M odern day sweeteners are intended to fulfil a number of parallel tasks. To bring about a sweet taste is the most important but rarely the only aspect. Because the preparations should optimally support, reinforce and distribute the taste in general. The collected sensation of taste is experienced as drained when the sweet sensation is over. This goes above all for chewing gum.

A chewing gum usually demands that the effect of the sweetener lasts for 15- 20 minutes.

T o visualize the nature of a sweetener one usually plots its experienced sweetness in relation to time and possibly temperature.

F ructose has a relative sweetness of about 1,5 compared to sugar. The taste is quickly noticeable, but fades out in a moment, as well. Sugar has a more planer, flatter curve of intensity than fructose has over time. Grain syrup has a flatter curve of intensity than both of fructose and sugar. Grain syrup has with a dextrose equivalent of 42 a relative sweetness of 0.5.

T he secret behind a long taste often stems from a high molecule weight. Large molecules are inclined to place themselves as a covering layer in the mouth cavity, masking the initial impact of other tastes, as well. This gives a good sensation of taste over time for the whole complex. It´s possible to reduce certain aftertastes stemming from highly intensive sweeteners through this procedure, as well. Another common way of distributing taste over time in the context of sweets is encapsulation into small units.

P reviously sweetening agents were used nearly extensively as sugar replacement in dietistic purpose. They are much more used as a complement to caloric sugar to bring about a precise taste sensation these days.

S weeteners such as dextrose, with a negative heat of solution, is experienced as cooling in sweets. This is frequently utilized. Polyoles have a cooling effect and works taste distributing over time where they have a high molecular weight. Xylitol and sorbitol are the most cooling. Their sweetness is 1.0 and 0.62 respectively compared to sugar. Contributions from, for example, 1-mentol may be included in the collected perception of coolness. The effect mechanism is different here, as the proper nerve ends are immediately stimulated by the chemical substance. However, 1-mentol is experienced as burning in high concentrations.

A new sweetener, Tagose, is extracted from whey. Tagose is patented by the company Spherix and the manufacturing rights are held by Arla Foods. The deal between Arla and Spherix maintains that Spherix is to be compensated with royalties for sold volumes. Many large companies, such as Herhey´s Wrigley, PepsiCo, Kraft and Kellog stands in line to use Tagose in their production.

F ollowing the discovery of aspartame, a systematic searching for similar compounds with improved qualities was carried out during the seventies. Alitame was synthesized by researchers at Pfifer Central Research in 1979. Alitame is a odourless and non hydroscopic, chrystallized substance with a high solubility in water. Its isoelectric point lies at p.H 5.6. It is a highly potent sweetener, 2000 times sweeter than sugar and extracted through the concept for receptor – ligant – optimation in medicine research. A grenade of sulphurous amide has been attached to a dipeptide, consisting of L-asparagin acid and D-alanine, at the acid terminal of the alanine.

T he branched, bulky structure has proved to be important in order to fit into the receptor in an optimal way. Structures up to 3900 times stronger than sugar, but worse than alitame in a united context were found here. Alitame yields very moderate touches of aftertastes and shows an impressive stability in comparation to aspartame, especially above the higher p.H intervals. Its proof to warmth is much better than that of aspartame, as well. The body breaks down alitame into the components of asparagines acid and alaninamide, both of these substances into harmless amounts.

S accharin is the oldest of the presently used artificial substances for sugar replacement, originally produced in 1879 by Mr. Constantine Fahlberg. It is a petroleum based preparation 500 times sweeter than cane sugar in its pure condition. Easily dissolved in important solvents such as glycerole and propylenglycole. Its sweet flavour appears with a certain delay, followed by a bitter aftertaste. Saccharin presents little interactivity with bodily substances, hence it is not metabolized after eating. One can be certain that it´s food value and caloric content is nonexistent because of the very same reason. That is why saccharin is used in dietistic purposes, except in case of malignant caries, as well.

S odium can be found as a counter-ion in sodium saccharin which can be worth of consideration as an exception. Saccharin can trigger allergic reactions of the more serious kind as an exception. Repeatedly attempts to prove that saccharin may increase the risk of cancer in the bladder of experimental animals have been made. Some of these attempts have been strongly criticized, among other things because of the excessive amounts of preparations directly injected. Still, no proper results translated into risks for men has emerged. There are yet places where attempts is made to prohibit or restrict sale of the substance, but this is because of its allergenic qualities.

S accharin is produced by allowing C12SO2OH to react with toluene, as two products, one with SO2C1 in the ortho site, and one with SO2C1 in the para site, are produced. When the ammonium carbonate is added, the most of the reagent will react to the next product over the ortho shape, through the balance between the ortho- and the para site and accordingly to the principle of Le Chatelier, as NH2 has replaced C1. The resulting substance is brought together with highly concentrated KMnO4, and must react at 150 degrees centigrade. The methyl group in the original toluene is then transformed into –COOH and the molecule reacts internally in an acid base reaction during production of water. Saccharin is made.

T he sweetener cyclamate was produced in 1937, hence it is a rather old preparation, as well. Cyclamate is 40 times sweeter than cane sugar. Cyclamate is said to work synergic with other sweeteners and may frequently result in a decrease of aftertaste. Cyclamate has been used together with saccharin above all. Cyclamate is not metabolized in most people, among the people where it is and to what extent it is metabolized, cyclohexylamine mainly constitutes the metabolite. Cyclohexylamine has been tested in a large number of tests along side cyclamate. No substancial evidence of increased risk of cancer with usage in human beings has been presented. As with saccharin the main suspicion have been pointed out towards possible cancer in the bladder. Cyclamate has achieved a wide application as a consequence of its harmlessness, its stability in heat, among other things, and its good qualities in the context of combined sweetening.

T he precursor of cyclamate, cyclohexylamine, is produced by catalytic hydration of alinine during high temperature and high pressure or through reductive ammonification in a reaction between cyclohexanone and ammonia. The cyclohexylamine is sulphatized into cyclamate after that.

A spartame was dicovered in 1965 by Jim Schlatter, a chemist at G.D Searle and became a very popular sweetener in a couple of decades. The strength of the flavour depends on concentrational conditions, but is usually considered about 180 times stronger than sugar. Aspartame lacks most of the bitter aftertaste that often appears with other strong sweeteners. Its sweet touch is somewhat more delayed than in the case of sugar, and the taste remains longer, as well. The stability is optimal at pH 4.3 and the iso-electric point is found at p.H 5.7. Aspartame is disintegrated into asparagic acid, fenylalanine and methanol in the body. The amount of methanol formed is well below the limit of what the liver can handle and the caloric content stops at 4 calories per each gram, which is negligible in relation to the amounts of aspartame used. Usual sugar yields 9 calories per each gram in decomposition.

T wo of the building block of aspartame is chiral which is why the molecule will have two stereogenic centers in its entirety, which must be of the proper kind in order to allow the molecule to tie into the taste receptor as a ligant. The synthese of aspartame stems from a racemical mixture between aspartic acid and phenylalanine. The mixture must react with acetic anhydride and sodium hydroxide. The product is treated with an enzyme, an acylase, and extraction with an organic phase takes place during acidization. The L-enantiomer of pnenylalanine will now be found in the water phase and the D-enantiomer in the organic phase. L-phenylalanine is esterified through treatment with a combination of methanol and HCI, whereupon the ester reacts into aspartame with aspartic acid.

T he amino group and the acid group must be protected with a carboxylic group and a bensylic group, respectively, in the final phase. The reagent of Castro activates the proper acid group, but must not be allowed to participate by itself in the reaction with phenylalanine after the activation. Eventually the protectional groups must be removed.

M an has the ability to differ between 5 different kinds of tasts, namely: sour, salt, bitter, sweet and umami. Every taste bud consists of 50- 100 cells. (There are three kinds of taste buds, counted from shape and location : fungiform, foliate and circumvallate)

G proteins, and to these connecting receptors, ”G protein coupled receptors” (GPCRs), are usually mentioned in the context of sweet flavour. GPCRs is the blanket term for a very large group of (more than 1300 kinds) receptors of a common sort, and they are sometimes referred to as 7 transmembrane receptors, since their primary structure shows 7 sections which are intended to cross membranes. The flavours whose detectional mechanisms is supported with GCPRs are sweet, bitter and umami. There are three different GCPRs concering the flavours of sweet and umami, T1R1, T1R2 and T1R3, namely.

T he flavour of umami is probably detected through that T1R1 and T1R3 are connected across the proper ligants. Sweet flavour is detected through that T1R2 and T1R3 are connected across the sweet ligants. T1R1 mostly appears in fungiform and foliate tastebuds whereas T1R2 mainly exists in circumvallate and foliate tastebuds. T1R3 either appears with T1R1 or with T1R2. The T1R2 and T1R3 of human beings seems interestingly enough to be much more sensitive to artificial sweeners than in the case of rodents.

A s the sweet component ties into T1R1 and T1R2, a change of conformation takes place in these units whereupon the connecting G protein of GPCR brings about an activation of an enzyme, adenylcyclase. The enzyme supports the production of 3. 5- cyclic AMP from AP. The presence of 3, 5- cyclic AMP (cAMP) makes a protein kinase activate proteins in the (K+) channels which are closed in this way. Ca2+ is picked up into the cell, instead of K+, which responds by releasing a neuro transmitter substance, which is detected by the signal promoting synapses of certain nerve cells.

   Kåre andersson