The most essential accompaniment for a typical movie-going experience is a bucket of popcorn. Popcorn, the ubiquitous comfort snack, is one of the few defined junk foods considered healthy. Popcorn is a whole grain and a good source of fibre.
Three cups of plain, air-popped popcorn weighs in at only about 95 calories. Popcorn has no definite past. It is widely believed to have originated in Mexico.
The Maya and Aztecs revered corn, making it a staple. It is believed that these ingenious people discovered the art of popping corn over open flames accidentally. Today, most of the world’s popcorn is grown in the US Corn Belt of Illinois, Indiana, Iowa, Kentucky, Michigan, Missouri, Nebraska and Ohio.
Heat does the trick
Popcorn is a whole grain maize product. Like all six types of corn, popcorn is a cereal grain originating from a wild grass. Its scientific name is Zea mays everta, and it is the only type of corn to actually pop. However, it is to be noted that only the kernels have the ability to pop. The Popcorn grain is composed of three main components: endosperm, germ and the pericarp (also known as hull or bran).
The endosperm is made up of soft and hard starch granules. It is a carbohydrate, which is always white or yellow. The function of the starch is to provide energy for the living part of the kernel, more commonly known as the ‘germ’ or ‘embryo’. The kernel’s outer hull is the pericarp, which is made up of cellulose. The pericarp is usually white or yellow too, though it could also be red, black and something in between.
The secret behind the popcorn phenomenon lies in the unique structure of the kernels, since each kernel contains a small drop of water stored inside a starchy core. As a snack, the most important factor for a popcorn kernel to turn into the nutritious snack we all love is heat, which helps it pop.
This can be achieved in a specialised popcorn machine, a pressure cooker, air fryer, microwave oven, or hot pan. Most popcorn will pop when the kernel’s internal temperature reaches 200-240 degrees Celsius. Bound within the endosperm is moisture. When the kernel is heated, that moisture turns to steam. Because the pericarp is hard and flinty, pressure builds up within the kernel.
The starch within becomes soft and the moisture vaporises until the pressure in the kernel reaches 135 pounds per square inch. The pressure increases until the pericarp ruptures and the gelatinised starch granules puff out. The kernel literally turns inside out. The starch or endosperm is the white part of the popped kernel and the pericarp is the darker, flaky bit at the centre. The resulting hot and light snack is then flavoured and served.