The olive stone water extract obtainment by using pressurized water extractor at pilot scale and its microencapsulation

In this thesis project, the aims were, to obtain extract which is full of phenolic compounds from olive stones that are disposed by olive and olive oil industries using pressurized water extractor at pilot scale and to encapsulate this extract by the help of spray drying method on the purpose of producing anti-oxidant food additive which comes from a naturel origin. Thus, the product classified "waste" would be redounded on economy and on the other hand, it could be an alternative for synthetic additives. In consequence of storing encapsulated product at different temperatures (-20ºC, 4ºC and 25ºC) for 6 months, choosing the best storing temperature and determining the changes dependent on degradation occurred in encapsulated product during storage were targeted. As raw material, "Domat" type olive stones supplied from Akhisar, Manisa were used. Firstly, the contents of olive stones were determined, and then water extract was attained through the system of pressurized water extraction. Extraction conditions like temperature, pressure and time were optimized in order to get extract which is rich in phenolic compounds. Water extract produced at optimum conditions (50ºC, 50 bar, 90 min) was microencapsulated using 1% chitosan solution. In spray drying technique, three different inlet and outlet air temperatures (160ºC/78ºC, 180ºC/90ºC and 200ºC/94ºC) were studied. High air temperature made achieving product that has high rate of phenolic compounds. Also the moisture content of new product was relatively low. The physical characterization of microcapsules acquired at 200ºC inlet and 94ºC outlet temperature was specified by making out their particle, bulk and reconstitution properties. Polyphenol oscillations, phenolic compounds and anti-oxidant effects of extract and microencapsulated product were determined in vitro gastrointestinal system condition. Stabilities of microcapsules and polyphenol, anti-oxidant properties of microencapsulated product were evaluated by means of monthly analysis during storage at different temperatures. Water activities and colour values of microencapsulated product were examined and phenolic compounds were described by HPLC technique qualitatively and quantitatively at 0th and 6th month. Phenolic compounds and anti-oxidant effects had good levels at 4ºC storage temperature and the degradation rate of related components was relatively high at -20ºC. Coefficients belonged to degradation kinetic were also computed. As a consequence, extraction study at pilot scale performed for one of the important wastes, "olive stone" is attracted notice because of that it could be adapted into industry. Also this research can play a significant role because of making enable to use olive stone containing various phenolic consitituents as a natural anti-oxidant.