Abstract

Monosodium glutamate (MSG), more specifically monosodium L-glutamate, is used in large quantities as a flavor enhancer throughout the world. The world capacity for production of MSG continues to increase. Demand is expected to increase in developing countries as its use in commercially prepared packaged foods, ready-made soups, and as a table seasoning increase Monosodium L-glutamate, , crystallizes from aqueous solution at room temperature as rhombic prisms. Commercially preferred crystals for use as flavor enhancement are obtained by crystallization in the presence of amino acids such as alanine. Glutamic acid-producing microorganisms are distributed widely throughout the natural environment. They are classified taxonomically as the Micrococcus, Brevibacterium, Corynebacterium, and Aerobacter sp. and Microbacterium genera. Most of these microorganisms are gram-positive, nonspore-forming, nonmotile, and require biotin for growth. The carbon sources for biosynthesis of glutamic acid include acetic acid and the commonly used carbohydrates. For industrial production, molasses and starch hydrolyzate are generally used at present. Monosodium L-glutamate elicits a unique taste, known as umami, which is different from the four basic tastes of sweet, salty, sour, and bitter. L-Glutamic acid is employed as a pharmaceutical and raw material for cosmetics. The acute toxicity of MSG is low. The main use of MSG is as a food ingredient. No specific toxic effects, and no evidence for carcinogenicity or mutagenicity have been demonstrated.