Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Development of Bioactive-Loaded Hollow Solid Lipid Micro- and Nanoparticles for Improved Food Quality and Safety and Assessement of Their Performance
Food industry has recently prioritized the incorporation of bioactive compounds (e.g., omega-3 fatty acids, phytosterols) to develop health and wellness-promoting foods and beverages. However, many bioactives are lipophilic, sensitive to environmental conditions, some have strong odor and smell, and low bioavailability, which limit their use as functional food ingredients. Therefore, the goal of this research was to develop an innovative and green particle formation process based on supercritical carbon dioxide (SC-CO2) to manufacture bioactive-loaded hollow solid lipid micro- and nanoparticles for improved food quality and safety. Specific objectives were to: (1) study the effect of chemical structure of the solid lipid matrix on melting behavior and volumetric expansion in pressurized CO2, (2) develop fish oil-loaded hollow solid lipid micro- and nanoparticles using SC-CO2, (3) evaluate in vitro bioaccessibility and bioavailability of the fish oil-loaded particles, (4) investigate the performance of the fish oil-loaded particles in a model food, and (5) investigate the effect of lipid matrix on release behavior of the loaded essential oil and to assess antibacterial activity in a model food. A positive correlation between melting point depression and volumetric expansion was observed for the solid lipids in pressurized CO2. Particles were formed at the optimized conditions (50 µm nozzle diameter, 200 bar pressure). Fish oil-loaded particles were spherical and free-flowing. Loading efficiencies up to 97.5% was obtained. Mean particle size was 12 µm and 10% volume of the particles were nano. In vitro bioaccessibility and bioavailability of EPA and DHA increased 2 folds when loaded into hollow particles. When applied to skim milk, the loaded fish oil achieved enhanced bioaccessibility after in vitro digestion and exhibited lower and delayed oxidation. Essential oil-loaded particles showed similar and improved antibacterial activity in skim milk against Gram-negative and Gram-positive bacteria, respectively. This approach has the potential to be transferred to food manufacturers and to convert solid lipids into functional food ingredients for improved food safety, quality, and health benefits.
Yang, Junsi, "Development of Bioactive-Loaded Hollow Solid Lipid Micro- and Nanoparticles for Improved Food Quality and Safety and Assessement of Their Performance" (2021). ETD collection for University of Nebraska - Lincoln. AAI28489941.