Researchers investigate reliability of virgin olive oil and pine nut authentication methods

Scientists at the University of Barcelona (UB) have presented new techniques to detect food fraud in virgin olive oil and pine nuts — two high-value products frequently mislabelled in the global market. Their research, published in Food Chemistry, offers more effective ways to verify the geographical origins of these foods, helping to protect consumers and producers from fraudulent practices.

Led by Professors Stefania Vichi and Alba Tres, the study forms part of the doctoral work of Berta Torres at UB’s Faculty of Pharmacy and Food Sciences, the Nutrition and Food Safety Research Institute (INSA), and the UB’s Torribera Food Campus. The researchers compared authentication methods to identify the most reliable tools for ensuring transparency in the food supply chain.

Tackling olive oil fraud

Virgin olive oil is a key ingredient in the Mediterranean diet, but its supply chain is particularly vulnerable to fraud. Although European regulations require producers to declare the country of origin, no official verification method currently exists. This gap allows fraudulent products to enter the market, misleading consumers and affecting prices.

To address an issue that urgently requires effective solutions, several fast, cost-effective and efficient authentication techniques have been developed and presented to identify frauds entering the market. But which method has the highest level of reliability? The UB research team’s article published in the journal Food Chemistry compares, for the first time, the two most promising methods between specific and non-specific techniques to authenticate the geographical origin of virgin olive oil: stable isotope analysis and sesquiterpene fingerprinting.

Their study, conducted in collaboration with the Research and Innovation Centre of the Fondazione Edmund Mach and the University of Perugia in Italy, found sesquiterpene fingerprinting to be the more reliable method.

The researchers stated:

The results indicated that the sesquiterpene fingerprinting method outperformed isotopic methods in reliability in several aspects, such as classification accuracy, sensitivity and selectivity.”

They also highlighted the need to increase the transferability of this technique to ensure its global application.

Uncovering fraud in the pine nut market

Pine nuts are among the most expensive nuts on the market, with Mediterranean varieties commanding much higher prices than their Asian counterparts. This price difference has led to widespread fraud, with lower-quality nuts frequently mislabelled as premium products.

In a second study by the UB team, in collaboration with the Institute of Agrifood Research and Technology (IRTA), developed an authentication method using monoterpene and sesquiterpene fingerprinting. By applying solid-phase microextraction and gas chromatography-mass spectrometry combined with chemometrics, the researchers created a fast and highly accurate detection system.

The research team concluded:

With almost no sample preparation, the methodology reveals 100 percent accuracy in distinguishing between pine nuts originating in the country and those from abroad. In addition, it reaches 99 percent in the ability to differentiate stone pine (Pinus pinea) from different regions of Spain. This powerful and automatable tool represents a breakthrough in the fight against fraud and counterfeiting in the sector.”