Study on the effect of olive fruit fly on some qualitative and quantitativecharacteristics of olive oil in different storage duration

Abstract: It has been known that the quality and quantity of the olive oil would be changed dueto the damages caused to the olive fruits especially by olive fruit fly, Bactrocera oleae. However,information on the pest infestation and its duration could facilitate achieving efficient fruitprotection measures and optimizing storage programs. Therefore, a study was conducted toinvestigate the nature and rate of variation in qualitative and quantitative characteristics of oliveoil extracted from infested fruits by olive fly at various maturing dates compared to that ofhealthy fruits. The experiment was designed in a factorial RCBC with fruit (factor A) in 2 levels(infested and healthy fruits) and maturing date (factor B) in six levels (Nov 1-19 and 2-26, Nov31 to Dec 3, Dec 4-10, 5-17). Treatments were replicated 3 times in a grove with Zard olivecultivar. The oil of a defined sample of each treatment was extracted by centrifuging their fruitfleshes separately after removing stones. The total quantity of each sample was recorded. Afterwards,they were labeled by codes and sent to the Oilseeds Laboratory, Seed and SeedlingImprovement Institute to evaluate their quality based on the Standard Olive Oil Quality Protocol.The results revealed significant differences among treatments considering some qualitativecharacteristics such as oleic acid, acidity and peroxide. In general, healthy fruits had lower acidityand peroxide but higher percent oil and oleic acid compared with those of infested fruits.However, there were not any significant differences among treatments for linoleic acid content.Therefore, it could be concluded that the damage of olive fruit fly would reduce the quality andquantity of olive oil.