In a broad sense, puffed food refers to any food that uses techniques such as frying, squeezing, stir frying, baking, and microwave technology as a ripening process, and has a significant increase in volume before and after the ripening process. Puffing is a process that utilizes the principle of phase transition and gas hot pressing effect to rapidly heat up, vaporize, and expand the liquid inside the processed material, and relies on the expansion force of the gas to drive the structural denaturation of the polymer substances in the components, thereby making it a porous substance with a network like structure and a fixed shape. Puffed food refers to food produced through the puffing process.

High temperature puffing technology is a modern mechanical extrusion molding technology combined with relatively ancient processing techniques such as deep frying puffing and sand frying puffing to produce puffed food. Among them, new puffing technologies such as microwave puffing and baking puffing should also belong to this category.

Frying and puffing: It is the use of oily substances as heat exchange media to gelatinize starch, denature proteins, and convert water in fried food into steam, thereby maturing the food and increasing its volume. The oil temperature for frying and puffing is generally between 160-180 ℃, not exceeding 200 ℃.

Hot air puffing: including air flow puffing, baking puffing, and sand frying puffing, it uses air as a heat exchange medium to gelatinize the starch, denature the protein, and convert the moisture of the heated food into steam, thereby maturing the food and increasing its volume.