Physical properties, fats shortenings

Effects of Tempering on Physical Properties of Shortenings Based on Binary Blends of Palm Oil and Anhydrous Milk Fat During Storage... 

Hydrogenation is the most widely used and practical method of preparing fats and oils capable of imparting essential physical and functional properties to shortening. It is presently used to modify and stabilize marine, animal, and all types of vegetable oils. An excellent synopsis of batch and continuous hydrogenation processes is presented by Edvardsson and Irandoust (12). 

Physical properties of a shortening include appearance, consistency, solid fat content, crystal form and size, melting point, and melting behavior. These properties are influenced by the chemical composition which in turn relates to the nature of the fatty acids present and their distribution on the glycerol molecule. 

In this study, shortenings based on blends of PO and milk fat were produced to take advantage of the versatility and functionality of PO and the desirable buttery flavor of milk fat The effects of tempering on the physical properties of these shortenings during storage were investigated. 

Commonly used interesterified fats, whieh provide suitable fimctionality for the food industry, include fats that are rich in the long-ehain SYK, palmitic acid (16 0) and stearic acid (18 0) [77]. Chemical and enzymatic interesterification has been specially used in the formulation of margarines and shortenings to provide products with no TFA but that still maintain physical properties, taste, and stability [80]. 

Texture has been defined as the way in which various constituents and structural elements are arranged and combined into a micro- and macrostructure and this structure is externally manifested in terms of flow and deformation [1], The structural elements of fats consist of solid fat crystals. They are suspended in liquid oil and when present in sufficient quantity form a three-dimensional network that imparts plastic properties to the fat. The external manifestations of this network structure include a number of physical and mechanical properties such as hardness, softness, spreadability, brittleness, shortening power, and aeration properties. 

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