Unlike gas chromatographic methods for trans fat analysis in fats, infrared analysis does not require any sample preparation
By January 2006, nutritional labels on foods will include the trans-fatty acid content.
Although trans-fatty acid occurs naturally in many fats, hydrogenated oils can contain three times more trans fat or as much as 35%.
As a result, the vegetable oil industry is developing new processing procedures to minimise the formation of trans-fats.
The official analysis methods from the American Oil Chemists Society (AOCS) and the Association of Official Analytical Chemists (AOAC) are either infrared absorption spectroscopy or gas chromatography.
Unlike gas chromatographic methods for trans fat analysis in fats, infrared analysis does not require any sample preparation.
A small amount sample is placed on the ATR crystal and the intensity of the absorption is measured at 966cm-1.
This band is unique to unsaturated fatty acids.
The saturated and unsaturated fatty acids do not absorb infrared energy at this wavenumber.
Wilks Enterprise has developed a unique portable, rugged, easy to use and relatively inexpensive infrared spectrometer, the InfraSpec VFA-IR, that brings the trans-fatty acid measurement out of the laboratory to where it is needed - in the production area, on a loading dock or in a warehouse.
Using the InfraSpec VFA-IR spectrometer for at-line measurements enables process changes such as lowering the temperature during hydrogenation or catalyst recycling to be quickly tested for their effectiveness in lowering trans fat levels.
The InfraSpec spectrometer is said to be easy for the operator in the production area to use since a numeric value in percentage trans fat is displayed.
The InfraSpec VFA-IR spectrometer is a new concept in infrared instrumentation, says Wilks.
It utilises a patented design consisting of an ATR sample plate with an elongated, electronically modulated source on one end and a linear variable filter (LVF) and linear variable array on the other.
The result is a compact spectrometer with no moving parts, no optical path exposed to air that is portable and rugged.
The software includes an internal calibration program that allows for simplified screen interface that give a digital readout in percentage trans fat for non technical end users.
