ABSTRACT

It is not easy to determine the real relationship between the rheological prop­erties and different protein structures. A better understanding of the inter­ actions between raw materials and engineering operations regarding the rhe­ ological properties in general, and of protein gels in particular, holds the key to their exploitation in terms of improved product quality and development of novel and improved processes. Each food processing idea encompasses the characterization of important properties of food materials that influence their behavior during processing as well as the design and development of improved and novel unit operation. For instance, the principal proteinaceous component of wheat flour responsible for the viscoelasticity of dough is gluten. Some dif­ ferences have been observed in the functionality of gluten from different wheat varieties. In the process of hydration, a still more complex pattern of behav­ ior is observed in which there is an immobile protein environment and sev­ eral different mobile environments. In dry gluten, a relatively highly mobile protein fraction environment depends on the origin of the gluten. The physi­ cal properties of interfaces are major determinants of stability (or instability) of food foams and emulsions, and rheology of proteins plays a crucial role here. Some proteins form a strong elastic interface to confer stability, while others, such as surfactants/emulsifiers, rely on rapid interfacial mobility (Mor­ ris, 2000). In the novel processing technologies, the influence of protein prop­ erties now focuses particularly on the structure of major food components, to­ gether with their interactions and relationships under changing environments. Nowadays, it is a matter of great importance in nanotechnology, which refers to technology based on the manipulation of individual atoms and molecules to build structures to complex, atomic specifications. As it was written (Swaine,

2 0 0 0 ), the hope of nanotech is not merely that technologies can be developed to manipulate atoms precisely to build tiny, useless artifacts, but rather that mechanisms be developed to generate vast amounts of useful nanostuff. This nanoscale is also referred to as nanorheology, which can be applied only to differentiate the properties at that level of understanding where different laws apply. There are many technical aspects where protein gels and even single molecules of this system can form building materials for nanoscale engineer­ ing projects. The most known being developed is a computer calculation sys­ tem based on proteins. It is most likely that engineers would just put the atoms where the description instructs, and then a describable atomic structure that did not defy the laws of physics could be manufactured at will (Swaine, 2000). A better understanding of the factors that determine the rheological proper­ ties of protein gels can help to identify possible methods of manipulation.