See if the label in the package is complete and clear. First of all, see whether the packaging is neat and clean, whether the handwriting printing is clear, whether the label is complete and regular. The labels of canned food produced by regular manufacturers are complete and clear. They should be marked with product name, factory name, factory site, ingredient list, net content, solids content, standard code, quality grade and shelf life. Secondly, we should choose products within the warranty period. In addition, it depends on whether canned food is deformed or not. The terminology is "fat listening" or "missing listening".
See if the ingredient list contains preservatives. There are many kinds of additives as preservative food, such as sorbic acid, benzoic acid, etc. But according to the relevant regulations of the state, canned food can not contain preservatives. Some illegal enterprises use preservatives to cover up the improper management of hygienic environment in food processing, inhibit the reproduction of microorganisms in food, so as to prolong the shelf life of food.
See if the color is natural. Edible pigments are allowed to be used in some canned foods, but the amount and scope of use must be controlled within the national standards. At present, some illegal enterprises on the market use pigments beyond the standard, or beyond the scope of the use of pigments, and even use national standards do not allow the use of pigments in canned food, such as amaranth, lemon yellow, carmine, etc.