The functional role of lipids on the structure development of bakery products

An example of typical food processing is the manufacturing of bread. Breadmaking is probably one of the oldest technologies known to mankind. Findings suggest that people of Babylon, Egypt, Greece and Rome used bread as part of their diet many decades B.C. It is a staple foodstuff, which is made and eaten in most countries around the world. Bread products have evolved to take many forms, each based on quite different and distinctive characteristics. Over the centuries craft bakers have developed our traditional bread varieties using their accumulated knowledge as to how to make best use of their available raw materials to achieve the desired bread quality. In some countries the nature of breadmaking has retained its traditional form while in others it has changed dramatically. Bread is a unique food historically, and is the reason for the predominance of wheat as the world’s most highly prized cereal. Wheat has not the productive capacity of rice or maize, nor is it as nutritionally complete as oats. But wheat has unique proteins (those of rye are inferior) which form gluten and from the bakers' ingenuity in manipulating the gluten structures formed within the dough. The rubbery mass of gluten with its ability to deform, stretch, recover shape and trap gases is very important in the production of bread and all fermented products. Of all the cereals, wheat is almost unique in this respect. While there are many different breadmaking processes, they have the common aim of converting wheat flour and other ingredients into a light, aerated and palatable food. Bread quality is determined by the complex interactions of the raw materials, their qualities and quantities used in the recipe and the dough processing method. Although bread making has largely been studied, there is a lack among relations between ingredients and product structural changes. Aim of this study has been a better understanding and controlling a food process such as bread-making, in order to define the optimal working conditions in terms of process- product interactions. In particular, the attention has been focused on the influence that components of doughs have on dough development during bread processing. The present work takes account of two main phases of the production of a baked product: leavening and baking. An integrated approach has been tried to all phases of process so as to allow a complete optimization. In order to measure the most significant variable of dough state at macroscopic scale (loaf expansion) and to investigate structural modifications and their dynamics, non destructive digital imaging method (DIA) has been employed. This phenomenological hypothesis, which it has been considered to be realistic and to have general application, has been translated into mathematical models. In fact, a mathematical model has been set up to predict product properties as a function of both process variables and raw materials. The great advantage of predictive models is the possibility of avoiding expensive and time-consuming tests necessary to get enough information to treat the obtained data statistically. Models are quick and economical ways to assess food performance objectively. If used properly, mathematical models can be an appropriate and useful tool for food technologists. Due to the inherent difficulties of the process considered, selecting a suitable model has not been easy. Models of a single phase of process (fermentation) have been evaluated. In our situation, an empirical way has been used, because the macroscopic variable (assumed to be relevant for the process) follows a sigmoid pattern with time and there are well-fitting, useful empirical models of bacterial curves that can be applicable.