Alimentos funcionales de origen animal con perfil lipídico modificado: estrategia, herramientas y diseño

Abstract

In recent years the interest of the food industries and the consumers by the concept of "functional food" has been increased. Due to the growing interest by the consumers for foods health, the food industry had understood the potentiality of functional foods` market. Consequently, these companies had been initiated an intense research activity in the area of functional foods all over the world. On the other hand, it should be emphasized that dietary fat is the nutrient whose has received most attention in recent years, due to the negative connotations that high consumption of dietary fat has for the human health. Nevertheless, some fractions of dietary fat are essential, because acts in both pathological and physiological processes, and consequently they have become the centre of many investigations directed to identify their negative and positive properties. In this work, functional foods were investigated by point of view of the health, but also in the perspective related with their manufacturing by the food companies, for which development of these foods means an important source of diversification. Besides, with the development of new functional products appears the need to develop reliable, simple and fast routine methods for the quantification of the modified nutrients in these products. In many cases, adequate methods for the determination of added nutrients in all food matrices does not exist. In other cases, it must be quantified nutrients that are natural in a food, but not previously determined because they were not in important quantities. Because the problem to address is very long, this work has focused on the study of fatty acids profile of functional foods on animal origin. It is well known that the intake of unsaturated fatty acids may reduce the risk of cardiovascular disease and possibly the incidence of some cancers, asthma and diabetes, among other diseases. On the other hand, animal-origin foods have been criticized for their high contained in saturated fatty acids, and they are considered harmful for the health. In this line, four research works related to the study of the lipid profile on animal-origin foods have been carried out. In the first study it was developed a functional meat-based food with a healthier lipid formulation with respect to conventional meats. Subsequently, a complete study of the product developed has been carried out, that included nutritional properties as well as physical-chemical and sensory characteristics and besides, its stability during the storage has been determined. Additionally, the results obtained for the new developed product were compared to those obtained for conventional products of the same type taken from retail markets. Typically, the design of functional foods presents concerns associated with the addition of functional components to the food, because we want to obtain functional foods similar to the traditional products and the functional ingredients are usually exogenous elements. Consequently, a second study was carried out in which the experiment design and the response surface methodology has been employed to obtain beef patties with texture similar to which counterparts obtained from retail markets, by the use of transglutaminase. A food can be considered as “functional” by itself if it contains beneficial effects for human health. Therefore, it has been considered fish as “functional itself”, according to its high content of omega-3 fatty acids. In this way, the third work of this thesis describes a comparative study between the nutritional properties and lipid profiles of wild and farmed turbot, due to that is known that the diet of the animals can influence the muscle lipid profile and in its nutritional values. Additionally, resistance to different antimicrobial agents of Aeromonas spp. and Pseudomonas spp. isolated of the muscle of the wild and farmed turbot has been compared. This type of comparative studies are necessary, considering the utilization of the extractive fishing has touched ceiling and that the increment in the aquaculture production is and will be necessary in the future to satisfy the world demand of fish. As it has been mentioned previously, it should be pointed, that nowadays there is a deficit of rapid, simple and accurate methods of routine for the determination of the nutrients of interest in the foods modified. This has carried us to the development of a rapid method for the quantitative determination of fatty acids in cow´s raw milk. This method allows to monitorize the lipid profile of raw milk when is necessary to obtain quickly results of a large number of samples, as for example, during studies of modification of the diet of the cattle conducted to modify the lipid profile of milk production.