A study of changes in the fat content of some varieties of dry sausage during the curing process

The influence of the curing of dry sausage (chorizo, saucisson, salami) on the chemical composition of lipids was studied in terms of what affects the oxidation and resulting production of volatile aldehydes, mainly hexanal. Microbial fermentation initially increases the unsaturation, although this phenomenon is reversed during the drying-curing process. In this phase the saturation/unsaturation ratio rises in C16 and C18 fatty acids, the increase being higher in chorizo and lower in salami. Stearic acid appears to increase more than palmitic acid, and C16 quotient values show significant differences across a range of commercially-sold brands of each type of sausage. Unsaturation varies in parallel with the iodine value in the three cases studied. Lipolytic phenomena produce fatty acids with a greater amount of linoleic acid than oleic acid. The oxidation of these fatty acids is progressive regardless of whether TBA or carbonyl values are measured. Nevertheless, significant correlations of hexanal concentrations are not evident. The formation of butanal and pentanal (<2 μmol) is very low, and hexanal concentration fluctuates (11-111 μmol) among commercial brands and types of sausage. These concentrations are always much higher in chorizo samples than in those of salami. Statistical multivariant analysis highlights the greater significant differences in salami samples, a sausage which reflects the lack of homogeneity between different industrial processes.