Slovenia maintains two olive collection orchards planted with varieties selected in the local area on the basis of morphological description. They are both of vital importance for the maintenance of the national olive gene bank. Given the fact that some trees have decayed and new stock has been planted, some planting places are inappropriately marked. In order to prevent inappropriate evaluation of varieties thriving in the collection orchard in Strunjan, we used microsatellite markers to check all planting places and their identification labels. The analysis involved 100 trees belonging to 27 olive varieties. In order to obtain reference profiles of the individual varieties, we used microsatellite loci selected on the basis of our previous experience and published scientific articles (DCA-09, DCA-16, DCA-03, DCA-11, UDO-99, EMO-03, GAPU-101). The identity of trees within the individual varieties was established in 17 varieties. Inappropriate identification of the planting stock was discovered in the variety 'Buga'. Microsatellites revealed that the fifth tree of this variety in fact belongs to the variety called 'Belica Pucer'. The classification of varieties into related groups was done by using the UPGMA method, and the dendrogram shows that the varieties are divided into two large groups. The first group is very heterogeneous from the point of view of geographical origin, and it includes a small independent subgroup of olive varieties with big fruits. The second group consists of varieties from central Italy. Microsatellites proved to be a very useful tool for unambiguous identification of olive varieties and collective orchard inspection and management.
COBISS.SI-ID: 2175955
The article deals with characterization of sterols in olive oil. Sterols are an important unsoapable component of vegetable fats. Vegetable oils contain 15 sterol components. With individual types of oil being characterized by different sterol components, sterol composition and content are important parameters in the determination of olive oil authenticity since deviation from values stipulated by the Commission Regulation (EEC) No 2568/91 can indicate that another vegetable oil has been added to the olive oil sample. The analysis of sterol composition can helps us determine whether less than 2% of soya oil, 1% of sunflower oil or 0.5% of rape oil has been added to olive oil, while a total sterol content lower than 1000 mg/kg oil indicates addition of desterolized oil. Soya oil is characterized by a high content of stigmasterol (16−19%), sunflower oil by a high content of 7-stigmastenol (10−20%), rape oil by a high content of brassicasterol (5−13%) and olive oil by a high content of β-sitosterol (65−88%). In addition to β-sitosterol, olive oil contains -5-avenasterol, clerosterol, campesterol, campestanol, -7-campesterol, stigmasterol, -5,23-stigmastadienol, 24-metilencholesterol, -7-stigmastenol, -7-avenasterol, brassicasterol, cholesterol, -7,22-ergastadienol, -7,24-ergostadienol, and 22,23-dihydrobrassicasterol. With the contents of the afore-mentioned sterols depending on the variety, we discovered very big differences in -5-avenasterol contents between oils from 'Istrska Belica' and oils from other varieties. The data collected is of high importance for the characterization of the Slovene olive oil as no differences between oils from different years were detected.
COBISS.SI-ID: 2176467