Determination of (E)-5-methylhept-2-en-4-one in deodorised hazelnut oil. Application to the detection of adulterated olive oils

The presence of (E)-5-methylhept-2-en-4-one (filbertone) in a hazelnut oil, deodorised in a laboratory system using nitrogen as stripping gas, is studied regarding its usefulness as a chiral marker for detecting adulterations of olive oil. The analytical method involves the use of both simultaneous distillation–solvent extraction as a sample concentration step and a chiral stationary phase in the subsequent gas chromatographic analysis. The procedure is simple, rapid, effective for detecting adulterations of olive oil with hazelnut oil and can reduce falsely negative results obtained if conventional parameters included in current regulations are exclusively considered when establishing purity in olive oils.