Puffed grain

Puffed grains are grains that have been expanded ("puffed") through processing. They have been made for centuries with the simplest methods like popping popcorn. Modern puffed grains are often created using high temperature, pressure, or extrusion.

People eat puffed grains in many ways, but it can be as simple as puffed grain alone and with sugar or salt for taste. Commercial products such as corn flakes and Corn Pops mix many ingredients into a homogeneous batter. The batter is then formed into shapes then toasted or extruded. This causes them to rise, but not puff or pop. Puffed grains can be healthful if plain, but when other ingredients are mixed with them they may lose some of their health benefits.[1]

Puffed grains are popular as breakfast cereals and in the form of rice cakes. While it is easy to recognize that cereals came from whole grains, the expansion factor for rice cakes is even greater, and the final product is somewhat more homogeneous.

History

In 1948 and 1950, ears of popcorn, up to 4,000 years old, were discovered by Harvard anthropology graduate student Herbert W. Dick[2][3][4] and Harvard botany graduate student Earle Smith,[5][6] in a complex of rock shelters,[7] dubbed the "Bat Cave",[8][9]

Manufacture

Puffed rice can be produced using the simple but effective method of hot salt frying. Salt is heated in a pan until it is hot enough to pop rice added to it within seconds. Parboiled or dried pre-cooked rice is added to the heated contents of the pan and stirred. Puffing starts almost immediately and completes in less than a minute and the rice is scooped out by a sieve.

High pressure puffed grain is created by placing whole grains under high pressure with steam in a containment vessel. When the vessel's seal is suddenly broken, the entrained steam then flashes and bloats the endosperm of the kernel, increasing its volume to many times its original size.

Puffed rice or other grains are occasionally found as street food in China, Korea (called "ppeong twigi" 뻥튀기), and Japan (called "pon gashi" ポン菓子), where hawkers implement the puffing process using an integrated pushcart/puffer featuring a rotating steel pressure chamber heated over an open flame. The great booming sound produced by the release of pressure serves as advertising.

Manufacturing puffed grain by venting a pressure chamber is essentially a batch process. To achieve large-scale efficiencies, continuous-process equipment has been developed whereby the pre-cooked cereal is injected into a high pressure steam chamber. It then exits the steam chamber via a Venturi tube to an expansion chamber, where the puffed cereal is collected and conveyed to the next process step. These devices, generally called stream puffing machines, were perfected in the latter half of the 20th century in Switzerland and Italy, but are now available from manufacturers in China as well.

List of puffed food

See also

• Flattened rice
• Rolled oats
• Bamba (snack)

External links

Riso soffiato 米香

• Research notebooks and papers of the inventor of the process of puffing rice and starches, Alexander P. Anderson, are available for research at the Minnesota Historical Society