Effect of different cooking methods on lipid oxidation and formation of free cholesterol oxidation products (COPs) in Latissimus dorsi muscle of Iberian pigs.

The aim of this work was to study the influence of different cooking methods (grilled (GR), fried (FP), microwave (MW) and roasted (RO)) on lipid oxidation and formation of free cholesterol oxidation products (COPs) of meat from Iberian pigs that have been fed on an intensive system. Moisture and total lipid content, TBARs, hexanal and COPs were measured in Latissimus dorsi muscle samples. Cooking did not produce changes in total lipid content in meat but induced significantly higher lipid oxidation (TBARs and hexanal values) (p<0.001) and cholesterol oxidation (COPs) (p<0.01). When the different cooking methods were studied, the grilled method was the least affected by lipid oxidation (TBARs and hexanal) compared to the others. There were no significant differences among different cooking methods on COPs values. The most abundant cholesterol oxides were both 7α-hydroxycholesterol and 7ß-hydroxycholesterol in all groups studied.

Isolation and identification of low molecular weight antioxidant compounds from fermented "chorizo" sausages.

This work is focused on the determination of low molecular weight compounds extracted from samples of fermented sausages. The antioxidant activity of fractions isolated from chorizo extracts was tested by their ability to quench free radicals by the DPPH-radical scavenging assay. Natural dipeptides and metabolites characteristic of meat were abundant in the fractions isolated by RP-HPLC from chorizo extracts. Due to extensive degradation during the ripening of chorizo, the extracts did not contain many peptides in a concentration that allowed identification. However, many free amino acids were identified by LC-MS/MS and HILIC-MS/MS. The fractions with the most hydrophilic compounds showed the highest antioxidant activity.