It is against the food safety law to use non-edible substances or industrial raw materials such as caustic soda (sodium hydroxide, food-grade sodium hydroxide can only be used for cleaning and disinfection of tools and equipment in food processing), formaldehyde (formalin), hydrogen peroxide (hydrogen peroxide, food-grade hydrogen peroxide can only be used for cleaning and disinfection of tools and equipment in food processing) when processing bloating (tripe), pork tripe and pork intestines. Phosphorus-rich couplet (compound food additive) with QS certificate can be used legally and standardly, with complete three certificates, safe eating, crisp taste and high yield. Put the phosphorus-rich couplets into the pot where the tripe is cooked, simmer for 2-5 hours after cooking, and then take them out of the pot.