Why does popcorn maize burst in such an explosive and fascinating manner? Scientists from the Institute of Food Research in Norwich will be demonstrating the interesting properties of maize in classrooms around Norfolk during National Science Week (16-23 March).

We eat maize as sweet corn and popcorn, but it is also present in many food products including breakfast cereals, tortillas chips and custard powder. GCSE students at five high schools will consider how maize has developed as an agricultural crop over the last 6000 years, and look at how the internal structure of the grain affects its ability to pop. The critical factors for good popping corn are the strength of the outer casing, the water content and the arrangement of starch inside the kernel. When heated, the tightly packed starch granules melt inside the hard outer casing, and the water in the starch turns to steam. Eventually the steam pressure bursts the kernel, and the molten starch foam flows out and sets in the characteristic flower shape as it cools.

"Popcorn is a snack food in the UK, but popping is an important food processing technique in the third world," says Dr Mary Parker, the electron microscopist at the Institute of Food Research, who is interested in how the structure of the grains affects food quality. "Staple grains such as sorghum can be popped, and the process exposes much more of the protein in the grain to the digestive enzymes, making the protein four times more digestible than in sorghum porridge", she added.

The students, at Attleborough, Hobart, Sheringham, Taverham and Costessey High Schools will also have the opportunity to see how studying science at school relates to a scientific career.

Other activities in Norfolk during Science Week can be seen here: http://www.bbc.co.uk/norfolk/your/extra/science_week/index.shtml 

Notes for editors:

• This project has been funded by a BBSRC science week grant.

• The mission of the Institute of Food Research is to carry out independent basic, and strategic research on food safety, quality, nutrition and health. It is a company limited by guarantee, with charitable status, grant aided by the Biotechnology and Biological Sciences Research Council (BBSRC).

• The Institute is based on the Norwich Research Park.

• ISDN Audio available.

• Photos available.

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