Blends of olive oil and sunflower oil: Characterisation and olive oil quantification using fatty acid composition and chemometric tools

► We studied blends of olive oil and sunflower oil. ► Fatty acid methyl esters analysis and chemometric tools were used. ► We differentiated blends according to the amount of olive oil contained. ► This method will be applied to other binary blends of olive oil and seed oils. A method capable of recognising the percentage of olive oil in a blend is required to verify whether its labelling complies with the statements set out by the Commission Regulation (EC) No. 1019/2002. In this study an analytical methodology was developed in order to define blends of olive oil and sunflower oil, which contain 50% of olive oil, compared to blends with 40% and 60% of it, respectively. Methyl esters of fatty acids were analysed by GC–FID and processed through chemometric tools (PCA, TFA, SIMCA and PLS). A strong differentiation of blends according to the amount of olive oil contained and a quantification model with a standard error of prediction of 1.51% were obtained. As this issue represents a significant analytical challenge, variability associated with the fatty acid composition of olive oil was first studied.