So when you buy marinated vegetables outside, try not to buy reddish pulp. Follow-up: This dyeing is related to Sudan red, but not nitrite. Answer: Sudan red was only used at that time, and nitrite has always been used in meat processing. I can only tell you that in the national standard, the amount of nitrite in braised pork should not exceed 0. 1.5g/kg, and the residue should not exceed 30mg/kg. Follow-up: I don't want to know what people put in, but I want to know the amount of sodium nitrite produced by salt in that process ... Answer: It seems that no one has specifically measured this, but nitrite in kimchi is generally studied more. In addition, there is no accurate figure whether the nitrite produced will be used with different salt content and different storage time. Even if there is nitrite in the marinated vegetables, it is far less than expected, so there is no need to study this part specially.