Cocoa Butter Solid Fat Content (SFC) Testing Experiment (Indirect Method)

Objective

 

Measure the solid fat content (SFC) of cocoa butter at different temperatures. This study uses the indirect method for SFC; the direct method can also be applied.

Materials

 

Cocoa butter sample; glycerol.

Instrumentation

 

PQ001 Solid Fat Content Analyzer, 10 mm coil; magnet temperature 40 °C; drying oven; water bath.

Sample Preparation

 

Melt cocoa butter in the oven, then use a pipette to transfer appropriate amounts of cocoa butter and glycerol into sample tubes.

Experimental Procedure

 

1) Place cocoa butter in the oven at 80 °C; hold for 15 min.

2) Transfer cocoa butter and the reference (standard) to a water bath at 60 °C; hold for 30 min.

3) After the 60 °C hold, record the NMR signal at 70 μs: S₆₀ for the liquid cocoa butter sample and R₆₀ for the reference.

4) Move the cocoa butter sample to a 0 °C water bath; hold for 90 ± 2 min.

5) Then hold at 26 °C in a water bath for 40 ± 0.5 h.

6) Return the sample to a 0 °C water bath; hold for 90 ± 2 min.

7) Measure SFC at the following eight temperature points (each hold 60 ± 1 min):

5 °C — hold 60 ± 1 min;

10 °C — hold 60 ± 1 min;

15 °C — hold 60 ± 1 min;

20 °C — hold 60 ± 1 min;

25 °C — hold 60 ± 1 min;

30 °C — hold 60 ± 1 min;

35 °C — hold 60 ± 1 min;

40 °C — hold 60 ± 1 min.

At each temperature T, record the 70 μs NMR signal of the cocoa butter sample (S_T) and of the reference (R_T).

Calculate the corresponding SFC using:

SFC(T) = 100 − (R₆₀ × S_T × 100) / (S₆₀ × R_T)

Where SFC(T) is the solid fat content at temperature T; S₆₀ is the sample signal at 70 μs after the 60 °C hold; R₆₀ is the reference signal at 70 μs after the 60 °C hold; S_T is the cocoa butter signal at 70 μs at temperature T; R_T is the reference signal at 70 μs at temperature T.

Solid fat content (SFC) results.