DETERMINATION OF TRANS-FATTY-ACIDS IN COLD PRESSED OILS AND IN DRIED SEEDS

The adulteration of cold pressed oils (CPO) by refining or by blending with refined oils leads to an increase in their trans fatty acid (TFA ) contents. The regulations of the European Union (EU) lay down strict processing conditions without any steam treatment for native olive oi ls and provide limits for TFA. However, German regulations allow a ''s team washing'' for CPO other than native olive oil and do not limit TF A. Thus, the TFA contents of such oils might exceed the limits for nat ive olive oil. Modern capillary GLC serves as a quick tool for the det ection of TFA. However, care should be taken to avoid the formation of TFA as artefacts during analysis. We evaluated the TFA contents in se veral oils labelled as ''cold pressed'' and the formation of TFA durin g ,,steam washing'' and deodorization. Analysis of some seeds indicate s that preliminary drying of the seeds may also contribute to TFA cont ent.