Aspartame

Aspartame is a kind of artificial sweeteners, belongs to the amino acid dipeptide derivatives, by the chemist developed ulcer drugs found in 1965. With low dosage, high sweetness (sweetness is 150 to 200 times of sucrose), good taste, enhance flavor of citrus and other fruits and reducing heat does not produce dental caries, toxicity than saccharin and other synthetic sweetening agent advantages, is widely applied to beverages, diabetic food and some slimming health food, our daily life to drink cola formula once containing the product.
Aspartame in the metabolic processes in the body and the main degradation products are phenylalanine, methanol and aspartic acid, does not enter blood circulation, and does not accumulate in the body, food for the health harmless. But due to metabolic defects in patients with phenylketonuria (PKU), excessive body phenylalanine can influence its development, so in patients with the disease to disable adding aspartame.

Neotame is aspartate dipeptide derivatives, is a new product developed at a cost of $80 million by American newt company after aspartame, representing the latest achievements of sweetener research field. It is according to the human sweet receptor double hydrophobic binding hypothesis. In aspartame molecule with a hydrophobic groups and the formation of aspartame derivatives. It can also act on the human sweet receptor of two hydrophobic binding sites and therefore sweetness increased greatly, 6000 to 10000 times sweeter than sucrose, 30 to 60 times than Biasiba sweet .
It retains many excellent characteristics such as aspartame, pure sweet taste and good flavor enhancing properties distribution, no energy, no caries, stable in acidic medium. Moreover, it is still a lot better than aspartame in dry conditions, it has a longer shelf life; in neutral medium or instantaneous high temperature sterilization conditions, its stability greatly exceed aspartame, which can be used as a sweetener in baking. Neotame can also be used together with reducing sugar and aldehyde flavor without adverse reaction, its safety is better than aspartame and has been greatly improved. Due to its high sweetness, etc. Sweeter is lower than the cost of aspartame. Therefore, neotame has huge market potential. In December of 1998, neotame as food sweeteners status of application have been proposed in the United States, and some other countries for the certification work is in July 9, 2002 . The U. S. Food and Drug Administration (FDA) confirmed the neotame safety and functional type, currently is in March 10, worldwide more regulatory agency and national review in 2003, China's Ministry of Health approval for neotame as a sweetener used in all kinds of food.
The above information is edited by the Chemicalbook Han Ya.

Accurately take sample of about 300 mg, moves into a 150ml beaker, dissolve in 96% formic acid 1.5ml, and glacial acetic 60ml. with crystal violet solution (ts-74), with 0.1 mol/L HClO4 immediately titrate to the end of green. At the same time a blank titration and make necessary correction. Each mI.0.1mol/L perchloric acid is the equivalent of 29.43mg C14H18N2O5.

Entering the human body can quickly metabolic day aspartic acid and phenylalanine, two kinds of amino acids are absorbed, which does not accumulate in the organization. But phenylketonuria patients cannot use. Therefore it is necessary to specially marked. Every year in China about 1500~2000 benzene acetone urine disease in children born, after eating can be in vivo abnormal accumulation caused by brain damage, mental development retardation and epilepsy.
The ADI value is 0~40mg/kg (FAO/WHO, 2001). Contains two ketone piperazine ADI value is 0~7.5.
GRAS (FDA, 172.804,2000).

GB 2760-2001: all types of food (except canned food), are limited to GMP.
FAO/WHO (1984): sweets 0.3%, gum 1.0%; beverage 0.1%, 0.5% of breakfast cereals, and used for the preparation of diabetes, hypertension, obesity, cardiovascular patients with low sugar, low calorie health food, dosage depends on the need to set. Can also be used as flavor enhancer.

White crystalline powder, odorless, there is strong sweet, sweet and pure, sweetness of sucrose was 100-200 times. Melting point is 235℃ (decomposition). Amino acids is with the general nature. In dry conditions or pH value of 2 to 5 range, it is stability, strong acidic water solution can hydrolyzed to produce amino acid monomer, in neutral or alkaline conditions it can be cyclized to diketopiperazine. Solubility in water (25℃) is relevant to pH value, pH 7.0 was 10.2%, pH value 3.72 is 18.2%. At 25, isoelectric point is pH value of 5.2. Mice by oral LD50 > 10 g/kg Adl is 0~40mg/kg (FAO/who, 1994)

1.Asparagus sweet is artificial synthesis of low calorie sweeteners, often used with sugar or other sweeteners. It can be used for all kinds of food, according to the production need to use, the general dosage is 0.5g/kg.
2.It Is used as a food additive, high sweetness nutritive sweeteners.
3.Non nutritive sweeteners. Flavoring agents.
4.According to China GB2760-90 provisions for all kinds of food, the maximum amount of use as normal production needs. According to the FAO/WHO (1984) provisions for sweets, dosage of 0.3%, 1.0% gum, beverage 0.1%, 0.5% of breakfast cereals, and used for the preparation of diabetes, hypertension, obesity, cardiovascular patients with low sugar, low calorie health food, dosage depends on the need to set. Can also be used as a flavor enhancer.
Aspartame is a L-aspartic acid and L-phenylalanine (body needed nutrients) two peptide synthesis, can be completely absorbed by the human body metabolism, non-toxic harmless, safe and reliable, cool and refreshing taste like sugar, but is 200 times sweeter than sucrose, the heat is only 1/200 sucrose, eat no gingivae that does not affect the blood glucose, obesity, hypertension, coronary heart disease. The World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO) identified as A (1) level of sweetener, has been in the world more than 130 countries and regions approved for use. Widely added in a variety of food, non-staple food and all kinds of hard and soft drinks, the use of aspartame has more than 4000 kinds of varieties. Can be used as food additives, high sweetness sweeteners with nutrition. Packing: 25 kg fibreboard drum, lined with plastic bag.

1. By L-aspartate and L-phenylalanine methyl ester condensation.
2. By L-aspartic acid and L-phenylalanine methyl ester hydrochloride condensation.
There are two kinds of synthetic and enzymatic synthesis.
enzymic synthesis ：
Department of chemistry, Wuhan University, Tao Guoliang, gave the following synthetic route:
The preparation of I : 0.5mmol benzyloxy carbonyl aspartic acid, 1.5mmol phenylalanine methyl ester hydrochloride and 2.5ml water were added to 25 ml Erlenmeyer flask, with ammonia to adjust the pH to 6, adding 7mg of thermophilic protease, at 40℃mixing reaction for 6h. Filter and washed with distilled water, and drying to obtain white solid (I) 0.29g, 95.6% yield, melting point is 116 to 118 ℃. Elemental analysis results: C 62.96%, H6.09%.N of 6.65%.
preparation of II: it will be joined the conical flasks 0.5g sample I and 20mL3mol/L hydrochloride 25ml and 45℃ in the mixing reaction for 0.5h. Filtration and washing with distilled water, drying to obtain 0.32g the product II, yield is 92%, melting point is 129 to 131℃. Elemental analysis results: C 61.45%, H 5.42% , N 6.82%.
Preparation of III will 0.2g palladium carbon catalyst (10%), 20 ml of glacial acetic acid, 5 ml of water add 100 ml three necked flask, hydrogenation activation 1.5h. Join 0.6g II 20 ml acetic acid dissolution and, at 30℃ stirring hydrogenated after 6h. the reaction is completed after filtration, catalyst with acetic acid washing 3 times; the filtrate and washings were concentrated under reduced pressure to dry, 15ml of benzene, continue to decompress and concentrate to dry white solid, and drying to obtain 0.38g the product III, and the yield was 92.3%, the melting point is 245 ℃. The elemental analysis results: C 55.63%, H6.23%, N 8.96%.
Chemical synthesis method
The aspartic acid and phenylalanine as raw material, by amino protection, anhydride, condensation, hydrolysis, neutralization and other steps of the synthesis. Different protecting groups, different methylated sequence can have a variety of different synthesis methods. Such as the use of formyl as protecting groups and after methyl esterification process route.Into a 250ml flask into 27mL 95% of the methanol and 0.2g oxidation of magnesium and magnesium oxide is dissolved, add 100ml 98% of acetic anhydride, at this time, the temperature gradually rose to 40 ℃, adding acid 67gL-aspartic, heated to 50℃, stirring reaction time 2.5h insulation and fill with 15mL98% acetic anhydride, temperature and reaction time 2.5h, join 16ml isopropanol and continue for 1.5h, the reaction after cooling to room temperature.
Put the inner anhydride materialized to join 1000ml flask, add 207mL ethyl acetate and 66Gl-phenylalanine, stirring 1.5h in 25 to 30℃, add the glacial acetic acid 126mL, continue to reflect 4.5h, the reaction after the end of the vacuum to remove the solvent and to the temperature of the reaction system 65℃ so far. Then add 35% hydrochloric acid methylmercury, heating to 60 ℃, return at the end of the reaction of the hydrolysis of 2h, atmospheric distillation until boiling temperature of 63℃ (reaction temperature of 73 degrees C) so far, adding methanol 180, to continue the distillation to the system temperature of 85 ℃ so far. After cooled to 25℃, the removal of the vacuum light group.
Adding 35% hydrochloric acid 54mL to the hydrolysis liquid, methanol 9mL and water 43mL. In 20 to 30℃for esterification reaction was then filtered, washed separation from α-APM hydrochloride. It dissolves in 600ml distilled water, to 40 to 50 ℃ of 5%~10% NaOH solution and to Ph=4.5. cooling below, filtering, washing to α-APM crude product, and then dissolved in 500 ml of methanol and water (volume ratio of 1:2) mixture. The cooling crystallization, filtration washing, vacuum drying 45% yield in terms of L-phenylalanine.
The Japanese scholars put forward a route without protection:
90g phenylalanine methyl ester hydrochloride is dissolved in 450mL water, 24g sodium carbonate neutralization, two vinyl chloride extraction and 2350mL obtained. Adding 9g phenylalanine methyl ester of acetic acid and methanol extracts 8mL, 15.2g aspartic anhydride hydrochloride added at-20 deg.c, stirring for 30min, hot water and sodium carbonate were added to 70~80 350mL C (5.7g) 300mL. solution with 150mL two vinyl chloride 2 remaining after extraction of phenylalanine methyl ester, water with dilute hydrochloric acid to adjust the Ph value to the 4.8. of the aqueous solution of paper electrophoresis measured with 18.2G (molar yield of 60%) and 6.1g (α-APM beta 20% molar yield) β--APM. This solution is vacuum concentration 100mL, plus.36% hydrochloric acid 30mL, set the refrigerator overnight. A-APM-HCl 21.3g Precipitation Crystallization (yield 58%), the crystallization of filtered and dissolved in 200mL water solution. Stirring at 50 ℃, with 5% sodium carbonate solution to adjust the Ph value to 4.8, and then place the refrigerator overnight in the analysis And filtering to obtain alpha APM crystallization) (43% yield). Crystal dissolved in 500ml water. In 45℃ by Dowex 1 x 4 (acetate) columns (1 x 20cm), and 20 ml of water flushing, effluent and washings together vacuum concentration, precipitation of alpha APM crystallization 11.2g. yield of 37%, melting point 235~236℃ (decomposition), than the rotation alpha D22 32.0 ℃ = 1, Cu Suanzhong. Elemental analysis results: 55.30% C, H 6.19%, n 9.36%.

Toxic substances

Edible contact dermatitis.

Combustible; combustion produces toxic nitrogen oxide smoke

Combustible; combustion produces toxic nitrogen oxide smoke

Dry powder, foam, sand, carbon dioxide, mist water

Aspartame is a synthetic non-caloric sweetener that is metabolized to phenylalanine, aspartic acid, and methanol in the gut. Aspartame (80 mg/kg per day for 90 days) increases plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, induces hepatocyte degeneration and leukocyte infiltration in the liver, and reduces hepatic levels of reduced glutathione (GSH), oxidized glutathione (GSSG), and γ-glutamylcysteine (γ-GC) in mice. Formulations containing aspartame have been used as sweetening agents and flavor enhancers in foods and beverages.

Aspartame is the most popular artificial sweetener in the United States. It is sold as sweeteners such as NutraSweet and Equal, but it is also incorporated into thousands of food products.

Aspartame has no odor, but has an intense sweet taste. It is a high intensity sweetener, about 160 to 200 times sweeter than sucrose. Normal digestive processes convert aspartame to phenylalanine, aspartic acid and methanol. Metabolism of aspartame in the body provides approximately 17 kJ (4 kcal)/g. The stability of aspartame is affected by moisture, pH and temperature. For a detailed description of this compound, refer to Burdock (1997).

white powder or tablets

Aspartame occurs as an off white, almost odorless crystalline powder with an intensely sweet taste.

Aspartame (N-L-aspartyl-L-phenylalanine-1-methyl ester, 3-amino-N-(a-carbomethoxy- phenethyl)-succinamic acid-N-methyl ester) is an intense sweetener widely used in foods and beverages. Its solubility in water is approximately 10 g/L at room temperature. Aspartame is not fully stable under common processing and storage conditions of foods and beverages with the highest stability around pH 4.3. Aspartame is about 200 times sweeter than sucrose with a clean, but slightly lingering sweetness. It is used as the single sweetener, but often also in blends with other intense sweeteners owing to synergistic taste enhancement and taste quality improvement often seen in such blends.
In the European Union, aspartame is approved as E 951 for a large number of food applications. In the United States, it is approved as a multipurpose sweetener for food and beverage uses and it is also approved in many other countries.

Canderel,Searle,France,1979

Aspartame was discovered accidentally in 1965 during a search for drugs to treat gastric ulcers. James M. Schlatter, an organic chemist working for G. D. Searle & Company, was using aspartyl-phenylalanine methyl ester (aspartame) in a synthesis procedure and inadvertently got some of the compound on his hands.

Aspartame in powder form for limited uses such as cereals, powdered drinks, and chewing gum. When aspartame is used in baked goods and baking mixes, it should not exceed 0.5% by weight. Packages of the dry, free-fl owing aspartame are required to prominently display the sweetening equivalence in teaspoons of sugar.

A dipeptide ester about 160 times sweeter than sucrose in aqueous solution. A non-nutritive sweetener.

The chemical name for aspartame is L-aspartyl-L-phenylalamine methyl ester.
It is a white crystalline powder and is about 200 times as sweet as sucrose. It is noted for a clean, sweet taste that is similar to that of sucrose.
Aspartame is the most widely used artificial sweetener in the world. It was approved by the FDA for use in the USA in 1981, and now is approved for use in several other countries of the world. One of the drawbacks of aspartame is its instability to heat and acid. Under acidic conditions aspartame slowly hydrolyzes leading to a loss of sweetness, chemical interaction, and microbial degradation. The shelf life of the aspartame-sweetened products with high water content is limited to about 6 months, after which it breaks down into its constituent components and loses its sweetening abilities. At elevated temperatures, solid aspartame slowly releases methanol to form aspartyl phenylalamine and the dioxopiperazine. This reaction is especially favored at neutral and alkaline pH values. Because of this reason, aspartame cannot be used in hot baking foods.
Another disadvantage of aspartame was noticed in the human digestive system. When the body ingests aspartame, it breaks down into its three constituent components: phenylalamine, aspartate, and methanol. The phenylalamine and aspartate are handled by enzymes in the stomach and in the small intestine, while the methanol is transported to the liver for detoxification. The metabolism of phenylalamine requires an enzyme that is not produced by a small proportion of the population having a genetic disorder called phenyl keton uria (PKU). Aspartame should be avoided by persons suffering from PKU. A warning to PKU sufferers on aspartame-containing products is required in many countries.

Aspartame is a high-intensity sweetener that is a dipeptide, provid- ing 4 cal/g. it is synthesized by combining the methyl ester of phenylalanine with aspartic acid, forming the compound n-l-alpha- aspartyl-l-phenylalanine-1-methyl ester. it is approximately 200 times as sweet as sucrose and tastes similar to sugar. it is compara- tively sweeter at low usage levels and at room temperature. its mini- mum solubility is at ph 5.2, its isoelectric point. its maximum solubility is at ph 2.2. it has a solubility of 1% in water at 25°c. the solubility increases with temperature. aspartame has a certain insta- bility in liquid systems which results in a decrease in sweetness. it decomposes to aspartylphenylalanine or to diketropiperazine (dkp) and neither of these forms is sweet. the stability of aspartame is a function of time, temperature, ph, and water activity. maximum stability is at approximately ph 4.3. it is not usually used in baked goods because it breaks down at the high baking temperatures. it contains phenylalanine, which restricts its use for those afflicted with phenylketonuria, the inability to metabolize phenylalanine. uses include cold breakfast cereals, desserts, topping mixes, chew- ing gum, beverages, and frozen desserts. the usage level ranges from 0.01 to 0.02%.

Non-nutritive sweetener.

ChEBI: A dipeptide composed of methyl L-phenylalaninate and L-aspartic acid joined by a peptide linkage.

Aspartame is produced by coupling together L-phenylalanine (or Lphenylalanine methyl ester) and L-aspartic acid, either chemically or enzymatically. The former procedure yields both the sweet aaspartame and nonsweet β-aspartame from which the α-aspartame has to be separated and purified. The enzymatic process yields only α-aspartame.

Aspartame is synthesized using the L enantiomer of phenylalanine. The L enantiomer is separated from the D enantiomer, the racemic mixture, by reacting it with acetic anhydride (CH₃₂