Impact of Olive leaf yellowing associated virus on olive (Olea europaea L.) oil

Among the 15 virus species detected in olive trees, Olive leaf yellowingassociated virus (OLYaV) is found with high incidence and frequency inSouthern Italy in particular. Effects of OLYaV on virgin olive oil yield andquality of Leccino and Ottobratica cultivars in the Calabria region (SouthernItaly) are analyzed. Oil yield, free acidity, number of peroxides, spectrophotometricindices, total content of chlorophylls and carotenoids, total phenolcontent, composition of the fatty acids, total tocopherols, and total sterolscontent are determined on oil obtained from olive fruits collected in healthy/virus-free and OYLaV-infected trees. Almost all analyzed oil parameters arenot statistically different with some exceptions. Oils derived from ‘Ottobratica’OLYaV-infected plants have free acidity significantly lower than oil fromhealthy plants. K232 of oil from virus-free ‘Leccino’ trees is significantly lowerthan oil from infected trees. Even though some quality parameter differencesbetween healthy and OLYaV-infected oils are found, it is important tohighlight that all oils can be considered in extra virgin olive oil category,within the UE maximum limit acceptance range. Results suggest a nonegative interference by OYLaV in oil yield and quality, except for K232 values,whereas surprisingly suggest a positive effect of virus infection on free acidityparameter.Practical Applications: Based on the evidence that OYLaV does not interferenegatively in oil yield and quality parameters, it seems appropriate that theEuropean Union Council Directives (2014/96/EU, 2014/97/EU, 2014/98/EU)introduced in the last olive certification scheme only ArMV, CLRV, and SLRSV.The application of compulsory EU directive, in Italy as in other countries, willimprove the facilities of olive plants commercialization, guaranteeing enoughtheir sanitary status. The findings here reported support the suggestion thatthe Italian Ministry of Agriculture could be less restrictive in voluntary Italianregulation (D.M. 20/11/2006).