Sweeteners thaumatin

Thaumatin is a group of intensely sweet basic proteins isolated from the fruit of Thaumatococcus danielli (West African Katemfe fruit). It consists essentially of the proteins Thaumatin I and Thaumatin II. Thaumatin is a taste-modifying protein that functions as natural sweetener or flavor enhancer. Thaumatin is stable in aqueous solutions between pH 2.0 and 10 at room temperature. As occurs with aspartame it is nutritive, containing 4kcalg , but due to its intense sweetness, the amounts used are small enough for thaumatin to be considered and classified as a nonnutritive sweetener. Thaumatin is approved for a number of uses in UK, Japan, Australia, the EU, and in many other countries. In the USA, it is approved as a flavor enhancer. 

Thaumatin (trade name Talin) is a very potent sweetener (ca 2000X, 10% sucrose solution sweetness equivalence). However, its potency is overshadowed by inferior taste quaUties. The onset of sweetness is very slow, and after reaching the maximum sweetness, a very long-lingering sweetness combined with an unpleasant aftertaste follows. Primarily owing to this poor taste quaUty, thaumatin is not considered a practically useflil sweetener. It is, however, used as a flavor enhancer, especially in products such as chewing gum. Thaumatin and thaumatin B-recombinant were affirmed GRAS flavors (EEMA no. 3732 and 3814, respectively). They are not approved as sweeteners in the United States. 

As a protein, thaumatin is remarkably water-soluble (up to 60%) and is stable to heat at low pH. It has been reported that a thaumatin solution at pH less than 5.5 can be heated at 100°C for several hours without loss of sweetness. Comprehensive reviews on thaumatin as sweetener are available (100,101). 

Sweeteners can be roughly divided into two groups bulk and intense sweeteners. Prodolliet (1996) and Gloria (2000) reviewed thoroughly the analysis and properties of intense sweeteners acesulfame-K, alitame, cyclamate, aspartame, glycyrrhizin, neohesperidin DC, saccharin, stevioside, sucralose and thaumatin. They are generally used in low calorie products such as diet... 

Other than the sweeteners discussed so far thaumatin is a polypeptide consisting of amino acids commonly found in food proteins. It is quickly and completely digested like proteins and did, after demonstration of its metabolic characteristics, only require a rather limited set of safety data. In contrast to the other intense sweeteners the ADI of thaumatin is not specified , as for substances of similar composition.27 It is approved in many countries but, owing to its flavour enhancing properties, is often used as a flavour enhancer rather than a sweetener. 

Intense and bulk sweeteners are endorsed by international agencies and approved in a large number of countries. Acesulfame K, aspartame and saccharin are available as sweeteners in the EU and Europe while sucralose is approved in the USA and due for approval in Europe and cyclamate, neohesperidin dihydrochalcone and thaumatin are available in Europe. As bulk sweeteners isomalt, lactitol, maltitol, mannitol, sorbitol and xylitol are commonly available. 

The design of safe sweeteners is very important for people who are afiected by diabetes, hyperlipemia, caries and other diseases that are linked to sugar consumption. Sweet proteins, which are found in several tropical plants, are many times (100-100,000) sweeter than sucrose on a molar basis. Only a few sweet proteins are known miraculin, monellin, thaumatin, curculin, mabinlin. 

Thaumatin has been approved as a sweetener in the European Union (E957), Israel, and Japan. In the USA, it is a Generally Recognized as Safe flavoring agent. (FEMA GRAS 3732). 

Sweet Taste. The mechanism of sweetness perception has been extensively studied because of its commercial importance. Many substances that vary in chemical structure have been discovered which are similar to the taste of sucrose. Commercial sweeteners include sucralose, acesulfame-K, saccharin, aspartame, cyclamate (Canada) and the protein thaumatin 4), Each sweetener is unique in its perceived sensation because of the time to the onset of sweetness and to maximum sweetness, ability to mask other sensations, persistence, aftertaste and intensity relative to sucrose [TABLE IT. For example, the saccharides, sorbitol and... 

In some cases, yeast preparations which contain a high amount of nucleotides can be used to increase saltiness in combination with masking ofiF-notes of KCl [30]. Additionally, use of low amounts of fruit acids may reduce the bad taste of KCl-containing food preparations [31]. Usage of low amounts of sweeteners such as thaumatin [32] or neotame [33] was described to mask the ofiF-taste of KCl. 

Thaumatin is 1600-3000 times sweeter than sucrose. However, it has unusual taste profile slow in onset, followed by intensification to lingering sweetness, with a licorice-type aftertaste (Table 1). To achieve a taste closer to that of sucrose, thaumatin must be blended with other intense sweeteners or with sugars. By combining thaumatin with alanine and organic acids, there is a doubling in sweetness and a reduction in the aftertaste and in the delay in sweetness. Thaumatin has the ability to enhance certain flavors and aromas, such as those in peppermint, spearmint, coffee, and ginger (8,57,58,123,125). 

Formulators in most markets now have a wide range of sweeteners available to use either alone or in combination. As Figures 4.1 and 4.2 show, the main intense sweeteners in use in soft drinks today are acesulfame K, aspartame, saccharin and cyclamate. Currently of less importance commercially (either because they are new to the market or because they have not found significant use in soft drinks), but still approved for use in soft drinks in some markets, are thaumatin, neohesperidin diliy-diochalcones, alitame, stevioside, sucralose and neotame. 

This protein sweetener is extracted from the berry of a fruit which grows in west Africa. It has been sold under the trade name Talin. Thaumatin is intensely sweet. The sweetness is slow in onset but is long lasting with a liquorice end-note. It is little used in confectionery although it has been used as a coating on the outside of chewing gum where its persistence would be an advantage. 

Interestingly, the human TAS1R2/TAS1R3, but not its mouse counterpart, are sensitive to the sweet proteins monellin, thaumatin, and brazzein, and to the artificial sweeteners neo-tame, cyclamate, and aspartame (9-11). This difference provides a molecular explanation for the previous observation that these compounds are sweet for humans but not attractive to rodents (9). The species difference also applies to the inhibitor lactisole that blocks the sweet taste in humans but not in rats, and only inhibits the response of human TAS1R2/TAS1R3 to sweet stimuli (9). 

Several plant-derived proteins have been reported previously as sweeteners, inclusive of curculin [103], mabinlin [104,105], monellin [28,106], pentadin [107], and thaumatin, with the latter compound already mentioned as having commercial use as a sweetener and flavor enhancer [22]. Recently, a sixth sweet protein of plant origin, brazzein, was isolated from the fruits of an African climbing vine, Pentadiplandra... 

Thaumatin is a naturally occurring intense sweetener isolated from the fruit of the African plant Thaumatococcus daniellii (Benth). Commercially, thaumatin is produced by aqueous extraction under reduced pH conditions followed by other physical processes such as reverse osmosis. 

Thaumatin is accepted for use in food products either as a sweetener or as a flavor modifier in a number of areas including Europe and Australia. It is also used in oral hygiene products such as mouthwashes and toothpastes and has been proposed for use in oral pharmaceutical formulations. Thaumatin is generally regarded as a relatively nontoxic and nonirritant material when used as an excipient. In Europe, because of its lack of toxicity, an ADI has been set of not specified . ... 

Hart H. Thaumatin. In Birch G, ed. Ingredients Handbook Sweeteners, 2nd edn. Leatherhead Leatherhead Publishing, 2000 255-263. 

Higginbotham JD. Talin protein (thaumatin). In O Brien Nabors L, Gelardi RC, eds. Alternative Sweeteners. New York Marcel Dekker, 1986 103-134. 

Thaumatin Plants Sweetener Production Process by Fermentation of Yeast Available. 

Do these diverse compounds give rise to a common perception of sweetness or to qualitatively different sensations Sweetness does indeed appear to be a unitary percept (Breslin et al. 1994,1996). However, some sweeteners may be discriminable on the basis of their activation of other sensory transduction mechanisms or differences in the temporal properties of their sensory action. For example, the sweetener sodium saccharin activates bitter receptors in some people (Kuhn et al. 2004 Pronin et al. 2007), and also inhibits sweet taste at high concentrations (Galindo-Cuspinera et al. 2006). Sweet proteins such as thaumatin and monellin can have a slow onset or evoke a prolonged sweetness compared with sugars (Faus 2000), likely owing to a relatively high affinity for the sweet taste receptor. 

Sweeteners have been applied to foodstuffs for many years. Compounds such as saccharin, sodium cyclamate, aspartame, and several others are well known and hardly need to be discussed here. In later times, sweeteners such as sucralose and thaumatin appeared on the scene. Sucralose is a sucrose derivative obtained by chlorination, by which the D-glucopyranosyl unit is converted to a galactopyranosyl unit chlorinated at position 4, while the fructofuranosyl unit is chlorinated at positions 1 and 6. This results in an intense sweetness (600 times that of sucrose) and a greater stability toward acids (Figure 12.2). 

---