Algorithms for the detection of hazelnut oil in olive oil

Abstract

The fraudulent addition of hazelnut oil to olive oil can be only detected in high proportions (20–25%), using the D7-stigmastenol and the difference between triacylglycerols of equivalent carbon number 42, determined experimentally by HPLC and calculated theoretically from the fatty acid composition (DECN42). A new method lies on a sequential comparison of the values of several algorithms with a database built with data obtained from genuine virgin olive oils. The algorithms are: LLLexp vs %L; (LLL/OLLn)exp - (LLL/OLLn)theor vs DECN44 and (ECN44/LLL)exp vs %L; being LLLexp, OLLnexp, and ECN44exp the percentage of triacylglycerols determined by HPLC; LLLtheor, OLLntheor, and ECN44theor the percentage of those calculated theoretically from the fatty acid composition; DECN44 the difference between the experimental and theoretical value of ECN44; and finally %L the percentage of linoleic acid. The database has been built considering the values obtained from olive oils of different fatty acid composition and from admixtures between them. The method allows the detection of low percentages of hazelnut oil in olive oil (5 %).

Keywords

• ecn42
• ecn44
• fatty acid methyl esters
• hazelnut oil
• olive oil
• triacylglycerol