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In this study (open access) researchers developed and validated new new polymerase chain reaction (PCR) systems for detection of rapeseed in small samples of highly processed vegetable oils oils.

They designed primerss targeting the rapeseed acetyl-CoA carboxylase (ACCase; BnACCg8) gene, and optimised the PCR conditions after genomic DNA extraction from ground seeds and 700 µL aliquots of edible oils. DNA was isolated using two commercial kits, and PCR products were assessed by agarose gel electrophoresis.

They report that Uniplex PCRs demonstrated species specificity, producing 147-bp and 174-bp amplicons only in rapeseed DNA, with no amplification in soybean, sunflower, or maize. PCR bands from oils were weak or absent but implementing a double-PCR approach increased detection sensitivity in oils by approximately fivefold. Strong, expected-size amplicons were obtained from all oil extracts, confirming reliable detection of rapeseed in both cold-pressed and refined varieties, regardless of extraction method.

They conclude that this approach offers a sensitive, rapeseed-specific molecular tool for verifying the botanical origin of edible oils. It is suitable for routine authenticity testing and quality control of vegetable oils.

Low Field (LF) Nuclear Magnetic Resonance (NMR) spectrometers have been used for routine inline quality control in the processed meat industry for many years.   Recent advancements have made the technology more accessible for other applications.

This proof-of-concept study (open access) demonstrates the potential of LF NMR for rapid oil authentication in an industrial setting. Their approach was based on solvent-free oil analysis using a single scan ¹H NMR measurement on a LF 80 MHz NMR instrument. The analysis identified the allylic signals at δ 2.0 ppm as a potential diagnostic region, effective in detecting adulteration in the oil samples. They limited the integration to this one spectral region in order to make data analysis rapid and easy to use in a food factory.

The authors demonstrated successful detection of adulteration in two types of vegetable oils rich in polyunsaturated fatty acids (PUFA), rapeseed and sunflower oil, at levels ranging from 5 % to 25 %. Specifically, the study found that adulteration in rapeseed oil could be detected at levels as low as 5 % when adulterated with soybean oil, 10 % when adulterated with sesame and cottonseed oils, and 25 % for corn oil and safflower oil. In the case of sunflower oil, cottonseed oil can be identified at 5 % adulteration, while corn, sesame, and safflower oils can be detected at 25 % adulteration.

The authors consider that the approach is fast, user-friendly, and ecological.  LF NMR could be a valuable tool for identifying adulteration in edible oils, with applications in various industries. This method would benefit from further research to validate the allylic region as a diagnostic region of oil adulteration.

Photo by Fulvio Ciccolo on Unsplash