Influence of Olive Storage and Processing on Some Characteristics of Olive Oil
Desanka Rade, Dubravka Štrucelj, Ž. Mokrovčak and Z. Hrboka
Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
Received September 22, 1994
Accepted June 19, 1995
Sonic properties and quality of olive oil obtained by pressing and by centrifugal extraction from fruits of blended varieties of olives (about 30-40 % of Oblica and about 60-70 % of Drobnica) and Laslovka variety were examined. Because of unfoward circumstances the olive fruits were kept until processing in sea or tap water. The content of free fatty acids, peroxide value, unsaponifiable matter, chlorophyll, absorbnnces in the UV range and intensity of bitterness were determined in oils. Keeping the fruits in the water (especially in sea water) from the time of harvest to the time of processing, has proved to be a fairly good method of olive storage, because in the oil samples kepi in this way for several months no significant hydrolytical or oxidative changes occurred. Olive oils obtained by the technological process of continuous centrifugal extraction have a higher content of chlorophyll and bitter substances than the olive oils obtained by pressing. The oil obtained from the olives of Laslovka variety had a particularly high intensity of bitterness.
Presented at the 2nd Croatian Congress of Food Technologists, Biotechnologists and Nutritionists, Zagreb, June15-17,1994