Physico-chemical properties, tocopherol contents, fatty acid composition and phenolic compounds of olive oil as affected by papain and cellulase application

The effect of the cellulase and papain enzymes treatments, at the malaxation stage before cold pressing from Ayvalık, Gemlik, Yağlık and Çöpaşı olives, were evaluated in relation to free fatty acid, peroxide value, oil yield, color values, tocopherol content, fatty acid composition and phenolic components in the obtained oil samples. According to the results, it was observed that enzyme usage and application time caused significant differences on free fatty acid (p < 0.05) and peroxide value (p < 0.01). The highest free acidity (8.57%) and peroxide value (12.00 meq O2/kg) were detected in oils from Ayvalık (12 h-papain 1.0% (w/v) treatment) and Çöpaşı (24 h-papain 1.0% (w/v) treatment), respectively. Tocopherol contents, fatty acid composition and phenolic components showed increase in 12 h treated samples. The oil samples obtained after 12 h cellulose 1.0%(w/v) treatment showed the highest (254.7 mg/kg) tocopherol content. Oleic acid contents of oil samples varied between 63.36 and 72.68%. Hydroxytyrosol and tyrosol contents were higher in the samples with low oleuropein content. Generally, cellulose 1.0% (w/v) application resulted in better nutritional quality of the oils.