The combination of many forces exerts a key role in the stabilization of colloidal dispersions, in controlling attraction or repulsion among the dispersed entities. Such forces concur to stabilization, phase separation, coagulation, and are particularly evident in water-based systems. Their combination favors/hinders the association of colloids, and is often met in food sciences. The results one gets arise from the combination of van der Waals, electrostatic, sterical, osmotic and so forth. Some of them are attractive, other repulsive. Their combination ensures the onset of a given organization mode, as phase separation, if the repulsive forces dominate. Obviously, changes in the relative weight of such contributions favor aggregation or, conversely, dispersion. A worked example based on common knowledge is the milk manipulation chain, leading to cheese formation. That process arises from the combination of effects leading to aggregation, or, conversely, phase separation of casein and other milk components. Finally, maturing gives rise to fresh or seasoned cheese. The combination of attractive, van der Waals, vdW, and repulsive, as double layer, DL, but also sterical, ST, depletion and osmotic forces results in the dominance of aggregation versus dispersion modes. The overall effect depends on the concentration of colloid particles, on the forces amplitude, on their decay length and power laws. The combined role of such forces is at the basis of the well-known DLVO theory on colloid stability. The results predicted by that theory are finely tuned when vdW and DL forces overlap with sterical stabilization and, eventually, with depletion ones. The milk manipulation chain is a worked example of such intriguing association features. The different stages that are pertinent to each preparation step imply the dominance of one, or more, of those forces leading to the production of a selected cheese kind.
The transformation of raw food in something else, that could be properly stored, is well acquainted since the very early stages of human civilization. It is urgent, nowadays, to optimize the above transformations in such a way that the products obtained by any food manipulation chain are safe and can be stored for long times. That is the reason why efforts are currently done in the search to optimize the properties of primary matter in real food. To do this it is required that the most advances scientific approaches supplement what is done in current use procedures. These efforts actually find the due attention, which is also due to the fact that the amount of available food resources is not much higher if compared to the number of humans worldwide. Transformation of primary matter, thus, requires to be optimized in such a way to ensure the production of food(s) having good nutritional quality, safety and substantial attitudes to be stored even in non optimal conditions. The best way to proceed on this line relies on an incontrovertible fact. Most primary raw matter is usually transformed in products characterized by a colloidal nature. Hence, the latter take the form of pastes, creams, and semi-solid matter, whose consistency spans from that of yogurt to that of hard cheese.
If so, it is urgent to extend actual knowledge on colloid sciences to the food field. Theories on colloid stability are actually well acquainted and substantially developed. As mentioned above, we actually know in some detail what are the forces (energies) responsible for a given organization mode of raw materials into real food. Obviously, once the transformations have taken place. Some efforts along this line are actually in use from some scientists and producers. That is why we propose quantifying current knowledge in the field of colloids to selected cases. Given the relevance of such items for the national and international community, it is urgent to find systematic approaches, capable to solve the required demands. Our intention is to develop computational protocols capable to made realistic forecasts on all steps inherent to a given food production chain. From previous knowledge, it is known that each step in any food production chain is characterized by dominance of some form of force, hence by different energy terms. The most easy to handle mentioned above are:
1) surface adsorption;
2) wrapping;
3) sterical;
4) osmotic;
5) van der Waals;
6) electrostatic;
7) depletion.
We are aware of the fact that the contributions to the overall system stability due to the above forces can be substantially different, in modulus, each from the other. In addition, some such contributions are attractive (as van der Waals), other repulsive (as double layer ones). What is more, the effects due to each of them depend on distance, that is on the concentration of the dispersed matter, according to different power law modes. Think, for instance, to the substantial difference among van der Waals and double layer forces mentioned above! It is also important to check if it is possible to pass, and in which way, from a finely dispersed to a deeply coagulated state, as experimentally observed in some stages of food manipulation. All these aspects are particularly relevant in well proposed
With this in mind, it is evident that calculus procedures shall be possible only by considering the mentioned terms in a sort of hierarchical scale, that is by progressively adding one more term of minor relevance. In addition, "ad hoc" experiments on selected items, mostly dealing with enzyme action and ionic strength effects, will help defining what are the real contributions pertinent to each of the above energy modes.
Another reason for performing this research line arises by the fact that we are actually investigating the colloidal aspects inherent to safe food preparations, as it is briefly indicated in the enclosed literature. This is a promising field of investigation and would like to continue along this research line, mixing together theory and experiments.