Pulsed NMR Method for Solid Fat Content Determination in Tempering Fats Part II: Cocoa Butters and Equivalents in Blends with Milk Fat

Abstract

AbstractEarlier, in part I of this paper, a method for Solid Fat Content (SFC) determination with pulsed NMR has been described for cocoa butters and cocoa butter equivalents. The present work (part II) is a continuation with these fats together with 10 to 30% milk fat. These fat blends need a modified pretreatment before NMR analysis. Crystallisation of the melted fat should be done at 0° C for 150 min and subsequent tempering performed at 19.0° C for 40 h. No other deviations from the earlier reported method have been carried out. Also SFC determination for chocolate has been described and used as a tool for the development of a proper NMR method, giving SFC on a pure fat blend more or less equal to SFC in corresponding milk chocolate. Different pretreatments (i.e. tempering temperatures) have given very different SFC results. A crystallographic understanding of these were achieved using X‐ray, microscope and thermal analysis techniques. The chosen tempering temperature 19.0° C gave a single solid solution, which is essential in chocolate if the right properties of the fat are to be reached. Differences in SFC on pure fat blends by different tempering temperatures could, in the same way, be found in milk chocolates stored at corresponding temperatures. Storage temperature can, to a certain degree, be chosen in order to optimize and control the SFC (i.e. properties) in a chocolate product. The choice of initial temperature especially will strongly influence the SFC in chocolate and the crystal lattice remains virtually unaffected by changes in storage temperature.