Monosodium glutamate. This is used as a flavour enhancer in Chinese and Japanese cookery but should be used sparingly. In Chinese markets it may be called mei jiung. (this is actually a brand name in Japan, the headquarters : http://upload.wikimedia.org/wikipedia/ja/thumb/0/0f/AJINOMOTO_Co.jpg/800px-AJINOMOTO_Co.jpg.
