**7. Conclusions**

In this chapter oscillatory rheological data are presented to highlight the structural changes of starch suspensions during heating and further storage. Furthermore, the viscoelastic behavior of different starch types with selected hydrocolloids is presented in order to understand and control rheology in food processing. Moreover, the rheological behavior of starch-hydrocolloid mixtures is described in complex systems, they contain them that aim at successful food product development.

Starches undergo significant changes under heating that are related to structural changes and can be determined using small amplitude oscillatory shear (SAOS) tests. In many research works these tests are also combined with rapid visco analyser (RVA measurements), viscosity values, texture analyses, microscopic observations, DSC thermographs.

Hydrocolloids alter the viscoelastic character of starch pastes and different mechanisms are proposed, some of them based on their interactions with starch polymers. Hydrocolloids are found in the continuous phase of the starch pastes changing the effective concentration of starch in the final mixtures. They can also immobilize the water available, or they can interact with starch polymers. Pastes containing hydrocolloids may be less structured and less solid-like than the control pastes. Specific interest presents their role in gelation and retrogradation, since they are considered anti-staling agents and can prohibit retrogradation effects, specifically those of amylopectin.

Controlled rheological properies can be achieved by changing hydrocolloid-starch mixtures in selected products such as sauces, soups and caramel sauces, e.g. the final quality of native starches white sauces can be maintained when appropriate thawing process under fast heating (microwaves) is used.

New kinds of hydrocolloids are going to be used and starch role especially that of native starches is re-defined. The interest about such systems is going to increase and research on this field will be continued.
