Pulsed NMR Method for Solid Fat Content Determination in Tempering Fats, Part I: Cocoa Butters and Equivalents

✍ Scribed by Petersson, B. ;Anjou, K. ;Sandström, L.

• Publisher: John Wiley and Sons
• Year: 1985
• Weight: 573 KB
• Volume: 87
• Category: Article
• ISSN: 0931-5985
• DOI: 10.1002/lipi.19850870603

✦ Synopsis

A general pre-treatment and measuring procedure is described for Solid Fat Content (SFC) determination with pulsed NMR on tempering fats (i. e. Cocoa Butters and Cocoa Butter Equivalents). These fats need a careful pre-treatment to reach their stable @-polymorphic form and crystal size. The different stepsin theanalysis werestudiedandoptimized togivereliableand quick results. Critical steps were found to be how to start the crystallization from the melted fat and the tempering process. The fat sample should be completely meltedat 800 C and held at 600 Cfor20 min. Commencement of crystallizationiscarriedoutat PCfor90minand temperingat26..5"Cfor40 hours. Cooling is carried out at 00 C for 90 min before the serial measuring procedure with 3.5 midbath using 10,20,25,27.5,30,32.5,35,40 and 600 C baths. Only the liquid signal is measured (indirect method) and 1 puls with 6 sec trigger time used. The temperature dependence of the signal is compensated with a liquid soya oil. The standard deviation for the described method was0.3-1.8%(abs)withthehighestdeviationsattemperaturesinthe very intensive melting range, showing that the temperature accuracy and stability in these baths is of greatest importance. A method to check the tempering process with SFC determinations at 26.5" C for various tempering times is also proposed.