(446f) Purification of Olive Leaf Extract Via Polycarboxyl Ester Resin

In this study, olive tree (Olea europaea) leaf was selected as the potential antioxidant source rich in phenolic antioxidants such as oleuropeosides including oleuropein and verbascoside, flavonoids including luteolin, luteolin-7-O-glucoside, apigenin-7-O-glucoside, diosmetin-7-O-glucoside, diosmetin, rutin and catechin, and simple phenolics including tyrosol, hydroxytyrosol, vanillin, vanillic acid and caffeic acid. Oleuropein is the chief constituent of the olive leaf extract, which is mostly responsible for the antioxidative, antimicrobial, antiviral, antiatherogenic, and cardioprotective, antihypertensive and anti-inflammatory properties. For this reason, it is a great value of seperating these plant extracts rich in phenolic compounds and using them as antioxidants in food, pharmaceutic and cosmetic industries. Purification after extracting the plant material might be essential to obtain extracts rich in phenolic content due to the many other compounds such as sugars, protein or metals in the plant extracts.

Generally, phenolic contents of natural extracts are purified by adsorption-desorption processes by polymeric adsorbents. Polymeric macroporous resins are commonly applied as purification matrices in food industry owing to their high efficiency, low pollution and procedural simplicity. This study aims to investigate the static adsorption of phenolics in olive leaf on several macroporous resins. Adsorption kinetics and thermodynamics of the resin XAD 7HP were investigated by means of static adsorption and desorption tests. At every step of the open batch procedure, the efficacy of the purification was assessed by the determination of total phenolic content and the major phenolic compound, oleuropein. Taking into account of ecological and dietary restraints, generally recognized as safe (GRAS), ethanol solution was used as solvent agent in the extraction process.