Microstructural Studies in Fat Research

Microstructural studies play an important role in establishing the relation between composition, processing and final properties of many food products. In order to arrive at a full description of microstructure many visualization- and preparation techniques are needed. A number of fatty products such as shortenings, margarine , butter, and low fat spreads are discussed from a microstructural point of view. Examples of the influence of process parameters on microstructure and rheological properties are given. In particular, attention is paid to the fat crystalline matrix and the emulsion structure. Further, a new methodology is described making it possible to study interactions of emulsifiers at interfaces between oil and water. In this context , the displacement, at a planar interface, of sodium caseinate by low-molecular mass emulsifiers such as monoacylglycerols and phospholipids has been studied. It appears that saturated monoacylglycerols are more active in displacing the protein than unsaturated monoacylglycerols. With phospholipids, complicated phenomena such as spontaneous emulsification, occur at the oil / water interface . Phospholipids , in general, appear to be much more surface-active than monoacylglycerols. This type of work generates ideas to control and manipulate the microstructure and product properties of fatty products

Structure and Function of Food Products: A Review

A proper understanding of the behavior of food products requires knowledge of its structure, i.e., the spatial arrangement of the various structural elements and their interactions. The structure can properly be studied by visual observation techniques. In products such as fat spreads, creams, dressings, cheese, bread , milk , yoghurt , whipped cream, and ice cream , different structural elements can be distinguished. A number of those elements a re discussed, viz. , water droplets, oil droplets, gas cell s, particles, fat crystals and strand s. In addition examples of interactions between structural element s are presented, viz., oil droplets/matrix, protein/ protein, protein carbohydrate, and fat crystal/ fat crystal interactions. Finally, it is indicated how these elements cooperate in the formation of structure and contribute to function and macroscopic behavior of food products. Particular attention is given to fat spreads, processed cheese, protein gelation, and examples of the mutual interaction of milk proteins and of carbohydrates with milk proteins. It is expected that a proper understanding of the relation between structure and function will help us to design new ways of structuring in our continuing efforts to manufacture high quality, healthy and tasty food products

Economic vs. juristic thinking in Carl Menger’s principles of economics

Austrian Economic School is increasingly being treated as one of the most significant and ever more influential bodies of ideas affecting the contemporary economic science. It is well known that Carl Menger, the founder of the Austrian School, was a lawyer by education. The paper is devoted to the degree to which his legal education influenced his economic theorizing. After a close examination of the Menger’s conceptual apparatus and the epistemological ramifications of the key notions underlying his thinking, the paper concludes that the juristic background of the far-reaching theoretical contributions contained in Menger’s Principles was truly decisive. That holds true despite the fact that Menger only exceptionally utilized the juristic vocabulary. The key ingredients of his theoretical creation? such as the individual autonomy, the coincidence of the wills in concluding a contract the effective protection of property and making transactions based on the individual motivation to further one’s own interests to the utmost? are clearly inspired and in many ways influenced by private law, particularly the doctrines underlying the Roman Law and the Austrian Civil Code

Tras las huellas del empresario schumpeteriano: el caso de José Martínez Rivas (1872-1913)

Este artículo tiene dos objetivos: analizar la figura empresarial de José Martínez Rivas, protagonista destacado del proceso de industrialización vizcaína, y aplicar herramientas procedentes de la teoría económica para una mejor comprensión de la historia empresarial española. A partir de fuentes de archivo se reconstruye la actividad económica de este hombre de negocios y el destino de su riqueza. El trabajo se divide en tres partes. En el primer apartado se estudia el origen y primeros pasos de las principales iniciativas empresariales que llevó a cabo José Martínez Rivas. En el segundo, se describe la marcha y resultados de cada una de ellas. En el tercero, se emplea la concepción que J. A. Schumpeter tenía de la función empresarial para analizar la actividad de este empresario. Unas conclusiones finales resumen las principales aportaciones del trabajo y abren una puerta a futuras investigaciones relacionadas con el tema tratado y la teoría empleada.This article has two objectives: to analyse a leading businessman, José Martínez Rivas, a distinguished leader of Biscayan industrialization, and to apply economic theory to his case for a better understanding of Spanish business history. The business life of Martínez Rivas and the evolution of his fortune has been reconstructed with archive sources. The article is divided into three parts. The first section examines the origins and first years of his main business activities. A second section describes the evolution and results in each of these. A third and final part, applies Schumpeterian entrepreneur theory to Martínez Rivas? business initiatives. The conclusions summarize the main contributions of this work and open a door to further related research and the theory applied.Publicad

Microstructure of Shortenings, Margarine and Butter - A Review

Fat spreads are composed of liquid oil, fat crystals and water. The fat crystals in these products give the product the required consistency and stabilize the water droplets. Shortenings are waterfree products , the rheology of which depends on the solid fat content and interactions between fat crystals. Size and interaction between crystals is influenced by both composition and processing. Crystals form a three - dimensional network. Recrystallization phenomena, especially formation of large beta- crystals , can create product defects like sandiness. Margarines and halvarines are water- in - oil emulsions and have a relatively simple product structure. Because of the wettability of fat crystals, part of the solids are present in the water/oil interface, and influence the stability of the emulsion. Depending on the type of application, tropical margarines, table margarines, halvarines , puff-pastry, c reaming margarines, etc. , the ratio of solidlliquid and water content can be varied. No essential differences exist in the microstructure of products for different applications. Butter differs in its microstructure from margarines because of different processing and raw materials. Butter still contains a number of fat globules (derived from the cream) in its final product structure. These globules are dispersed in a matrix of fat crystals and oil desc ending from fat globules that were broken during churning. Also the moisture is present in different forms ranging from droplets to free moisture . Differences in microstructure can be introduced by different processing regimes

Structure Formation in Acid Milk Gels

The structure formation in acid milk gels is influenced by many factors such as heat, salt system, pH, culture and thickening agents. Understanding of the mechanism of structure formation is important in order to be able to influence the final texture of these products. In the present study the network formation in acid milk gels during acidification is monitored by freeze-fracture electron microscopy. Network formation appears to be a much more complex process than just an aggregation of the original milk casein micelles; it is accompanied by subtle dissociation and association phenomena of the milk caseins. The observed sequence of events can be explained from the course of the zeta potential , the association of the beta casein, the release of colloidal calcium phosphate from the micelle, the influence of heat treatment and from some observations on the internal structure of the casein micelle