Food Lipids: Chemistry, Nutrition, and Biotechnology

fication and blending on butterfat–canola oil and found that a linear increase in the
proportion of canola oil did not lead to a linear reduction in dropping point.
3. Nuclear Magnetic Resonance
The amount of solid triacylglycerols in a lipid sample can be determined by means
of NMR techniques. Laning [14] demonstrated the effect of chemical interesterification
on palm, palm kernel, and coconut oils. Random interesterification resulted
in modest solid fat content (SFC) changes, while directed interesterification produced
more significant increases, attributable to the increase in trisaturated triacylglycerols.
Generally speaking, interesterification results in more linear profiles, owing to the
greater variety of triacylglycerol species [68].
Blending of butterfat with canola oil produced slight changes in the solid fat
content of butterfat–canola oil blends, as exemplified by a contour profile (Fig. 13)
[34]. No changes greater than �6% were evident. The biggest increase in solid fat
content produced by interesterification was of butterfat at 25�C; SFC ‘‘valleys’’ were
present for the 80% butterfat–20% canola oil blend at 15�C, while the largest decreases
were present for the 40% butterfat–60% canola oil blend at 10�C.
4. Differential Scanning Calorimetry
DSC is used to measure the melting or crystallization profile and accompanying
changes in enthalpy of fats. Rost [69] described the directed interesterification of
palm oil. Calorimetry results indicated that the melting thermogram for noninteresterified
palm oil consisted of two main peaks centered around 10�C and 19�C. Di-
Figure 13 Contour profile of the effect of chemical interesterification on the SFC of butterfat–canola
oil blends. Each line represents a 1% change in SFC. (Adapted from Ref. 34.)
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