ><NUM> wt. % rebaudioside A, ><NUM> wt. % rebaudioside A, or ><NUM> wt. % rebaudioside A. In other aspects the composition can be prepared by hydrolysis of a raw material containing stevioside. The raw material containing stevioside can contain ><NUM> wt. % stevioside, ><NUM> wt. % stevioside, or ><NUM> wt. % stevioside.

The composition or sweetener includes both rebaudioside A and rebaudioside B. Rebaudioside A comprises <NUM>-<NUM> wt. % of total steviol glycosides in the composition or sweetener. Rebaudioside B comprises greater than <NUM> wt. % to <NUM> wt. % of total steviol glycosides in the composition or sweetener. The composition or sweetener can include rebaudioside B having greater than <NUM> wt. % to <NUM> wt. % of the composition or sweetener. The composition or sweetener can include a salt having from <NUM> wt. % to <NUM> wt. % of the composition or sweetener. The composition or sweetener can include a natural or synthetic sweetener having from <NUM> wt. % to <NUM> wt. % of the composition or sweetener. The composition or sweetener can also include rebaudioside A and rebaudioside B having about <NUM>% of total steviol glycosides in the composition or sweetener.

In one aspect the composition or sweetener has increased solubility compared to the same composition or sweetener without one or more salt, has increased solubility compared the same composition or sweetener without one or more natural or synthetic sweeteners, and has increased solubility compared the same composition or sweetener without one or more salt and one or more natural or synthetic sweeteners. In another apect the composition or sweetener has improved sensory profile compared to the same composition or sweetener without one or more salt, has improved sensory profile compared to the same composition or sweetener without one or more natural or synthetic sweeteners, and has improved sensory profile compared to the same composition or sweetener without one or more salt and one or more natural or synthetic sweeteners. The composition or sweetener can include Rebaudioside A, Rebaudioside <NUM>, glucose, and sodium chloride having about <NUM> wt. % to about <NUM> wt. % of Rebaudioside A, <NUM> wt. % to about <NUM> wt. % of Rebaudioside B, greater than <NUM> wt. % to about <NUM> wt. % of glucose, lactose, galactose, or maltose, and from greater than <NUM> wt. % to about <NUM> wt. % of sodium chloride or potassium chloride. In a preferred aspect the Rebaudioside A, Rebaudioside B, glucose, and sodium chloride includes a weight ratio of <NUM>:<NUM>:<NUM>:<NUM> respectively.

Also disclosed are methods to prepare the composition or sweetener of the embodiments disclosed above.

In the specification and in the claims, the terms "including" and "comprising" are open-ended terms and should be interpreted to mean "including, but not limited to. " These terms encompass the more restrictive terms "consisting essentially of" and "consisting of.

It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. As well, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. It is also to be noted that the terms "comprising", "including", "characterized by" and "having" can be used interchangeably.

Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications and patents specifically mentioned herein may be referred to for all purposes including describing and disclosing the chemicals, instruments, statistical analyses and methodologies which are reported in the publications which might be used in connection with the invention. All references cited in this specification are to be taken as indicative of the level of skill in the art. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

The phrase "stevia starting material" or "raw material" means a material containing steviol glycosides of the plant Stevia rebaudiana or other species of Stevia genus. The stevia starting material or raw material can be a crude extract, a purified extract, or a byproduct of a purification process. A crude extract is typically the first dried product produced after processing harvested Stevia plant material. A purified extract contains a higher concentration of one or more steviol glycosides of interest than contained in a crude extract. A byproduct of a purification process typically is all or a portion of the waste stream from purifying steviol glycosides from crude extract or from an intermediate purity.

The acronym "RAxx" is used herein to denote a purity of Rebaudioside A final product isolated from crude extract of Stevia, where "xx" is a number between <NUM> and <NUM> and is the percentage of Rebaudioside A in the dried product. More generally, acronyms of the type "YYxx" are used herein to denote the purity of a given ingredient denoted by the placeholder "YY", as a mass percentage of a compound, where "xx" is a number between <NUM> and <NUM> and is the percentage of product YY in the product. For instance, a compound that is <NUM>%, steviol glycosides ("SG") would be denoted "SG95", and a compound that is <NUM>% stevioside ("STV") would be denoted "STV97". A product of that is <NUM>% Rebaudioside A would be denoted "RA97". Denoted percentages include a range of approximately <NUM>% above and below a whole number percentage, unless otherwise indicated. For instance, "<NUM>% or higher purity Reb A" would include purity between <NUM>% Reb A and RA100, whereas "RA97" would include a range of <NUM>% to <NUM>%. "RA99+" means greater than <NUM>% purity Reb A. "Pure Reb A" is denoted as RA100, and is defined in <CIT>.

The phrase "steviol glycosides" is recognized in the art and is intended to include the major and minor constituents of stevia. These include, but are not limited to components of stevia such as Steviol, Steviolbioside, Stevioside, Rebaudioside A (RA), Rebaudioside B (RB), Rebaudioside C (RC), Rebaudioside D (RD), Rebaudioside E (RE), Rebaudioside F (RF), Rubusoside and Dulcoside A (DA).

The phrase "stevia containing sweetener" is intended to include any composition that is prepared from a stevia plant, such as a stevia extract, or the individual components found in stevia. The sweetener can include one or more of the components associated with the stevia plant, such as those noted above.

A "stevia composition" as referred to herein, pertains to a material that includes one or more steviol glycosides found in the stevia plant.

The phrase "sucrose equivalence" is the amount of non-sucrose sweetener required to provide the sweetness of a given percentage of sucrose in the same food, beverage, or solution. For instance, a non-diet soft drink typically contains <NUM> grams of sucrose per <NUM> of water, i.e., <NUM>% sucrose. This means that to be commercially accepted diet soft drinks must have the same sweetness as a <NUM>%) sucrose soft drink, i.e., a diet soft drink must have <NUM>% sucrose equivalence ("SE"). Soft drink dispensing equipment assumes an SE of <NUM>%, since such equipment is set up for use with sucrose-based syrups.

The phase "sensory profile" is defined as the temporal profile of all basic tastes of a sweetener. The onset and decay of sweetness when a sweetener is consumed, as perceived by trained human tasters and measured in seconds from first contact with a taster's tongue ("onset") to a cutoff point (typically <NUM> seconds after onset), is called the "temporal profile of sweetness". A plurality of such human tasters is called a "sensory panel". In addition to sweetness, sensory panels can also judge the temporal profile of the other "basic tastes": bitterness, saltiness, sourness, piquance (aka spiciness), and umami (aka savoriness or meatiness). The onset and decay of bitterness when a sweetener is consumed, as perceived by trained human tasters and measured in seconds from first perceived taste to the last perceived aftertaste at the cutoff point, is called the "temporal profile of bitterness".

The term "flavor" or "flavor characteristic", as used herein, is the combined sensory perception of the components of taste, odor, and/or texture. The term "enhance", as used herein, includes augmenting, intensifying, accentuating, magnifying, and potentiating the sensory perception of a flavor characteristic without changing the nature or quality thereof. The term "modify", as used herein, includes altering, varying, suppressing, depressing, fortifying and supplementing the sensory perception of a flavor characteristic where the quality or duration of such characteristic was deficient.

The technical problems are solved by the invention disclosed and claimed herein.

While not to be bound by theory, the inventors have discovered the unexpected result when one or more steviol glycosides, whether prepared by hydrolysis or not, are combined with one or more salts and one or more natural or synthetic sweeteners have improved solubility and sensory profiles.

By combining steviol glycosides, including all possible combinations of the steviol glycosides disclosed herein, with one or more salts and one or more natural or synthetic sweeteners in a composition results in improved solubility and sensory profile as described and can be used as a sole sweetener of food, beverage, medicine, tobacco, pharmaceutical, and personal care products.

The one or more steviol glycosides include rebaudioside A and rebaudisoide B, and can further include steviolbioside, stevioside, rebaudioside C, rebaudioside D, rebaudioside E, rebaudioside F, rubusoside, dulcoside A, and rebaudioside M.

The one or more steviol glycosides contained in the sweetening composition can make up anywhere from about <NUM> wt. % of the sweetening composition to about <NUM> wt. % of the sweetening composition, specifically about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, and all ranges therebetween, including for example from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to about <NUM> wt.

The sweetening composition includes one or more natural or synthetic sweeteners selected from sucrose, fructose, maltose, lactose, xylitol, sorbitol, dextrose, glucose, mannitol, aspartame, inulin, sucralose, acesulfame-K, sodium cyclamate, erythritol, thaumatin, arabinose, galactose, mannose, rhamnose, xylose, trehalose, raffinose, cellobiose, tagatose, allulose, and mogroside.

The composition can also include conventional sweeteners (cane sugar, beet sugar, honey, syrups, sucrose, fructose, maltose, xylitol, sorbitol, dextrose, glucose, mannitol, arabinose, galactose, mannose, rhamnose, xylose, and other "natural" sweeteners) and artificial or synthetic sweeteners (cyclamates and salts thereof, saccharin and salts thereof, sucralose, aspartame, a stevia composition, acesulfame-K, neotame, thaumatin, erythritol, trehalose, raffinose, cellobiose, tagatose, DOLCIA PRIMA™ allulose, inulin, N--[N-[<NUM>-(<NUM>-hydroxy-<NUM>-methoxyphenyl)propyl]-alpha-aspartyl]-L-phenylalanine <NUM>-methyl ester (hereinafter abbreviated as "ANS9801"), glycyrrhizin, thaumatin, monellin and other chemically produced high-intensity sweeteners). Alternatively, the composition can also include any substance that has a sweet taste.

The one or more natural or synthetic sweeteners in addition to the steviol glycosides of the sweetening composition make up anywhere from <NUM> wt. % of the sweetening composition to <NUM> wt. % of the sweetening composition, specifically <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, <NUM> wt. %, and all ranges therebetween, including for example from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to <NUM> wt.

The sweetening composition of the invention includes one or more salts. The one or more salts can include sodium carbonate, sodium bicarbonate, sodium chloride, potassium chloride, magnesium chloride, sodium sulfate, magnesium sulfate, and potassium sulfate, or any edible salt, for example a metal or metal alkali halide, a metal or metal alkali carbonates, bicarbonates, a metal or metal alkali phosphates, biphosphates, pyrophospate, triphosphate, metaphosphate, a metal or metal alkali sulfate or metabisulfate.

The one or more salts make up anywhere from <NUM> wt. % of the sweetening composition to <NUM> wt. % of the sweetening composition, specifically <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. %, about <NUM> wt. % , about <NUM> wt. %, about <NUM> wt. %, <NUM> wt. %, and all ranges therebetween, including for example from <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to about <NUM> wt.

All of the components of the sweetening composition can be purchased or be made by processes known to those of ordinary skill in the art and combined (e.g., precipitation/co-precipitation, mixing, blending, grounding, mortar and pestal, microemulsion, solvothermal, sonochemical, etc.).

In one aspect, Rebaudioside A can be hydrolyzed to lyse a glucose unit from the glycoside chain on the C13 carbon of Reb A, which converts Reb A to Reb B. Stevioside can be hydrolyzed to lyse a glucose unit from the glycoside chain on the C13 carbon of stevioside, which converts STV to STB. The inventors discovered the unexpected result that the solubility and sensory profile of the products of hydrolysis (RA and RB, and STV and STB) is improved compared to plain mixtures of RA and RB, and STV and STB, made from purified RA and RB, and purified STV and STB, starting materials. While not to bond by theory, the inventors believe that the results are due to the glucose and salts generated in the hydrolysis process, i.e. the hydrolysate is a composition comprising additional components, in addition to RA. and RB, and thus is different from the plain mixture. In other words, if the same molar concentration of purified Reb A and Reb B are mixed and dissolved, the Reb A and Reb B rapidly precipitate out of solution. The hydrolyzed RA/RB, and hydrolyzed STV/STB, stays in solution. For clarification purposes, "RA/RB" means the products of alkaline hydrolysis of Reb A and "STV/STB" means the products of alkaline hydrolysis of STV.

In one aspect Rebaudioside A can be hydrolyzed to lyse a glucose unit from the glycoside chain on the C13 carbon of Reb A, which converts Reb A to Reb B, and thus the mole ratio of rebaudioside B and glucose is about <NUM>:<NUM>.

Alkaline hydrolysis of the starting or raw material is preferred for simplicity and economics. Enzymatic lysis of a glucose unit from the C13 carbon of Reb A or STV can also be used. Sodium hydroxide is the preferred alkali to use for hydrolysis of Reb A and STV, but potassium hydroxide and other well-known alkali used in food processing can be used.

The starting or raw materials can include ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, ><NUM> wt. % of rebaudioside A or stevioside, or ><NUM> wt. % of rebaudioside A or stevioside.

Reb A starting material is dissolved in water (preferably potable water), alkali added, and the solution temperature raised preferably to <NUM> to <NUM>, and more preferably to <NUM>. If the alkaline hydrolysis is conducted at temperatures lower than <NUM>, the reaction proceeds slowly until the alkali is exhausted. The solution is stirred and is maintained at the selected temperature for a duration that provides the desired concentrations of RA and RB in the solution or until the alkali is exhausted. The preferred duration of alkaline hydrolysis at commercial scale is a minimum <NUM> minutes; shorter durations typically do not exhaust the amounts of alkali used in commercial production. The final RA/RB solution is typically very close to pH <NUM>, but pH can be adjusted (typically by adding HCl or NaOH).

The process described above used to produce an RA/RB solution also hydrolyzes any STV present in the stevia starting material to an STV/STB solution.

The RA/RB (and STV/STB) solution produced as described above is brown in color, has a faint "burnt sugar" smell, and has a weak "caramel" taste. The brown color, burnt sugar smell, and caramel taste can be removed by column chromatography such as an activated charcoal column, a polymer resin adsorption column or with an ion exchange column as the chromatography matrix, binding the caramel components to the column while letting the steviol glycosides pass through. Depending upon the beverage, food, or other comestible in which the RA/RB (or STV/STB) is used, the brown color, burnt sugar smell, and caramel taste may be desirable, or unnoticeable, in either case avoiding the need to remove the brown color, burnt sugar smell, and caramel taste.

The inventors' experimental results, including a hydrolysis studies and a sensory profile studies are disclosed herein and reported throughout the Figures following the specification. Many variations of alkaline molarity, Reb A purity, STV purity, and reaction time were tested, as disclosed. Reverse osmosis water was used as the solvent in all of the experiments. Solubility of RA/RB and STV/STB products are a function of alkaline concentration in the hydrolysis step.

The RA/RB, and STV/STB, products can be kept in solution as a syrup ready for distribution as a liquid sweetener, or dried for distribution as a dry sweetener. Drying is by spray-drying, lyophilization, oven drying, and other drying processes well-known in the art of sweeteners.

To modify the perceived sweetness of orally consumable compositions containing the Product, The Product can be modified by the addition of taste modifying moieties, such as galactosides. For instance, β-<NUM>,<NUM>-galactosyl can be substituted on the Product using a β-<NUM>,<NUM>-galactosyl transferase enzyme in reactions known in the art. Such Product modified by one or more functional groups is included in the term "Product".

The term "iso-sweet" as used herein is intended to mean that the subject composition has a sweetness equal to that of sugar.

For use as a co-sweetener, the Product can be used in ways known in the art of sweeteners (e.g., steam, ethanol, or alkanol aerosolized Product vapor-deposited on a co-sweetener) to coat or permeate other solid sweeteners, such granular and powdered sugar and artificial sweeteners, to be mixed as a separate powder with such solid sweeteners, to be co-crystallized with other solid sweeteners, or to be suspended or dissolved in liquid sweeteners, such as corn syrup and honey. Commercially available spray dryers used in the ethanol purge and drying stage of the industrial embodiment can typically be configured to produce a particulate size of Product appropriate for an intended use.

In the art of flavoring foodstuffs and medicinal compositions, there is a continuing need for compositions which can modify and improve the flavor of such materials, because acceptance and demand for foodstuffs and medicinal products is generally related to the sensory perception of them. In the art of flavoring oral hygiene compositions, such as mouthwash and toothpaste, and in the art of flavoring chewing compositions, such as chewing tobacco, snuffs and chewing gum, there is a need to improve the flavor characteristics of such chewing compositions with flavor modifiers or enhancers which are non-cariogenic and do not support the growth of tooth decay producing streptococci, lactobaccilli, or the like. Likewise, there is need to improve the flavor characteristics of smoking compositions.

The term "orally consumable composition" includes foodstuffs, medicinal compositions, smoking compositions, chewing compositions and oral hygiene compositions, including mouthwashes and toothpastes. The term "foodstuff" includes both solid and liquid ingestible materials which usually do, but need not, have a nutritional value and are intended for consumption by man or animal. Representative examples of foodstuff include coffee, teas, herbal teas, baked goods, natural and synthetic flavors, spices, condiments, soups, stews, convenience foods, beverages (both carbonated and non-carbonated), dairy products, candies, vegetables, cereals, fruits, fruit drinks, snacks, cocoa products, chocolates, animal feed, and the like. The term "medicinal composition" includes solids, gases and liquids which are ingestible materials having medicinal value, such as cough syrups, cough drops, medicinal sprays, vitamins, and chewable medicinal tablets. The term "chewing compositions" include chewing tobacco, smokeless tobacco, snuff, chewing gum and other compositions which are masticated and subsequently expectorated. Chewing gum includes compositions which comprise a substantially water-insoluble, chewable gum base, such as chicle or substitutes therefor, including jetulong, guttakay rubber or certain comestible natural synthetic resins or waxes. The term "oral hygiene compositions" includes mouthwashes, mouth rinses, toothpastes, tooth polishes, dentifrices, mouth sprays, and mouth refreshers. The term "smoking composition", as used herein, includes cigarette, pipe and cigar tobacco, and all forms of tobacco such as shredded filler, leaf, stem, stalk, homogenized leaf cured, reconstituted binders, and reconstituted tobacco from tobacco dust, fines, or other sources in sheet, pellet or other forms. "Smoking compositions" also include tobacco substitutes formulated from non-tobacco materials, such as representative tobacco substitutes described in <CIT>, <CIT> and <CIT> and references cited therein.

An orally consumable composition having flavor enhanced or modified by the Product may be provided. The Product can modify or enhance flavor characteristics that are sweet, fruity, floral, herbaceous, spicy, aromatic, pungent, "nut-like" (e.g., almond, pecan), "spicy" (e.g., cinnamon, clove, nutmeg, anise and wintergreen), "non-citrus fruit" flavor (e.g., strawberry, cherry, apple, grape, currant, tomato, gooseberry and blackberry), "citrus fruit" flavor (e.g., orange, lemon and grapefruit), and other useful flavors, including coffee, cocoa, peppermint, spearmint, vanilla and maple.

In accordance with one variation, an orally consumable composition may comprise a Product in an amount effective to sweeten or to modify or enhance the taste, odor and/or texture of the orally consumable composition.

The terminology "amount effective" or "effective amount" means an amount that produces a sensory perception. The use of an excessive amount of a Product will produce sweetness that may not be desired for flavor modification or enhancement, just as too much sugar can be added to a foodstuff or beverage. The amount of Product employed can vary over a relatively wide range, depending upon the desired sensory effect to be achieved with the orally consumable composition and the nature of the initial composition.

The Product can be added to an orally consumable composition by admixing the Product with the orally consumable composition or admixing the Product with a component of the orally consumable composition.

The Product can be used in tobacco and tobacco-related products selected from the group comprising cigarettes, cigars, snuffs, chewing tobacco, other tobacco goods, filters, smoking papers, and other smoking compositions. A smoking composition having a sweetened, enhanced, or modified flavor comprises a smoking filler material selected from the group consisting of tobacco, reconstituted tobacco, non-tobacco substitutes and mixtures thereof, and containing an effective amount of Product. "Containing" means both being included as an ingredient and being adsorbed to a material. In one variation of this embodiment, the smoking composition comprises a filter means containing a Product. The term "filter means", as used herein, includes a smoking device means such as a cigar or cigarette holder having a filtering or flavoring module incorporated therein and includes acetate, cotton, charcoal and other fiber, flake or particle filtering means. In another variation of this embodiment, the smoking composition comprises a wrapper means containing a Product. In one variation of this embodiment of this invention, <NUM> to <NUM> parts by weight of a Product is added to <NUM> parts by weight of the smoking filler material. In a preferred variation of this embodiment of this invention, <NUM> to <NUM> parts by weight of a Product is added to <NUM> parts of a weight of a smoking filler material.

Those skilled in the art of flavoring tobacco understand that the effective amount of the Product added to a smoking composition may depend upon the method in which the Product is added to the smoking composition and to which portion of the smoking composition Product is added. Product can be added directly to the smoking filler material, to the filter means, or to the wrapper means of a smoking composition. Product can be added to a filter means of a smoking composition by any manner known to those skilled in the art of flavoring filter means, including but not limited to, incorporating the Product among the fibers, flakes or particles of a filter means, filling the Product between two or more layers of fibers of a fiber filter means to form a triple filter means, or inserting the Product into a smoking device means, such as a cigarette holder.

It is apparent to those skilled in the art that only a portion of the smoking filler material or filter means need be treated with a Product, since blending or other operations may be used to adjust the final or ultimate smoking composition within the effective or desired ranges of concentration of Product. In addition to Product, other flavorings or aroma additives known in the smoking composition flavoring art may be used with Product and added along with Product to the smoking composition. Representative flavorings used in the smoking composition flavoring art include ethyl acetate, isoamyl acetate, propyl isobutyrate, isobutyl butyrate, ethyl butyrate, ethyl valerate, benzyl formate, menthol, limonene, cymene, pinene, linalool, geraniol, citroneilol, citral, peppermint oil, orange oil, coriander oil, lemon oil, borneol, cocoa extract, tobacco extract, licorice extract and fruit extractives.

The Product, in its purified state after spray drying, is generally a fine powder, having a particle size in the range of about <NUM> to <NUM> microns. Fine powders are difficult to handle and difficult to admix with orally consumable compositions, such as tea leaves, tobacco products, herb leaves, coffees and other orally consumable compositions. Also, generally, only a relatively small amount of Product is used with an orally consumable composition when the Product is used as a flavor modifier or enhancer, sweetener, or co-sweetener.

A process for adding Product to an orally consumable composition may comprise admixing Product with a carrier to form a Product-carrier mixture. Preferred carriers include water, ethanol, other alkanols used in food processing, or mixtures thereof. The Product solution so formed is contacted with an orally consumable composition, and the carrier is removed from the orally consumable composition by evaporation, or otherwise, and the Product residues deposited with the orally consumable composition. This process is particularly useful for adding Product to tea leaves, herbal plant leaves, and other sweeteners, particularly granular sucrose (table sugar).

A liquid filter material, suitable for use with an orally consumable composition, may be prepared with Product. The term "liquid filter", as used herein, refers to a porous or semi-porous filter material used for preparation of an orally consumable composition such as a tea bag, a coffee filter or a filter disk. The term "filter disk" refers to a porous or semi-porous inactive article added to an orally consumable composition for the purposes of acting as a vehicle for the addition of a flavoring or sweetening composition to the orally consumable composition. A process for preparing a liquid filter comprising a filter material and Product is typically by admixing Product with a carrier to form a Product-carrier mixture; contacting the Product-carrier mixture with the filter material; and removing the carrier from the filter material thereby depositing a Product residue on the filter material.

The Product can be used in beverages, broths, and beverage preparations selected from the group comprising carbonated, non-carbonated, frozen, semi-frozen ("slush"), non-frozen, ready-to-drink, concentrated (powdered, frozen, or syrup), dairy, non-dairy, herbal, non-herbal, caffeinated, non-caffeinated, alcoholic, non-alcoholic, flavored, non-flavored, vegetable-based, fruit-based, root/tuber/corm-based, nut-based, other plant-based, cola-based, chocolate-based, meat-based, seafood-based, other animal-based, algae-based, caloric enhanced, calorie-reduced, and calorie-free products, optionally dispensed in open containers, cans, bottles or other packaging. Such beverages and beverage preparations can be in ready-to-drink, ready-to-cook, ready-to-mix, raw, or ingredient form and can use the Product as a sole sweetener or as a co-sweetener.

The Product can be used in foods and food preparations (e.g., sweeteners, soups, sauces, flavorings, spices, oils, fats, and condiments) selected from the group comprising dairy-based, cereal-based, baked, vegetable-based, fruit-based, root/tuber/corm-based, nut-based, other plant-based, egg-based, meat-based, seafood-based, other animal-based, algae-based, processed (e.g., spreads), preserved (e.g., meals-ready-to-eat rations), and synthesized (e.g., gels) products. Such foods and food preparations can be in ready-to-eat, ready-to-cook, ready-to-mix, raw, or ingredient form and can use the Product as a sole sweetener or as a co-sweetener.

The Product can be used in candies, confections, desserts, and snacks selected from the group comprising dairy-based, cereal-based, baked, vegetable-based, fruit-based, root/tuber/corm-based, nut-based, gum-based, other plant-based, egg-based, meat-based, seafood-based, other animal-based, algae-based, processed (e.g., spreads), preserved (e.g., meals-ready-to-eat rations), and synthesized (e.g., gels) products. Such candies, confections, desserts, and snacks can be in ready-to-eat, ready-to-cook, ready-to-mix, raw, or ingredient form, and can use the Product as a sole sweetener or as a co-sweetener.

The Product can be used in prescription and over-the-counter pharmaceuticals, assays, diagnostic kits, and therapies selected from the group comprising weight control, nutritional supplement, vitamins, infant diet, diabetic diet, athlete diet, geriatric diet, low carbohydrate diet, low fat diet, low protein diet, high carbohydrate diet, high fat diet, high protein diet, low calorie diet, non-caloric diet, oral hygiene products (e.g., toothpaste, mouthwash, rinses, floss, toothbrushes, other implements), personal care products (e.g., soaps, shampoos, rinses, lotions, balms, salves, ointments, paper goods, perfumes, lipstick, other cosmetics), professional dentistry products in which taste or smell is a factor (e.g., liquids, chewables, inhalables, injectables, salves, resins, rinses, pads, floss, implements), medical, veterinarian, and surgical products in which taste or smell is a factor (e.g., liquids, chewables, inhalables, injectables, salves, resins, rinses, pads, floss, implements), and pharmaceutical compounding fillers, syrups, capsules, gels, and coating products.

The Product can be used in consumer goods packaging materials and containers selected from the group comprising plastic film, thermoset and thermoplastic resin, gum, foil, paper, bottle, box, ink, paint, adhesive, and packaging coating products.

The Product can be used in goods selected from the group comprising sweeteners, co-sweeteners, coated sweetener sticks, frozen confection sticks, medicine spoons (human and veterinary uses), dental instruments, pre-sweetened disposable tableware and utensils, sachets, edible sachets, pot pourris, edible pot pourris, hotch potches, edible hotch potches, artificial flowers, edible artificial flowers, clothing, edible clothing, massage oils, and edible massage oils.

The invention will be further described with reference to the following non-limiting Examples. Unless otherwise indicated, all percentages are by weight.

The following blends of steviol glycosides are denoted using the rubric "%Wtl/%Wt2 typel/type2". For instance, "<NUM>/<NUM> RA/RB" means a sweetener in which the sweetener content by weight <NUM>% RA and <NUM>% RB by mass. The RA80 ingredient used in the experiments disclosed herein contained approximately <NUM>% total steviol glycosides. The RA50, RA80 and RA97 ingredients used in the experiments were obtained from Sweet Green Fields LLC ("SGF") of Bellingham, WA.

Aim: Determine the solubility and taste attributes of RA50/RA80/RA97 hydrolytes made using differing amounts of reaction reagent.

Hypothesis: There is a minimum RB content in a stevia extract below which the stevia extract is rendered relatively insoluble.

Hypothesis: The mere presence of significant amounts of rebaudioside B causes increased apparent solubility of high RA purity stevia extracts.

See <FIG> for solubility results and <FIG> for and sensory analysis of RA Hydrolytes.

The reaction of sodium hydroxide (NaOH) with stevia produces glucose, which causes the brown coloration of liquid concentrates made using this reaction method.

This reaction product enhances the sugar-like sensory attributes of RA/RB, i.e. mouth-feel, body, lower bitterness and improved overall liking.

Each set was tasted using double-blind Flash sensory analysis (number of analysts = <NUM>).

All samples appeared to be iso-sweet (<FIG>).

In the RA/RB samples (Set <NUM>), addition of hydrolyzed glucose at <NUM> or <NUM> ppm appeared to:.

In the RA97 samples (Set <NUM>), addition of hydrolyzed glucose at <NUM> or <NUM> ppm appeared to:.

The glucose hydrolysate appears to be acting as a flavor. At the concentration used, it likely has no functional sweetness, which was evidenced in the sweetness ratings. The sensory work was done completely blind and with sample order randomized. Even at the low concentrations used, the sample containing <NUM> ppm glucose hydrolysate was easily discernible. Even though at these low concentrations the hydrolyzed glucose acted as a flavor, the next step is to increase the concentration to determine whether at the maximum potential hydrolyzed glucose concentration (calculated at about <NUM> ppm or <NUM> % for the highest degree of hydrolysis) has negative sensory effects.

Iso-Sweet and Preference Testing for Hydrolysed Stevia (equivalent to a commercial cranberry juice having <NUM>:<NUM> RA/RB blend).

Aim <NUM>: Determine via HPLC which RA97 hydrolysis material and which RA80 hydrolysis material is closest compositionally in terms of RA to RB ratio with commercial cranberry juice having <NUM>:<NUM> RA/RB blend.

Aim <NUM>: Determine via sensory analysis what ppm level of equivalent RA97 hydrolysis material and RA <NUM> hydrolysis material is iso-sweet with commercial cranberry juice having <NUM>:<NUM> RA/RB blend in a <NUM>% sugar base.

Aim <NUM>: Determine via sensory analysis if any other treatment level of RA97/RA80 hydrolysis material are more preferred than the iso-sweet hydrolysis materials of RA97/RA80 or commercial fruit drink <NUM>:<NUM> RA/RB blend in a <NUM>% sugar base.

All samples of RA97 and RA80 hydrolysis material were compared to <NUM>:<NUM> RA100/RB blend. The samples that were closest in composition were the <NUM> reagent treated RA97 (RA97-H. <NUM>) and RA80 (RA80-H. <NUM>) samples.

HPLC chromatograms of the dry blend and RA80 and <NUM> hydrolyzed products are shown in <FIG>.

Both RA97-H. <NUM> & RA80-H. <NUM> were tested against known control <NUM>:<NUM> RA/RB blend in a <NUM>% sucrose water base samples were double blinded and tested n = <NUM> using flash sensory scales. After testing the iso-sweet was determined to be closest at <NUM> ppm, the same level found in a commercial cranberry juice.

To determine if a hydrolyzed RA product had similar taste characteristics to an <NUM>/<NUM> dry blend of RA100 and RB, <NUM> ppm concentration in <NUM>% (w/w) sugar water (cold) were compared using flash sensory to the <NUM>/<NUM> dry blend. Samples were tasted double blind and sample order was randomized. The results are shown in Table <NUM>.

Conclusions: Overall there appeared to no marked difference between samples.

Conclusions: There are no marked differences between sample taste profiles. The only relatively consistent difference was the apparent reduction in bitterness.

The samples in lines <NUM>, <NUM>, and <NUM> of <FIG> (<NUM>, <NUM>, and <NUM><NUM>% NaOH added) were prepared by mixing raw materials and then formulated in to solutions.

The results showed that for sample <NUM>-<NUM> and sample <NUM>-<NUM>, the concentrations of both glucose and salt were relative low and the difference between the samples was not significant; for sample <NUM>-<NUM> and sample <NUM>-<NUM> the concentrations of both glucose and salt were higher than sample <NUM>-<NUM> and <NUM>-<NUM>, and the difference between the samples was significant; for sample <NUM>-<NUM> and sample <NUM>-<NUM> the concentration of RB in the product was high, lowing the overall sweetness. The difference between the samples was not significant.

Hydrolysis product: Lot#<NUM>-<NUM>, comprising RA <NUM>%, RB <NUM>%, Glucose <NUM>%, and NaCl <NUM>%.

Mixed product: prepared by simply mixing raw materials according to the ratio of Lot#<NUM>-<NUM>.

The results showed that there is no difference in taste profile between the products prepared by hydrolysis and that prepared by simply mixing. The addition of glucose and salt improved the taste profile significantly, wherein glucose improved the "sugar like" profile, and salt improved the "aftertaste" profile, both the two components had positive effects on the taste profile.

Sample <NUM> was prepared according to the below hydrolysis process and the content of each component was analyzed. Another sample (Sample <NUM>), which has the same component as Sample <NUM>, was formulated by simply blending the raw materials. A control sample, which has the same RA and RB content but does not contain any salt or additional sweetener, was prepared by simply blending the raw materials. The taste profile of the three samples were evaluated.

<NUM> grams of RA97 was dissolved in deionized water and <NUM> of <NUM>% NaOH was added. The mixture was heated to <NUM> for <NUM> with stirring. The resultant mixture was then cooled, neutralized to pH <NUM> with dilute hydrochloric acid, and spray dried to affored the final product as a yellowish powder.

The product was formulated into <NUM> ppm solution with deionized water. The concentration of each component was:
<IMG>.

Sample <NUM> was prepared and formulated into <NUM> ppm solution, with RA, RB, NaCl, and glucose.

Control sample was prepared and formulated into solution with RA and RB.

Select sensory taste profiles of these three solution were evaluated, and the results were summarized below.

The results showed that there is no difference between Sample <NUM> and Sample <NUM>, demonstrating that the taste profile was determined by composition per se, regardless of the preparation process. The results showed that there is significant difference between Sample <NUM> or Sample <NUM> and control sample, demonstrating that combination of RA, RB, glucose and salts can improve the sensory profile (i.e. in this experiment sugar like, bitterness, aftertaste, and lingering) of a sweetening composition.

A composition according to the present invention was prepared from RA100 as shown in Table <NUM>.

The RA composition in Table <NUM> were prepared into solutions in Table <NUM>.

Sensory profiles were taken and are shown in Table <NUM> and Table <NUM>.

Result: The concentrations of glucose and salt in the product are low, since a relative small amount of NaOH was added. The taste profile of the product is improved in comparison with a similar composition without glucose and salt.

Result: The taste profile of the composition according to the present invention is significantly improved in comparison with a control sample without glucose and salt.

Evaluation of the effects of other sweeteners and inorganic salts on the taste profile of the composition.

Results: Substantially same results were achieved with potassium chloride and sodium chloride.

Results: The effect of fructose was slightly lower than glucose, and those of lactose, galactose, and maltose were similar or even better than glucose. The taste profiles of the compositions with an additional sweetener were significantly improved in comparison to that without an additional sweetener (sample <NUM> in test <NUM>).

The addition of carbonates to the composition may result in an "alkaline" (bitterness, astringent, and soapy) taste. Carbonates can also carbonate the composition and can result in a "soda like" taste.

Glucose may mask the "bitterness" taste of carbonates, however as shown, the aftertaste improvement can be significant.

Claim 1:
A composition comprising steviol glycosides, one or more salts, and one or more natural or synthetic sweeteners, wherein the composition comprises both rebaudioside A and rebaudioside B, and wherein:
- rebaudioside A comprises <NUM>-<NUM> wt.% of total steviol glycosides in the composition;
- rebaudioside B comprises greater than <NUM> to <NUM> wt.% of total steviol glycosides in the composition;
- rebaudioside A comprises <NUM>-<NUM> wt.% of the composition;
- the one or more salts comprise from <NUM> wt.% to <NUM> wt.% of the composition;
- the one or more natural or synthetic sweeteners comprise from <NUM> wt.% to <NUM> wt.% of the composition; and
- the one or more natural or synthetic sweeteners are selected from sucrose, fructose, maltose, lactose, xylitol, sorbitol, dextrose, glucose, mannitol, aspartame, inulin, sucralose, acesulfame-K, sodium cyclamate, erythritol, thaumatin, arabinose, galactose, mannose, rhamnose, xylose, trehalose, raffinose, cellobiose, tagatose, allulose, and mogroside.