Volatile terpene fingerprinting for pine nut authentication

Abstract

[eng] Pine nuts are highly valued products on the market, with 20 species being the most commercially significant both globally and locally. Among these, Mediterranean pine nuts (Pinus pinea) are the most highly valuated, reaching prices up to 100€/Kg, in contrast with other species sold at much lower prices (Chinese and Russian pine nuts). The high prices added to the lack of fast and low-cost analytical methods to assess the authenticity in routine analysis make pine nuts highly vulnerable to fraudulent practices. This study proposes a reliable method for pine nuts geographical and botanical origin authentication. The volatile and semi-volatile terpene hydrocarbon fingerprint of a set of 245 pine nuts from different origins (Spain, China, and Russia) and different species was analysed by HS-SPME-GC-MS. PLS-DA models were built to differentiate between Iberian and non-Iberian samples and between production regions on Pinus pinea samples, with satisfactory clustering on all categories based on their respective PLS-DA score plots. Both models were internally and externally validated, achieving correct classification values of 100% and over 96% respectively, ensuring that model predictions are reliable. Hence, this method has proved to be a suitable option for pine nut authentication on industry routine analysis supporting official controls.