Acidic and enzymatic pre-treatment effects on cold-pressed pumpkin, terebinth and flaxseed oils

Oil yield and the properties of oil can be improved with various enzymatic pre-treatments before obtaining oil from oilseeds by cold-press extraction. A commercial mixture of pectolytic enzymes was used in this study. In addition, apple seed meal as a source of β-glucosidase enzyme and citric acid were applied to oilseeds (pumpkin, terebinth and flaxseed) as pre-treatments. The results were evaluated by comparing the effects of the pre-treatments on oil yield and properties. Enzyme preparate could increase the oil yield of pumpkin seeds (~300%) and flaxseed (151%). Significant increases in the phenolic contents of terebinth (from 91.67 to 319.33 mg GAE/kg) and flaxseed oils (from 12.03 to 40.47 mg GAE/kg) were achieved by citric acid and enzymatic pre-treatments. These two pre-treatments were also effective in terms of peroxide formation and oxidative stability in terebinth oil. With the help of the pre-treatments applied to oilseeds it was possible to increase the transition of phenolics from seeds to oil for terebinth oil with increase ratios of 245% for citric acid, 248% for the enzymatic process compared to the control.