Influence of extraction system, production year and area on Cornicabra virgin olive oil: a study of five crop seasons

This paper describes a study of the influence of the extraction system, crop season and production area on the chemical composition and quality of Cornicabra virgin olive oils (n=152) from five successive crop seasons (from 1994/1995 to 1998/1999). Analysis of the effect of the extraction system (dual-phase, triple-phase decanters and pressure) on the values of analytical determinations, revealed statistically significant differences (P⩽0.05) in a few parameters only, mainly in antioxidant content (total phenols and α-tocopherol) and oxidative stability. All quality indices and major fatty acid and sterol compositions presented significant statistical differences (P⩽0.001) with respect to the year of production, with the exception of total phenols. The crop season is therefore a critical variable, since the chemical composition of the olive oil may vary considerably from one year to the next. Many of the analytical parameters varied among the five production areas considered, in the provinces of Toledo and Ciudad Real. The results appear to confirm the general consensus on the quality of Cornicabra virgin olive oils from Castilla-La Mancha, namely that oils from mills located in the south and southeast of the province of Toledo are generally of higher quality.