Homogenization-dependent stability and bioavailability of bee pollen extract–loaded liposomes

This study presents a comprehensive comparison of microfluidization and ultrasonication homogenization methods for producing primary and chitosan-coated secondary liposomes loaded with bee pollen extract (PE). The gastrointestinal stability, transepithelial transport (Caco-2 model), and bread-matrix applicability of these systems were then investigated in terms of the bioaccessibility and bioavailability of TPC, TFC, and antioxidant capacity (DPPH and CUPRAC). Both ultrasonication and microfluidization was found to be effective in producing primary and secondary liposomes with varying characteristics, including particle size (80.71 –118.60 nm) and surface charge (-27.90 mV to + 50.17 mV). Encapsulation efficiency was notably enhanced by ultrasonication, reaching 78.58%. During gastrointestinal digestion, the ultrasonication application exhibited high stability in TPC, TFC and antioxidant activity (CUPRAC and DPPH), leading to high bioaccessibility values at the highest PE concentration (72.01% for TPC, 86.50% for TFC, 70.90% for CUPRAC, and 58.93% for DPPH). In the in vitro intestinal transport model, the bioavailability of TPC, TFC, CUPRAC, and DPPH from fortified bread was determined as 32.06%, 63.20%, 81.67%, and 24.63%, respectively. These findings demonstrate that liposomal encapsulation homogenized by ultrasonication can effectively improve the stability, delivery, and functional performance of pollen bioactive compounds. This study introduces a novel approach to enhancing the nutritional value and health-promoting properties of food products by incorporating liposomal encapsulated PE into bread.