Agino motto is monosodium glutamate. This is the sodium
salt of glutamate acid, one of the 22 amino acids found in protein.
It is produced by hydrolysis of protein, usually vegetable in origin and is therefore found in small amounts in many
foodstuffs naturally.
Debate has raged for decades on the health effects but all the evidence shows that unless you consume abnormal amounts the risk is minimal to none. The burning sensation some experience when eating Chinese has been attributed to MSG by some, but it may be the fermented soy sauce instead.
"From human studies, the experts noted that doses as high as 147 g/day produced no adverse effects in males when given for 30 days; in a 70 kg male that corresponds to 2100 mg/kg of
body weight."