Simplified fatty acid classification

The main fatty acids are listed below together with two simplified groupings.

Method I will be used further in this chapter.

Method II is used mainly in the confectionery industry.

In classification method 1 there are 3 types of saturated fatty acids (short, middle and high) and two types of unsaturated fatty acids (cis and trans configuration). For simplification we did not take into account the cis-trans configurations in a C18.2 or C18.3 fatty acid (only low levels).

Simplified triglycerides according to the method 1

A triglyceride is a combination of the glycerol molecule with the 3 (different) fatty acids:

H3 = a triglyceride with the 3 H-fatty acids
H2M = a triglyceride with two H-fatty acids and one M-fatty acid
H2E = a triglyceride with two H-fatty acids and one E-fatty acid
H2U = a triglyceride with two H-fatty acids and one U-fatty acid
H2Sh = a triglyceride with two H-fatty acids and one Sh-fatty acid
HM2 = a triglyceride with one H-fatty acid and two M-fatty acids
Etc.
U3 = a triglyceride with 3 U-fatty acids

The melting point of the triglyceride depends on the length of the saturated fatty acid (the longer the higher the melting point) and on the saturation versus unsaturation (H3 has a much higher melting point than U3). Following indications of the melting point can be given:

H3 55-70°C (for 100% present in fully hardened BO or PO)
H2M 35-50°C
H2E 30-45°C
H2U/H2Sh 30-35°C

The more unsaturation the lower the melting point; U3 is fully liquid even at 0°C.

A fat is always a mixture of a large number of different triglycerides. Although we use “melting point” to specify a fat, the fat shows more a melting curve (percentage of crystallised fat as function of temperature as given by the N-line).

Fats wit the same melting point can have different melting curves or N-lines.

The groups of triglycerides, of which the melting point has been indicated above, are present in a fat in a low to a high level and are also partially dissolving in the more liquid part of the fat.

Because each fat has its own triglyceride composition, it has also its won N-line, crystallisation parameters and its own crystal network. Fats wit the same N-line but different triglyceride composition can show after crystallisation different hardness value or plasticity.

Examples of simplified triglyceride compositions of a number of different fats are given in the table below.

Back to top