Maths Makes Crispy Cereals
by
Mark McGuinness
MCS, Victoria University of Wellington
Coauthors: Colin Please (University of Southampton), Neville Fowkes (University of Western Australia)

Moisture penetration of whole cereal grains is the critical process when cooking breakfast cereals before rolling, toasting, mashing, clumping or doing other mysterious things to the grains to make them into the various cereals you face each morning at the breakfast table. Wetting takes longer than heating, and it is important for the crispiness of the final product that the grain be cooked just so. A mathematical model of moisture penetration that allows for grain swelling and for the cooking reaction at the wetting front is derived in the form of a nonlinear diffusion equation. Asymptotic methods are used to solve the model. A mean action time is a lso derived, which is effectively a time to wet the grain, in the nonswelling case. There is an interesting difference between the asymptotic results and the exact mean action time results, which is resolved with the help of numerical solutions (using Fastflo) and with the help of further analysis.

Date received: March 14, 1999