Modification patterns in germinating barley--malting II.

Modification refers to breaking down of cell walls and the conversion of starch-to-sugars in the endosperm of grains by the action of enzymes released from the aleurone layer and possibly the scutellum during germination. Experimentalists have observed two completely different modification patterns in germinating barley. Based on an enzyme reaction, strongly nonlinear diffusion model developed in Part I of this series of papers on malting we examine simple models which predict modifications patterns similar to both observed patterns. We show that one of the observed patterns represents a natural propagation mode that acts as an attractor for the system. The speed of approach to this mode is strongly effected by initial conditions, a consequence of the enzymic nature of the reaction and the dramatic change of diffusivity brought about by the reaction.