Öz
In this study, the extraction of phenolic compounds from olive leaves by ultrasonic assisted method and the solvent type (ethanol and ethyl acetate); solvent: water concentration (90:10 (v/v), 80:20 (v/v), 70:30 (v/v)) and solid/solvent ratio (1:10, 1:15 and 1:20 (w/v)) were determined. The highest extraction yield (%), total phenolic content and antioxidant capacity values were determined for 1:20 (w/v) solids/solvent ratio and 90:10% (v/v) ethanol-water mixture. In the ultrasonic assisted extraction method; The effects of temperature, time and ultrasonic amplitude on extraction efficiency, total phenolic substance and antioxidant capacity were investigated using Box Behnken experimental design, and optimum time was determined as 5.31 min, temperature 39.27ºC and amplitude 40.51%.Then, the oleuropein-rich extract was encapsulated using the ionic gelation method, and the effects of extract concentration, chitosan concentration and waiting time on the encapsulation efficiency and total phenolic content were optimized using CCRD experimental design. In the encapsulation process, the optimum conditions were determined as 1.04%, the extract concentration; 0.5%, the chitosan concentration and 11.24 min, the waiting time. In addition, it was determined that microcapsules added to kefir produced for functional food did not show an inhibitory effect on LAB bacteria and suppressed the bitter taste and aroma of the extract.