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Because of its high market value, pumpkin seed oil is occasionally adulterated by cheaper refined oils, usually sunflower oil. The standard method for detecting its authenticity is based on expensive and laborious determination of the sterol composition. Therefore, the objective of this study was to determine the sterol content and authenticity of retail oils labelled as pumpkin seed oil and also to investigate the potential of near-infrared spectroscopy (NIR) and colourimetry in detecting adulteration. The results show that due to the significant decrease in Δ7-sterols and increase in Δ5-sterols, 48% of the analysed oils can be declared as adulterated blends of pumpkin seed and sunflower oil. Significant differences in NIR spectroscopy data, in the range of 904–922 nm and 1675–1699 nm, and colourimetric data were found between the control pumpkin seed oil and sunflower oil, but only the NIR method had the potential to detect the authenticity of pumpkin seed oil, which was confirmed by principal component analysis. Orthogonal projection on latent structures (OPLS) discriminant analysis, resulted in working classification models that were able to discriminate pure and adulterated oil. OPLS models based on NIR spectra were also able to successfully predict the content of β-sitosterol and Δ7,22-stigmastadienol in the analysed oils. [ABSTRACT FROM AUTHOR]

Macro‐ and microelements in the samples of virgin and cold pressed pumpkin seed oils produced in Croatia through two consecutive crop seasons were determined by inductively coupled plasma–optical emission spectroscopy (ICP‐OES). Croatian oils were also compared to oils from Slovenia and Austria in order to assess differences in the element content. Magnesium, potassium, calcium, sodium, selenium, and iron were the dominant elements in all pumpkin seed oils. Their amounts together with barium, strontium, manganese, copper were up to ninefold higher (p ≤ 0.05) in virgin compared to cold pressed pumpkin seed oils. These differences occur due to the different processing conditions which include salt addition, heat treatment, and higher degree of equipment ware out during virgin pumpkin seed oil production. As the sodium level increases with the addition of salt, virgin pumpkin seed oil could be considered its hidden source and producers should pay attention to the amount added. Contents of cobalt, copper, selenium, and thallium significantly differed (p ≤ 0.05) between the two crop seasons. Principal component analysis revealed clear differences between samples with different origin that can be explained by the specifics in the production processes of each country. In comparison with Austrian and Slovenian, Croatian pumpkin seed oils had significantly lower contents of sodium, potassium, calcium, magnesium, and tin while bismuth and selenium were higher. [ABSTRACT FROM AUTHOR]

A group of scientists from Loeben Universtity is proposing the use of chemometrics in the detection of authenticity of Styrian PGI pumpkin seed oil. They have shown that pumpkin seeds from Austria and foreign countries differ in the composition of various element traces. Based on that they are able to differentiate between false and authentic PGI pumpkin seed using mathematical modeling. [ABSTRACT FROM AUTHOR]