.........enamel is used for acidic foods 

1. Acid Resistant:- Acid Resistant Lacquer is a golden-colored enamel and can be coated with that is called R-enamel or AR cans. These cans are used to pack acidic fruits which are of two types (a) which contain water-insoluble colours, such as peach, pineapple, apricot, grapefruit and those containing water-soluble colours, for example, raspberry, strawberry, plum, and colored grapes, 2. Sulfur resistant:- This lacquer is also golden in color and cans coated with it are called C-enamel or S.R cans. These are for non acidic food only and should not be used for high acid products as the acid dissipates the lacquer. These cans are used for peas, com, lima bean, red beans, etc.