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Proteomic analysis of wild boar meat: Effect of storage method and time on muscle protein stability
LC–MS Metabolomic Profiling of Five Types of Unrefined, Cold-Pressed Seed Oils to Identify Markers to Determine Oil Authenticity and to Test for Oil Adulteration
The authenticity of food products marketed as health-promoting foods—especially unrefined, cold-pressed seed oils—should be controlled to ensure their quality and safeguard consumers and patients. Metabolomic profiling using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC–QTOF) was employed to identify authenticity markers for five types of unrefined, cold-pressed seed oils: black seed oil (Nigella sativa L.), pumpkin seed oil (Cucurbita pepo L.), evening primrose oil (Oenothera biennis L.), hemp oil (Cannabis sativa L.) and milk thistle oil (Silybum marianum). Of the 36 oil-specific markers detected, 10 were established for black seed oil, 8 for evening primrose seed oil, 7 for hemp seed oil, 4 for milk thistle seed oil and 7 for pumpkin seed oil. In addition, the influence of matrix variability on the oil-specific metabolic markers was examined by studying binary oil mixtures containing varying volume percentages of each tested oil and each of three potential adulterants: sunflower, rapeseed and sesame oil. The presence of oil-specific markers was confirmed in 7 commercial oil mix products. The identified 36 oil-specific metabolic markers proved useful for confirming the authenticity of the five target seed oils. The ability to detect adulterations of these oils with sunflower, rapeseed and sesame oil was demonstrated.
Heat-stable peptide markers specific to rabbit and chicken liver tissue for meat product authentication testing
Identification of sunflower, rapeseed, flaxseed and sesame seed oil metabolomic markers as a potential tool for oil authentication and detecting adulterations
Testing the composition, quality and authenticity of edible oils is crucial to safeguard the consumers’ rights and health. The aim of our study was to identify oil-specific markers to enable the differentiation and authentication of sunflower, sesame, flaxseed and rapeseed oils, and to evaluate their antioxidant activity, total phenolic and carotenoid content. A metabolomic approach based on liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry was employed for marker discovery. Spectrophotometric method was used for determination of antioxidant activity, total phenolic and carotenoid content. 76 oil samples from the four different manufacturers were examined. We identified 13 oil-specific markers for sunflower seed oil, 8 for rapeseed oil, 5 for sesame seed oil and 3 for flaxseed oil, their retention times, accurate masses, and characteristic fragment ions are reported. The abundances of the markers for each plant species were found to vary depending on the oil producer and the product batch. Significant differences in antioxidant activity, total phenolic and carotenoid content were also observed both between oils and within oil type. The highest total phenolic content (84.03 ± 4.19 to 103.79 ± 3.67 mg of gallic acid/kg) and antioxidant activity (245.67 ± 7.59 to 297.22 ± 2.32 mg Trolox/kg) were found in sesame seed and flaxseed oils, respectively. Identified metabolic markers can be used as qualitative markers to confirm the authenticity or to detect adulterations of oils. Composition, properties and authenticity testing should be more rigorous for food products marketed as health-promoting.