MSG vs flavouring

MSG and flavouring both are nouns.

Word	Noun	Adjective	Verb	Adverb
MSG	Yes	No	No	No
flavouring	Yes	No	No	No

As nouns, flavouring is a hypernym of MSG; that is, flavouring is a word with a broader meaning than MSG:

MSG: white crystalline compound used as a food additive to enhance flavor; often used in Chinese cooking
flavouring: something added to food primarily for the savor it imparts

Other hypernyms of MSG include flavorer, flavoring, flavourer, seasoner, seasoning.

MSG (noun)	flavouring (noun)
white crystalline compound used as a food additive to enhance flavor; often used in Chinese cooking	something added to food primarily for the savor it imparts