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13443907282?profile=RESIZE_400xA key advantage of the Direct Analysis in Real Time (DART) mass spectrometry (MS) ion source is its ability to ionise the sample without the need for extraction.  In this study (open access), the authors compared DART with a previously-published extraction-based MS method to analyse key components in olive oil.

Having optimised and validated DART-MS, they then used it to build a discrimination model between different classes of edible oils.  They analysed a reference set of 80 samples from different regions of Greece (Crete, Peloponnese, Central Greece, and the North Aegean) to discriminate authentic extra virgin olive oil (EVOO).  These were from 10 oil categories including 35 EVOOs, 15 lower-quality olive oils (five of each category: refined, olive pomace, and ordinary), and 30 vegetable oils (five of each type: sunflower, corn, soybean, canola, sesame, and linseed).

They report that multivariate statistical analysis revealed clear discrimination of EVOO from other oils and enabled detection of EVOO adulteration down to 1 % with vegetable oils and 5 % with lower-quality olive oils. Key authenticity markers, including phenols, squalene, and triacylglycerols (TAGs), were identified.

They conclude that the proposed method demonstrates high potential for rapid, reliable EVOO authentication in routine quality control.

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13709264077?profile=RESIZE_400xCold-pressed fruit seed oils from blackcurrant, raspberry, and strawberry are gaining market share and – as relatively high value oils – are potential targets for adulteration. This study (open access) used identified 28 triacylglycerides (TAGs) as significant markers for distinguishing the 3 oils.  These were identified from chemometric analysis of full tryglyceride profiles.  Triglycerides were measured by ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. Lipidomic analysis identified 215 glycerides in the three oils. Chemometric analysis revealed that TAG profiles were superior to diacetylglyceride (DAG) profiles for oil differentiation and detecting adulteration. OPLS-DA identified 28 TAGs as significant markers for distinguishing the three oils.

The authors reported that comparison of glyceride profiles of pure and adulterated samples demonstrated that adulteration with 5 % or more sunflower or rapeseed oil could be detected. Targeted metabolomic analysis using specific markers for sunflower oil confirmed adulteration in raspberry and strawberry commercially purchased fruit seed oils.

Photo by Stan Slade on Unsplash

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