Wim Lichtendonk

Understanding the link between GMP and dough: From glutenin particles in flour towards developed dough

Clear correlations exist for glutenin macropolymer (GMP) quantity and rheological properties vs. wheat quality and dough rheological properties, but real insight in understanding these links is still missing. The observation that GMP consists of glutenin particles opens up new possibilities to reveal the underlying mechanism linking glutenin network properties with dough preparation. GMP was isolated from flour of three wheat varieties: Estica, Soissons and Baldus, strongly varying in their mixing requirements (expressed as time-to-peak, TTP). Decrease of GMP quantity and G′ vs. mixing energy was confirmed. More detail was obtained by studying the changes in GMP particles when mixing flour into dough. Mixing leads to a decrease in the average size of the particles. Interestingly, the TTP coincided with the work-input at which all particles just became soluble in SDS. At TTP, the average size of the GMP particles was the same for each variety. During mixing particles lost their globule shapes and appeared ruptured. Particle size analysis confirmed that particles were still present near TTP. Analysis of the change in particle size vs. energy input using physical principles revealed the following: (1) mixing energy is the predominant actuator in decreasing GMP particle size; (2) the initial GMP particle size in flour strongly determines the practical mixing requirements; and (3) the derived mixing energy vs. GMP particle size relationship was shown to be applicable for both Mixograph and Farinograph mixing. Our results demonstrate that, for the flour samples used, glutenin particle size determines TTP and GMP rheology, showing that glutenin particle properties could be a new key to understand the link between GMP and dough properties.

Chapter 34:Mechanisms Determining Crispness and Its Retention in Foods with a Dry Crust

Various popular food products consist of a crispy crust and a non-crispy moist inner part. Well-known examples are many bread types and deep-fried battered snacks like fried fish. For the first type the crust has originally the same chemical composition as the rest of the food product, while for the...

Individual Fracture Events in Cellular Foods

Crispy foods like biscuits and breads crusts are cellular solids with relatively large pores of a wide size distribution. Important for the crispy character of such products are both the fracture behaviour and the acoustic emission (Luyten et al. [1]). With aging under deteriorating conditions, these products become less crispy. This is often ascribed to an increase in water activity of the crusts resulting in a change in the mobility of the different molecules, and thus a change in the solid material properties. However, it is difficult to relate directly the change in molecular properties to changes in crispy behaviour. One of the reasons for this is the product morphology, dry crispy foods are irregular built cellular solids. An example is given in Fig. 1.