Effect of cultivar and environment on chemical composition and geographical traceability of Spanish olive oils

This study aimed to investigate the influence of cultivar and environment on the chemical composition of Arbequina and Empeltre olive oils, and their contribution to geographical identification of olive oils from Aragon. A total of 260 olive oil samples from different cultivars (Arbequina, Empeltre, Royal de Calatayud, Alquezrana, and Royeta de Asque) from the three main oil-producing areas of Aragon, located in northeast Spain, were selected. Fatty acid and sterol composition were analyzed in the course of three crop years (2017, 2018, and 2019). Cultivar was found the main factor influencing the variability of palmitic, palmitoleic, and linolenic fatty acid content, whereas geographic origin was the main contributor to variation in oleic and linoleic fatty acids in Arbequina and Empeltre olive oils. Cultivar also had a significant impact on sterol composition, although the effect of the production area also showed a significant effect on these oils. Crop year showed limited relevance, except for oleic and linoleic fatty acids. The interaction between the environment (e.g., crop year and geographical factors) and the cultivar (Arbequina and Empeltre) exerted a significant influence on oleic/linoleic (O/L) ratio and Δ7-stigmastenol content, particularly in the southeast area of Aragon during the crop year with higher temperatures and drier conditions. Principal component analysis (PCA) and discriminant analysis (DA) confirmed the discriminative potential of the geographic production zone as a factor enabling the differentiation of olive oils from Aragon based on the major fatty acids and sterols.