Gun puffed cereal

Gun puffing is another method of suddenly subjecting a product piece to a disequilibrium. In this case, the product is heated under pressure in a close vessel. The most commonly used cereals for production of puffed grains are wheat and rice.

In order to make shape for puffing one must cook the grain formulation, form it in a forming extruder into the desired shape, dry the shapes to a very narrow moisture range and temper them. All this must be accomplished before gun puffing can take place.

When the vessel is suddenly opened, a violent decompression causes moisture to flash, inflating the product in much the same way as in direct expansion puffing.

Regular white or parboiled rice with less than 0.5% fat is commonly gun puffed. Rice has excellent expansion characteristics because of its starch properties.
Gun puffed cereal