MONITORING THE RESIDUAL ACTIVITY OF ROTENONE IN ORGANIC OLIVE OIL

Olive trees cv “Koroneiki” located in the Nerokorou district of Chania, Crete received a single spray treatment of 10% or 20% of active Rotenone respectively. Fruits of treated olive trees were evaluated for Rotenone residues before and at the end of harvest, while the final olive oil extracted was evaluated during storage for 8 months. The rate of Rotenone degradation was linear and fast in both treatments in the field taking into account the concentration sprayed. Post harvest monitoring of the final oil in storage under dark, freezing temperature and light (at room temperature) between December 1996 and August 1997 shows that light and temperature play dominant roles in Rotenone degradation in stored olive oil. In both dark and refrigerated oil samples Rotenone residues were relatively stable and the rate of degradation was very slow. However, the oil sample transferred to light after 5 months storage (May, 1997) reveals a 39% decline in Rotenone content in the first 2 months under light (7 months after the initial storage time) and a slight decrease in the following month.