Quality Control of Olive Oils in EEC: Origins, Evolution and Recent Trends

Lanfranco Conte, Olivera Koprivnjak

Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, Via Marangoni 97, 33100 Udine, Italy

Article history:
Received July 25, 1996 
Accepted December 18, 1996

Key words:
olive oils, quality control, analytical methods, EEC, COI

Summary:
Oils obtained from olives represent a very important field of the agro-food industry and economy of the Mediterranean countries of the EEC. Until September 1991, every country had national laws and national official methods of analysis. Starting from September 1991, EEC published a regulation (No 2568), tliat by its nature superseded the national laws. The composition of fatty acids and sterols, with respect to genuineness, is analyzed by capillary gas chromatography, so that ample information can be obtained by one analysis: in the sterol fraction, up to 16 compounds can be observed, against the reduced numer separated by packed column GLC. If the determination of fatty acid composition is carried out by capillary GLC, the presence of trans isomers above 0.05% in a virgin oil can be detected, thus revealing its being mixed with refined oil. If sterols are destroyed in seed oils so that they can be mixed with virgin olive oils, dehydration products of sterols, named sterenes, are formed: the new EEC regulation No 656, published in March 1995, introduced the determination of stigmastadienes. COI has also included the determination of ratios between the dehydration products of single sterols, with the aim of detecting the mixture of seed oils in refined olive oils. Waxes, too, are determined, as their high value is a consequence of mixing with olive pomace oil. Among the analytical parameters, for the first time sensory analysis has been used by law: a panel test is one of the parameters prescribed by the EEC. COI is developing a new method based upon continuous scales.