Bouillon cubes: assessment of the state of degradation of the lipid fraction

An experimental investigation was carried out to assess the oxidative and hydrolytic quality of the lipid fraction of bouillon cubes. Besides the routine analyses prescribed by EC regulations, determinations of fatty acid composition and unsaturated fatty acid trans isomers were also performed. From the lipid fraction extracted from each cube, polar compounds were separated by silica gel column chromatography and then submitted to HPSEC (high-performance size exclusion chromatography) analysis to determine the classes of substances deriving from oxidation, polymerisation and hydrolysis of triglycerides. The data obtained showed that the determination of trans isomers and the subsequent HPSEC analysis of polar compounds enable one to ascertain the actual degradation of the lipid fraction of such food preparations. The degree of degradation of the lipid fraction of bouillon cubes was similar to that normally found in olive-pomace oil, which is the poorest olive oil commercial class. Finally, the contents of trans isomers and triglyceride oligopolymers are shown to be significantly higher in hydrogenated than in non-hydrogenated vegetable fats.