The high cost and time-consuming nature of farm inspections
and analysis of melted fat by gas chromatography (GC) prevents
the application of these quality control programs to all the animals
produced. Usually, in the slaughterhouse, one fat sample per animal
is taken for each batch (each batch being made up of between
30 and 80 animals). All these samples are then melted together and
a single GC analysis is performed. This method enables analysis of
batches but not of individual items, an important consideration
where the product, as in this case, commands high market prices.
The fatty acid profile of individual pigs may differ greatly from
the batch average. This – together with the costly and laborious
nature of the procedure involved – is one of the main disadvantages
of the traditional control system (Garrido-Varo, García-Olmo,
& Pérez-Marín, 2004).