Question: what are food additive numbers?
Answer: 100 to 199: Food colouring. ... 
200 to 299: Preservatives. ... 
300 to 399: Antioxidants. ... 
400 to 499: Thickeners, emulsifiers and stabilisers. ... 
500 to 599: Acidity regulators and anti-caking agents. ... 
600 to 699: Flavour enhancers, including monosodium glutamate (E621) or MSG.