Sensory impact of lipid oxidation in complex food systems

In this review of the sensory impact of lipid oxidation, off-flavours caused by lipid oxidation in various complex food products are summarised. Further, it is demonstrated that sensory data often do not correlate well with data obtained by simple chemical analytical methods, such as peroxide values and anisidine values. It is also demonstrated that even if chemical oxidation data indicate that different food products are oxidised to the same degree, the sensory impact of lipid oxidation may be very different in various foods. Based on these data coupled with determinations of the oil-water partition coefficients of selected volatile oxidation products in fish oil enriched mayonnaise a hypothesis was recently suggested to explain these differences. According to this hypothesis oxidation products present in the aqueous phase of mayonnaise will have a major impact on the sensory perception of oil-in-water emulsions like mayonnaise. Finally, data from our recent investigations in which sensory analysis was employed together with electron spin resonance, GC-MS, HPLC and measurements of the rheological properties and physical structure of mayonnaise are discussed. These methods were used to study the effect of various antioxidants of commercial interest in fish oil enriched mayonnaise. A major conclusion from these studies is that GC-MS data correlate well with sensory data, but that more research is necessary to clarify the sensory impact of both individual lipid oxidation compounds and combinations of these products in complex food emulsions.