Caratterizzazione chimica di oli di oliva raffinati e di prodotti di seconda lavorazione (repaso) offerti sui mercati nazionale e internazionale

In this work, quality (free acidity, peroxide and alkyl esters) and composition (long-chain aliphatic aldehydes) parameters were evaluated on 15 oil samples from olive processing, obtained from the international market. The samples were 3 genuine extra virgin olive oil samples of known origin, 2 lampante olive oils and 2 corresponding refined samples, 4 oils produced from second-olive processing (repaso) and other 4 refined olive oils. Alkyl esters were not found in either extra virgin olive oils or refined samples, whereas their content was high in lampant (63-607 mg/kg) and in repaso (416-1597 mg/kg) oils. Squalene was abundant in extra virgin olive oils, while its content decreased in repaso oils and was very low in refined samples. Finally, a higher content of long-chain aliphatic aldehydes was detected in lampante and repaso oils. These preliminary findings will be confirmed by the analysis of a larger set of samples taking into account lampante oils from different geographical proveniences (i.e. Italy and other Mediterranean countries) as well as samples undergoing different refining conditions.