General Description
Synonyms: Chinese seasoning; E621; glutamic acid monosodium salt; glutamic acid, sodium salt; MSG; monosodium L-glutamate monohydrate; natrii glutamas; sodium L-glutamate; sodium glutamate monohydrate; sodium hydrogen L-(þ)-2-aminoglutarate monohydrate.
Description: Monosodium glutamate occurs as white free-flowing crystals or a crystalline powder. It is practically odorless and has a meat-like taste.
Chemical Name: Glutamic acid monosodium salt monohydrate
Functions
Buffering agent; flavoring agent.
Uses
Monosodium glutamate is used in oral pharmaceutical formulations as a buffer and a flavor enhancer. For example, it is used with sugar to improve the palatability of bitter-tasting drugs and can reduce the metallic taste of iron-containing liquids.
It has also been used in subcutaneous live vaccine injections such as measles, mumps, rubella and varicella-zoster live vaccine (ProQuad).
However, the most widespread use of monosodium glutamate is as a flavor enhancer in food products. Typically, 0.2–0.9% is used in normally salted foods, although products such as soy protein can contain 10–30%.
The use of monosodium glutamate in food products has been controversial owing to the apparently high number of adverse reactions attributed to the substance, which gives rise to the so-called ‘Chinese Restaurant Syndrome’ .
The current consensus is that there is no clinically compelling evidence to suggest that monosodium glutamate may be harmful at the current levels used in foods.
Safety
Monosodium glutamate is widely used in foods and oral pharmaceutical formulations. It is generally regarded as moderately toxic on ingestion or intravenous administration. Adverse effects include somnolence, hallucinations and distorted perceptions, headache, dyspnea, nausea or vomiting, and dermatitis. The lowest lethal oral dose in humans is reported to be 43 mg/kg. The use of monosodium glutamate in foods has been controversial due to the so-called ‘Chinese Restaurant Syndrome’ , although it is generally regarded as safe at intake levels of up to 6 mg/kg bodyweight
Handling Precautions
Observe normal precautions appropriate to the circumstances and quantity of material handled. When heated to decomposition, monosodium glutamate emits toxic fumes of NOx and Na2O.