Molecular formula: c14h18no5.
Description: White powder, odorless, with strong sweetness.
Aspartame, commonly known as sweetener, is condensed from L- aspartic acid and L- phenylalanine methyl ester hydrochloride. The chemical name is methyl aspartate, and its sweetness is 180 times that of sucrose. Sweetness is very similar to sugar, with a cool feeling, no bitterness and no metallic taste. The PH value of 0.8% aqueous solution is 4.5-6. Long-term heating or high temperature will cause damage. Unstable in aqueous solution, easy to decompose and lose sweetness, stable at low temperature and PH 3~5. It is ideal to prepare it or use it in frozen food when it is used.
Sweetness was found in 1965. Developed and patented by Seark Company of the United States, it was approved as a food additive by the US Food and Drug Administration (FDA) on 1974. Sweeteners are widely used because of their non-toxic, low-calorie, high-sweetness, non-obesity, no dental caries and no cardiovascular diseases, and have been listed in the 22nd edition of the United States Pharmacopoeia and the United States Pharmacopoeia of Food Chemistry (1983). Its synthetic route is simple and clear.
preparation method
Take 13.38 (0. 1 mol/L) aspartic acid, add appropriate amount of magnesium oxide, formic acid and acetic anhydride, dissolve and stir for 5 hours, then add isopropanol, continue stirring 1 hour, and then add ethyl acetate, glacial acetic acid and14.9 g (0.09 mol). Adding a proper amount of dilute hydrochloric acid to I for hydrolysis, reacting at 60℃ for 4.5, neutralizing with dilute sodium hydroxide, filtering and washing with water to obtain II16.2g with a yield of 35.5%. Appropriate amount of dilute hydrochloric acid, methanol and magnesium chloride hexahydrate were added to II, stirred at room temperature for 72 hours, filtered and washed with 1n hydrochloric acid to obtain III13.4g with a yield of 79.2%. Dissolve III in appropriate amount of water, adjust pH to 4.5 with ammonia water, filter, wash with water and dry to obtain IV (sweetener) 1 1.9g ... recrystallize IV with 50% methanol to obtain white needle-like crystals 1 1.7g, with an overall yield of 44.2% (. The structure and quality of the sweetener were confirmed by TLC and HPLC, and the quality met the standard of the 22nd edition of the United States Pharmacopoeia. "
Toxicity can be rapidly metabolized into aspartic acid and phenylalanine after entering the human body and being absorbed, and will not accumulate in tissues. However, patients with phenylketonuria cannot use it and need special labeling. About 1500 ~ 2000 cases of children with phenylketonuria are born every year in China, which can accumulate abnormally in the body after eating, causing brain damage, mental retardation and epilepsy.