Microencapsulation of bioactive substances from biowaste and their release behavior in various foods

This thesis is a study that aims to recover added high value-added substances from biomass with environmentally friendly methods. For this purpose, the selected raw materials (olive leaves, hibiscus, rosehip seed, plum peel and sour cherry peel) were first extracted with aqueous alcohol solution using the Automatic Solvent Extraction (ASE) system, which is also an advanced extraction system. Microencapsulation process was applied to the extracts rich in bioactive components by ionic gelation and spray drying methods, respectively. Response Surface Methodology (RSM), a statistical design method, was used for microencapsulation. In this way, optimum conditions were determined, the systems were modeled, and the effect of each parameter on the systems was determined. While optimizing, the target was dependent variables such as the highest encapsulation efficiency (EE), the highest encapsulation yield (EY) and the highest bioactive properties (such as phenolic compounds, anthocyanins and antioxidant activity). Depending on the encapsulation method used, wall material ratio, wall material concentration, time and temperature were selected as independent variables. Dependent and independent variable selections and levels were determined by taking into account previous studies and preliminary trials. Additionally, various morphological (particle size distrubution and particle shape) and physicochemical properties (moisture content, water activity, solubility, bulk density, tapped bulk density and Carr index) of microcapsule samples obtained under optimum conditions were also determined. The same samples were subjected to in vitro release studies to determine the bioavailability of the relevant bioactives. Finally, the particles were applied as food additives to the 2 most consumed model food products (sunflower oil and corn oil) in order to increase the functional properties of foods. Improvements in food products were evaluated in terms of resistance to oxidation, phenolic substances and antioxidant activity. Keywords: Food safety, biorefinery, natural additives, functional foods, multivariate optimization