Membranes were used in many aqueous applications, including in food processing, e.g. clarification of fruit juices. Typical drawbacks of membrane processes are membrane fouling which promotes deterioration of process products. During application of membranes for fruit juice clarification, biofouling occured as the process deals with food subtances. Biofouling is commonly dominated by bacterial attachment and growth on membrane surface, following the deposition of organic molecules from food substances. Natural antibiotics such as Olea europaea leaves extract might be used to improve the antibiofouling properties of membranes due to its phenolic contents. In this work, Olea europaea substances were obtained by extraction to get the green active solid nanoparticles. Phenolic green nanoparticles then impregnated into cellulose acetate polymer to form mixed matrix membranes with higher and safe (foodgrade) antibiofouling properties. The anti-bioulant effect has been proven by decreasing bacterial attachment down to 23% from initial condition, especially for Gram-negative bacteria such as Eschericia coli.