GC-C-IRMS analysis of FAMEs as a tool to ascertain the diet of Iberian pigs used for the production of pork products with high added value

Taste, quality and perceived health benefits result in a high demand for both green and mature pork products derived from the Iberian bred swine. These characteristics are directly related to diet and breeding style (free ranging in a particular Mediterranean ecosystem: the Dehesa). Given that current demand is not matched by the available resources, animal feed is increasingly used. GC-C-IRMS analysis of Palmitic, Stearic, Oleic and Linoleic Acid methyl esters allows for differentiating between pork raised in the traditional way and that fattened on animal feed. Although a value of delta C-13(C18:1) = -25.9 parts per thousand is a good discriminator, exploratory analysis of principal canonical components is required to properly assign any unknown sample.