Key Lipid Oxidation Products Can Be Used to Predict Sensory Quality of Fish Oils with Different Levels of EPA and DHA

Despite its many health benefits, many consumers avoid fish oil supplements due to fishy tastes and odors. Common chemical measures of oxidation have little correlation with sensory properties, making it difficult to determine the sensory quality of fish oil without the use of an expensive sensory panel. Here we investigate an alternative method to assess oxidation using solid phase microextraction and gas chromatography-mass spectrometry. Fish oils containing different amounts of eicosapentaenoic acid and docosahexaenoic acid were oxidized, and headspace volatiles were monitored over time and compared to sensory evaluations by a taste panel. Peroxide value and anisidine value were also measured. Sensory panel scores and headspace volatile data were analyzed using principal component analysis and linear regression to identify key volatiles responsible for changes in sensory degradation of oils over time. A total of eight compounds were identified, primarily aldehydes and ketones. By monitoring these volatiles, it may be possible to create a simple method to assess oxidation in fish oils that correlates well with sensory properties of the oil without the use of a sensory panel.