Glutamate salt

A review of the mechanism of thermal 2 + 2-cycloadditions of activated alkenes to allenes and ketenes has been published. " Stereoselective intramolecular 2 + 2-cycloadditions of alkene-keteniminium salts (19) derived from L-glutamic salts yield... 

An interesting recent development is the use of arginine-glutamate salt (typically 50 mmol l-1 L-arginine + 50 mmol l-1 L-glutamate) for NMR studies of proteins using CC probes. This zwitterionic salt not only has much lower conductivity than NaCl but has also been shown to help solubilize proteins that are prone to aggregation.9,10... 

Fig. 17 XRPD patterns of the product obtained from an attempt to prepare a glutamate salt (top) and glutamic acid (bottom).

The sodium salt form of glutamic acid is monosodium glutamate (MSG). The neurotoxic levels of MSG have been studied extensively in animal and human models. The available data indicate that, under normal conditions, mammals have the metabolic capacity to handle large oral doses of MSG. Glutamate salts have also been tested in exercise. 

A seasoning is anything that enhances in flavor or appearance, or gives reflsh to foods. Spices, condiments, and salt or monosodium glutamate (MSG) are all seasonings (see Amino acids (msg)). 

Defatted peanuts are high in protein, low in moisture, contain only 20% of the naturally occurring fat, and have better stability than whole peanuts. Monosodium glutamate (MSG) has been used as a flavor enhancer for defatted nuts, but the result has not been entirely satisfactory as the addition of MSG produces a meaty rather than nutty flavor. This meaty flavor is more compatible with salted butter and nuts than with candy. 

An estimation of the amount of amino acid production and the production methods are shown ia Table 11. About 340,000 t/yr of L-glutamic acid, principally as its monosodium salt, are manufactured ia the world, about 85% ia the Asian area. The demand for DL-methionine and L-lysiae as feed supplements varies considerably depending on such factors as the soybean harvest ia the United States and the anchovy catch ia Pern. Because of the actions of D-amiao acid oxidase and i.-amino acid transamiaase ia the animal body (156), the D-form of methionine is as equally nutritive as the L-form, so that DL-methionine which is iaexpensively produced by chemical synthesis is primarily used as a feed supplement. In the United States the methionine hydroxy analogue is partially used ia place of methionine. The consumption of L-lysiae has iacreased ia recent years. The world consumption tripled from 35,000 t ia 1982 to 100,000 t ia 1987 (214). Current world consumption of L-tryptophan and i.-threonine are several tens to hundreds of tons. The demand for L-phenylalanine as the raw material for the synthesis of aspartame has been increasing markedly. 

In Foods. Each amino acid has its characteristic taste of sweetness, sourness, saltiness, bitterness, or "umami" as shown in Table 13. Umami taste, which is typically represented by L-glutamic acid salt (and some 5 -nucleotide salts), makes food more palatable and is recognized as a basic taste, independent of the four other classical basic tastes of sweet, sour, salty, and bitter (221). 

The existence of protein receptors in the tongues of mice and cows have been shown. Monosodium L-glutamate MSG [142-47-2] is utilized as a food flavor enhancer in various seasonings and processed foods. D-Glutamate is tasteless. L-Aspartic acid salt has a weaker taste of umami. Glycine and L-alanine are slightly sweet. The relationship between taste and amino acid stmcture has been discussed (222). 

JECEA reviewed the safety studies of glutamate and endorsed its safety by allocating an Acceptable Daily Intake (ADI) for L-glutamic acid and its monosodium, potassium, ammonium, calcium, and magnesium salts as being "not specified." The scientific committee for food of EC concurred (40). 

These limitations have been overcome by the development of strains able to grow well in a minimal salts medium in the absence of complex nutrients and vitamins. The carbon source is usually glucose and a complex nitrogen source, such as glutamate, can replace ammonia. 

The salt ions are captured by the ion exchange membranes that are present. The applications are limited to desalting amino add solutions, eg removal of HQ from L-glutamic add solution. 

Sensory receptors expressed in particular in taste receptor cells of the taste buds that sense the five basic tastes salt, sour, sweet, bitter and umami (glutamate taste). Sodium type ion channels sense salty taste whereas sour taste is transduced by potassium type ion channels. The underlying cause of sweet, bitter, and umami tastes is the selective activation of different groups of G protein coupled receptors that discriminate between sweet, bitter, and umami tasting molecules. 

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