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

The Phase Space as a New Representation of the Dynamical Behaviour of Temperature and Enthalpy in a Reefer monitored with a Multidistributed Sensors Network

The study of temperature gradients in cold stores and containers is a critical issue in the food industry for the quality assurance of products during transport, as well as forminimizing losses. The objective of this work is to develop a new methodology of data analysis based on phase space graphs of temperature and enthalpy, collected by means of multidistributed, low cost and autonomous wireless sensors and loggers. A transoceanic refrigerated transport of lemons in a reefer container ship from Montevideo (Uruguay) to Cartagena (Spain) was monitored with a network of 39 semi-passive TurboTag RFID loggers and 13 i-button loggers. Transport included intermodal transit from transoceanic to short shipping vessels and a truck trip. Data analysis is carried out using qualitative phase diagrams computed on the basis of Takens?Ruelle reconstruction of attractors. Fruit stress is quantified in terms of the phase diagram area which characterizes the cyclic behaviour of temperature. Areas within the enthalpy phase diagram computed for the short sea shipping transport were 5 times higher than those computed for the long sea shipping, with coefficients of variation above 100% for both periods. This new methodology for data analysis highlights the significant heterogeneity of thermohygrometric conditions at different locations in the container

The Effect of Processing on Some Microstructural Characteristics of Fat Spreads

The processing and the composition of fat spreads determine to a large extent the final product properties such as hardness, spreadability, mouthfeel, emulsion stability and salt release. In establishing the relation between composition, processing and final product properties, microstructural studies play an important role. In this context the influence of some process parameters in the production of shortenings and 80% fat spreads on microstructure and product properties has been investigated. Shear, cooling regime and crystallization conditions influence both the emulsion structure and the fat crystalline matrix. In general, working leads to softer products with a more granular crystalline fat matrix, whereas the water droplet size distribution is influenced in a complicated manner by the conditions of shear. This type of work indicates ways to control and manipulate the microstructure and product properties of fat spreads