Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
The composition of olive oil volatile components depends on genetic factors, ripening grade of the fruit, fruit storage and processing conditions. Storage of olives in reticular or plastic bags is still a frequently used practice that has negative effects on oil quality, particularly on sensory characteristics. The changes of volatile compounds during this procedure were determined using headspace solid phase microextraction (HS-SPME). The method was optimised as regards sample conditioning and extraction time, and verified by testing the repeatability and linearity of the response. The main changes during fruit storage in bags are increase of methanol and ethanol concentration and decrease of 1-penten-3-one, trans-2-hexenal and cis-3-hexenyl acetate concentration. The changes in plastic bags are more evident and significant differences between the two types of storage are established.Sastav hlapljivih sastojaka maslinovog ulja ovisi o genetičkim faktorima, stupnju zrelosti plodova i njihovu skladištenju te uvjetima preradbe. Još uvijek se često primjenjuje skladištenje maslina u mrežastim ili plastičnim vrećama, što negativno utječe na kakvoću ulja, osobito na senzorska svojstva. Promjene hlapljivih sastojaka tijekom ovoga postupka utvrđene su primjenom mikroekstrakcije na čvrstoj fazi u natprostoru (HS-SPME). Metoda je optimirana s obzirom na kondicioniranje uzorka i vrijeme ekstrakcije, te provjerena utvrđivanjem ponovljivosti i linearnosti odgovora. Glavne su promjene tijekom skladištenja plodova u vrećama povećanje koncentracije metanola i etanola, te smanjenje koncentracije 1-penten-3-ona, trans-2-heksenala te cis-3-heksenil acetata. Promjene u plastičnim vrećama više su izražene, a uočene su i bitne razlike između dvaju načina skladištenja
