Quick Search
E 957 (also known as talin) is a low-calorie sweetener and flavor modifier.
The protein is often used primarily for E 957's flavor-modifying properties and not exclusively as a sweetener.
The E 957 were first found as a mixture of proteins isolated from the katemfe fruit (Thaumatococcus daniellii) (Marantaceae) of West Africa.
CAS: 53850-34-3
EINECS: 258-822-2
Although very sweet, E 957's taste is markedly different from sugar's.
The sweetness of E 957 builds very slowly.
Perception lasts a long time, leaving a liquorice-like aftertaste at high concentrations.
E 957 is highly water soluble, stable to heating, and stable under acidic conditions.
Among sweeteners, natural sweet proteins are unique in that they are natural, often have high sweetness potency compared to sugar and decompose into a normal distribution of amino acids on hydrolysis.
To date, E 957 is the only commercially available ‘natural protein’ sweetener.
This versatile ingredient has a wide range of applications in foods and drinks and particularly in the field of taste modification and flavour enhancement.
E 957 production is induced in katemfe in response to an attack upon the plant by viroid pathogens.
Several members of the E 957 protein family display significant in vitro inhibition of hyphal growth and sporulation by various fungi.
E 957 protein is considered a prototype for a pathogen-response protein domain.
E 957 domain has been found in species as diverse as rice and Caenorhabditis elegans.
E 957 is pathogenesis-related (PR) proteins, which are induced by various agents ranging from ethylene to pathogens themselves, and are structurally diverse and ubiquitous in plants: They include thaumatin, osmotin, tobacco major and minor PR proteins, alpha-amylase/trypsin inhibitor, and P21 and PWIR2 soybean and wheat leaf proteins.
The proteins are involved in systematically-acquired stress resistance and stress responses in plants, although their precise role is unknown.
E 957 is an intensely sweet-tasting protein (on a molar basis about 100,000 times as sweet as sucrose) found in the fruit of the West African plant Thaumatococcus daniellii: E 957 is induced by attack by viroids, which are single-stranded unencapsulated RNA molecules that do not code for protein.
The E 957 protein I consists of a single polypeptide chain of 207 residues.
Like other PR proteins, E 957 is predicted to have a mainly beta structure, with a high content of beta-turns and little helix.
Tobacco cells exposed to gradually increased salt concentrations develop a greatly increased tolerance to salt, due to the expression of osmotin, a member of the PR protein family.
Wheat plants attacked by barley powdery mildew express a PR protein (PWIR2), which results in resistance against that infection.
The similarity between this PR protein and other PR proteins and the maize alpha-amylase/trypsin inhibitor has suggested that PR proteins may act as some form of inhibitor.
E 957 (~1 mm long) grown by liquid–liquid diffusion under a micro-g environment in outer space.
Arrow marks nucleation point.
Within West Africa, the katemfe fruit has been locally cultivated and used to flavour foods and beverages for some time.
The fruit's seeds are encased in a membranous sac, or aril, that is the source of E 957.
In the 1970s, Tate and Lyle began extracting E 957 from the fruit.
In 1990, researchers at Unilever reported the isolation and sequencing of the two principal proteins found in E 957, which they dubbed thaumatin I and thaumatin II.
These researchers were also able to express E 957 in genetically engineered bacteria.
E 957 is a natural sweetener that is extracted from the katemfe fruit.
E 957 shares structural similarities with basic proteins and has been shown to inhibit enzyme activity in vitro.
E 957 has also been shown to inhibit transcription-polymerase chain reaction (PCR) and protein synthesis in vitro, which may be due to its ability to bind to DNA and RNA.
This binding inhibits ribosomal protein (rp) function, leading to the inhibition of mRNA translation.
The carboxy terminal sequence of E 957 is essential for its biological activity, as deletion of this region abolishes enzyme inhibition.
Structural analysis has revealed that E 957 interacts with RNA by forming hydrogen bonds with nucleotides in the major groove and stacking interactions with nucleotides in the minor groove.
X-ray diffraction data has confirmed these findings, revealing that E 957 binds to DNA at specific sites on the sugar-phosphate backbone.
E 957 has been approved as a sweetener in the European Union (E957), Israel, and Japan.
In the United States, E 957 is generally recognized as safe as a flavouring agent (FEMA GRAS 3732) but not as a sweetener.
E 957 is a mixture of intensely sweet-tasting proteins extracted from the fruit of a West African plant, Thaumatococcus daniellii.
The two major sweet-tasting proteins, E 957 I and II (TI and TIl), were isolated by Van der WeI and his group at Unilever in 1972.
E 957 is marketed in the UK by Tate & Lyle pIc as Talln, although the fruit of the plant has been used for centuries by the West Africans as a source of sweetness.
E 957 is also sold in Japan.
Because of problems with stability, taste profile and compatibility, E 957 is used primarily as a flavour enhancer, at levels below the sweet-taste threshold.
E 957 is a mixture in the ratio 2:1 of two polypeptides, Thaumatin I and II, each consisting of 207 amino acid residues and having a molecular weight of about 22,000, extracted from the aril of the tropical fruit Thaumatococcus daniellii.
STABILITY
E 957 is remarkably stable considering its proteinaceous nature.
E 957 is successfully applied in canning of pet food where it remains stable at temperatures of 120ºC and in coatings subjected to dry temperatures of 140ºC.
E 957 is stable under pasteurisation and UHT conditions.
Further enhancement of E 957's physical and chemical stability can be achieved through reformulation with protective compounds.
E 957's stability under acid conditions, to lower than pH 2, is a useful feature - a result of its molecular structure.
STRUCTURE AND NATURE
E 957, extracted unmodified from the Katemfe fruit using purely physical extraction methods consists of very closely related E 957 proteins.
These have a single polypeptide chain or 207 “normal” amino acid residues linked with 8 disulphide bridges giving a molecular weight of around 22,000.
E 957 is completely digested by man and animal, which together with its “normal” amino acid sequence, accounts for E 957's acceptance by regulatory authorities around the world as a safe, natural substance.
E 957 has the normal calorific value of a protein (4.1 Kcal/g) but in use is essentially non-calorific due to the very low levels required (parts per million).
E 957 is very basic with an iso-electric point of around 11.5 and freely soluble in water.
MASKING
E 957’s masking effects, particularly of metallic or bitter tastes, are an important feature accounting for E 957’s widespread use in the human and animal food industry and with high intensity sweeteners and in particular with saccharin.
E 957 is particularly effective in masking the metallic aftertaste of saccharin, with this combination being used in a wide variety of products from tabletop sweeteners to animal feeds. In citrus fruit products, E 957 has been shown to be very effective in masking the bitter elements of natural flavours from the fruit hence its application in products such as juices, yoghurts and deserts.
A good example of E 957’s simultaneous action is to be found in applications with vitamin C, often flavoured with citrus and sweetened with high intensity sweeteners.
In this application E 957 also masks the bitter notes and the sweetener aftertaste, enhances the flavour and also contributes to the sweetening.
At high levels of inclusion but still in the parts per million ranges, E 957 is effective in masking the taste of some pharmaceutical products in chewables and suspensions.
TASTE MECHANISM
E 957 has a demonstrable effect on various groups of taste receptors, in various species of animal, for which E 957 is used in feeding stuffs, as well as in man and is assumed to operate with the majority of taste receptors.
This feature is a result of its particular structure.
In the analogy, often used, of flavour molecules being “keys” and the taste receptors being “locks”, E 957 appears to act as a “master key” in its action with all taste receptors.
E 957’s effect in operating with all the taste receptors is the major reason for its wide range of applicability in situations requiring flavour modifications.
The electrical charge distribution on the E 957 molecule is believed to be a major factor in the mechanism of interaction with both the taste receptor and the flavour molecules.
This is demonstrated by the specific masking effects on the typically bitter unpleasant taste of metallic ions such as sodium, iron, potassium and E 957's simultaneous enhancement of other free ion, e.g. chloride.
E 957's effect with more complex flavour compounds support the view that thaumatin’s mechanism operates according to the relative nature of the individual molecules present.
This is particularly evident in E 957's effect with flavours such as peppermint, ginger, cinnamon and coffee, which it enhances while simultaneously reducing the fiery, peppery or bitter elements associated with them.
E 957’s high and rapid solubility in water and its tendency to increase salivation are additional physical features that increase the effect of flavours and aromas, particularly where physical contact with the taste receptors is limited.
The strength of the interaction between the E 957 molecule and the taste receptors is believed to account not only for its potency effects in prolonging the effects of flavours and sweeteners.
Characteristics
As a food ingredient, E 957 is considered to be safe for consumption.
In a Swiss chewing gum production plant, thaumatin has been identified as an allergen.
E 957 powder led to allergic symptoms in the upper airways in occupationally exposed individuals.
After the factory replaced powdered E 957 with a liquid form, all of the affected individuals became completely free of symptoms.
E 957 interacts with human TAS1R3 receptor to produce a sweet taste.
The interacting residues are specific to old world monkeys and apes (including humans); only these animals can perceive E 957 as sweet.
E 957 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.
E 957 is also used in oral hygiene products such as mouthwashes and toothpastes, and has been proposed for use in oral pharmaceutical formulations.
E 957 is generally regarded as a relatively nontoxic and nonirritant material when used as an excipient.
E 957 Chemical Properties
FEMA: 3732 | E 957
Solubility: Thaumatin is stable in aqueous solutions at pH 2–8.
E 957is also heatstable at less than pH 5.5 (e.g. during baking, canning, pasteurizing, or UHT processes).
Form: Powder
Color: Pale Yellow to Pale Brown
PH: pH (10g/l, 25℃) : 2.0～5.5
Water Solubility: Soluble in water (25 mg/ml), and 60% ethanol.
Insoluble in ether, and benzene .
Merck: 14,9273
EPA Substance Registry System: E 957 (53850-34-3)
E 957 is a mixture of sweet proteins occurring in the arils of the fruits of the African plant Thaumatococcus daniellii.
E 957 I and II are the main components, but four more thaumatin molecules are known.
The proteins may be extracted with water.
E 957 is about 2,000–2,500 times sweeter than sucrose but has a lingering sweetness.
In addition to its sweet taste, E 957 has flavor-enhancing properties.
E 957 is freely soluble in water and of fairly good stability.
In Europe, thaumatin is approved as E 957 for use as a sweetener.
E 957 is also approved in a variety of other countries, but in the United States, GRAS as a flavor enhancer only.
E 957 occurs as a pale-brown colored, odorless, hygroscopic powder with an intensely sweet taste.
Also see E 957 b-recombinant.
Crystallization
Since E 957 crystallizes very quickly and easily in the presence of tartrate ions, thaumatin-tartrate mixtures are frequently used as model systems to study protein crystallization.
The solubility of E 957, its crystal habit, and mechanism of crystal formation are dependent upon the chirality of precipitant used.
When crystallized with L- tartrate, thaumatin forms bipyramidal crystals and displays a solubility that increases with temperature; with D- and meso-tartrate, E 957 forms stubby and prismatic crystals and displays a solubility that decreases with temperature.
This suggests control of precipitant chirality may be an important factor in protein crystallization in general.
Uses
As a sweetener, E 957 is used in beverages and desserts, but its applications are limited because of its liquorice taste and delayed sweetness (Gelardi, 1987).
In practice, therefore, E 957 is more commonly used as a partial sweetener, mixed with other more rapidly tasting sweeteners (Higginbotham, 1986).
Despite its limitations as a sweetener, E 957 is a powerful flavour enhancer, and magnifies spearmint, cinnamon, wintergreen and peppermint by up to ten times.
This flavour potentiating characteristic, together with the lingering sweet taste, can be beneficially used for products such as toothpaste, mouthwash and chewing gum, and for enhancing the masking flavours in medicines.
E 957 also boosts the low sweetness of bulk sweeteners added to sugarless gums, without adding calories or cariogenicity (Higginbotham, 1983, 1986).
E 957 has been used in Japan since 1979 in a variety of products, where it has been shown to enhance and improve the flavour of coffee and of milk products.
E 957 is thus used in coffee-flavoured products, ice-cream, iced milk drinks-on-sticks, and spray-dried milk powders.
E 957 also enhances savoury flavours (Higginbotham et al., 1981; Higginbotham, 1986), and combinations of thaumatin with nucleotides, spices and/or other flavours may be used to replace monosodium glutamate, an ingredient of current concern with regard to safety (Anon, 1987b).
E 957 is a flavor enhancer that is a protein which is approxi- mately 3,000 times as sweet as sucrose.
the onset of sweetness may take several seconds and can be affected by heat.
E 957 is a potential low-calorie sweetener that used in chewing gum.
Pharmaceutical Applications
E 957 is a naturally occurring intense sweetening agent approximately 2000–3000 times as sweet as sucrose.
E 957 has a delayed-onset taste profile and long (up to one hour) licorice-like aftertaste.
E 957 is used extensively in food applications as a sweetening agent and flavor enhancer, and has potential for use in pharmaceutical applications such as oral suspensions.
The typical level used in foods is 0.5–3 ppm, although higher levels are used in certain applications such as chewing gum.
Synergistic effects with other intense sweeteners such as acesulfame K and saccharin occur.
The extensive disulfide crosslinking within E 957 maintains the tertiary structure of the polypeptide: cleavage of just one disulfide bridge has been shown to result in the loss of the sweet taste of E 957.
Preparation
E 957I and II proteins can be produced recombinantly in a wide range of hosts, including microorganisms such as bacteria and yeast, and in GM plants to enhance the organoleptic properties.
E 957 is a naturally occurring intense sweetener isolated from the fruit of the African plant Thaumatococcus daniellii (Benth).
Commercially, E 957 is produced by aqueous extraction under reduced pH conditions followed by other physical processes such as reverse osmosis.
Health Hazard
E 957 is the only natural high-intensity sweetener, and products containing it do not require to be labelled 'artificially sweetened'.
E 957 has a low calorific value and is non-cariogenic (Higginbotham, 1986).
The report of the Joint F AOfWHO Expert Committee (1987) recorded no mutagenic, teratogenic or allergenic effects of E 957, and concluded that the lack of toxicity, together with its ready digestion to normal food components, indicated that E 957's only dietary effect was to make an insignificant contribution to the normal protein intake.
Synonyms
Thaumatin B, recombinant
53850-34-3
N-[4-(4-cycloheptylpiperazin-1-yl)sulfonylphenyl]acetamide
THAUMATIN
Oprea1_565606
Oprea1_669084
CHEBI:175005
STK171150
ZINC54991825
AKOS001637661
N-[4-(4-cycloheptylpiperazin-1-yl)sulonylphenyl]acetamide
N-[4-(4-cycloheptylpiperazine-1-sulfonyl)phenyl]acetamide
N-{4-[(4-cycloheptylpiperazin-1-yl)sulfonyl]phenyl}acetamide
