DIACYLGLYCEROLS IN THE EVALUATION OF VIRGIN OLIVE OIL QUALITY

Virgin olive oil samples were analyzed within one month after extraction and after one year; edible and lampante olive oil samples were analyzed before and after neutralization of free acids. In addition to the usual quality parameters, the amount and position isomers of diglycerides were equally assessed. It was found that extra virgin olive oils, even through analyzed after one year, still meet al least two of the following five requirements: a) total diglycerides less than or equal to 2.0%; b) 1,2-diglycerides less than or equal to 1.5%; c) 1,3-diglycerides less than or equal to 0,4%; d) total diglycerides x 1,3-diglycerides less than or equal to 1.0; e) total diglycerides/1,3-diglycerides > 5.0. It is therefore suggested that for extra virgin oils to be defined, they should comply with at least two of the above parameters, in addition to the characters prescribed for by EC Regulations Nos. 2568/91 and 183/93.