Effects of olive scale (Parlatoria oleae (Colvée)) attack on yield, quality and fatty acid profile of virgin olive oil

Olive scale (Parlatoria oleae (Colvée)) is a common pest in Mediterranean olive orchards which primarily causes damage on olive fruits. The quality of virgin olive oil is strongly related to the health status of the olive fruits from which is extracted. In this paper the effects of olive scale (Parlatoria oleae (Colvée)) attack on the oil yield, chemical and sensorial quality, as well as on the fatty acid profile of virgin olive oil were studied. Olive fruits (Olea europea L.) from Bova cultivar (Istria, Croatia) were collected and divided into different groups according to the presence or absence of infestation by the olive scale. Olive scale attack did not induce ripening process nor stimulate oil synthesis in the infested fruits. Healthy and infested fruit groups were processed separately to produce corresponding olive oils. As regards the oil acidity, the oil samples obtained from infested fruits had similar values as samples obtained from healthy fruits. However, olive scale attack led to slight oxidative deterioration of oil, but had no effect on sensory characteristics of obtained olive oils. Fatty acid profile was slightly affected by olive scale attack: an increase of linoleic (about 13 %) and palmitoleic acid (about 8 %), but a decrease of oleic (about 3 %) and stearic acid (about 4 %) in oils obtained from infested fruits was detected. Oleic to linoleic ratio was lower in oils obtained from infested fruits indicating its lower oxidative stability.