Enzymatic treatment on oil extraction and antioxidant recuperation from Oenothera biennis by cold pressing.

The aim of this work was to improve the yield in evening primrose oil extraction and the antioxidant potential of the residual meal using an enzyme assisted extraction process with cold pressing. Among four commercial enzymes, a mixture of two of them was selected in order to evaluate the effect of enzyme-substrate ratio, temperature, moisture and period of time of the enzymatic pretreatment on the extracted oil. The oil yield increased by 12% when the seeds were pretreated with 2% enzyme-substrate ratio of a mixture of 100G Ultrazym and Cellubrix (1: 1) for 15 h at 40 degrees C and 40% moisture. The defatted meal obtained from the enzyme aided process enhanced its phenol content and improved its potential antioxidant activity in comparison to the control from 250 to 276 mg of phenols/g of meal and from 1463 to 1558 mg of trolox/g of meal respectively.