Study of the effects of smoke flavourings on the oxidative stability of the lipids of pork adipose tissue by means of Fourier transform infrared spectroscopy.

Pork adipose tissue was dry-salted for 24 h and then smoked by immersion in two liquid smoke flavourings for 1, 2 or 3 min. Both unsmoked and smoked pork adipose tissue samples were submitted to oxidative conditions at 70 °C in a convection oven with circulating air. Melted lipids of both samples were studied by Fourier transform infrared spectroscopy. Duplicate spectra were collected each day of the experiment by applying a film of melted lipids between two KBr disks. Changes in frequency values of different bands and in ratios between absorbances of some bands allow oxidation degree and oxidative stability of the samples to be determined. The usefulness of this technique for monitoring the oxidation process of pork adipose tissue lipids is shown. The greater oxidative stability of smoked pork adipose tissue samples in comparison with unsmoked samples is proved.