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This paper reviews the identification of the various levels of structure present in milk fat crystal networks, and the development of analytical techniques to quantify these levels. The relationship of the various levels of structure to macroscopic physical indicators of the mechanical strength of the network is discussed. The analysis of the microstructural level of the network via fractal geometrical methods is outlined, as well as mechanical models relating the structure to mechanical properties. The effect of processing conditions on the different levels of structure and mechanical properties also discussed.

Sir:There are two types of standard methods developed by the AOCS and the IUPAC for the determination of solid fat content (SFC). The first method is for nontempering fats (AOCS Cd 16-93/IUPAC 6.2.2.1), and the second method is for tempering fats (AOCS Cd 16-81) such as cocoa butter. The tempering method is typically used in situations where the fats are known to crystallize into a wide variety of polymorphic forms. Tempering the fat induces the formation of the most stable polymorphic form in fat crystals.A study was conducted in our laboratory to investigate the effects of cooling rate on the final SFC of anhydrous milk fat (AMF), cocoa butter, and vegetable shortening using standard and controlled rate methods. Controlled cooling rates of 0.1, 0.3 (AMF only), and 1°C/min, as well as a fast quench/plunge were used to crystallize these fats prior to SFC determination.