The production of olive leaf extrtact loaded nanophytosomes and determination of their storage stability

Objective: The aim of the thesis is to produce olive leaf extract nanophytosome by thin layer hydration method. Materials and Methods: Olive leaf extract nanophytosome was produced by different phosphatidyl choline and extract ratios, sonication power and times present in D-optimal combined design experimental design. Processing conditions were optimized so that the particle size is minimum and the encapsulation efficiency is maximum. Olive leaf extract nanophytosome manufactured with optimal conditions was evaluated in terms of polydispersity index, zeta potential, morphological structure, FTIR spectrum and storage stability at 4 and 25 °C. Results: The findings revealed that the particle size decreased as the olive leaf extract ratio in nanophytosomal structure increased. Optimum conditions for olive leaf extract nanophytosome production were determined as 79.75 mg phosphatidyl choline, 20.25 mg olive leaf extract with 379 W sonication power and 10.5 min sonication time. The polydispersity index of the nanophytosome produced under optimum conditions was determined as 0.24, and the zeta potential was determined as -19.05 mV. While SEM images showed that nanophytosomal structures were in spherical structure, FTIR spectra revealed that hydrogen bonds formed between O-H groups of olive leaf extract and polar groups of phospholipid, thus phytosome structure was formed. While the particle size remained constant for 28 days in storage at 4 °C, it increased in storage at 25 °C. There was no significant difference in zeta potential and polydispersity index at both temperatures. The antioxidant activity of the olive leaf extract encapsulated with the nanophytosome structure was found to be higher than the unencapsulated form. Antioxidant activity decreased with storage in both forms. Conclusion: In this study, olive leaf extract nanophytosome production was optimized; it has been found that nanophytosomal structures produced under optimum conditions have higher storage stability compared to the unencapsulated extract. Keywords: Encapsulation efficiency, nanophytosome, particle size, stability, olive leaf extract