Abstract

The stability of liposomes is fundamental for incorporating polyphenols into foods, but their applicability depends on the drying method. Drying can modify particle properties, bioactive retention, and the economic-environmental impact. Therefore, comparing different drying methods is key to selecting the most suitable alternative. This study evaluated freeze-drying, microwave vacuum drying, and spray drying to determine their effects on particle properties, energy, and environmental performance. Liposomes were formulated using chitosan concentrations of 0.1 %-1 % and homogenized at 13,500 rpm for 2-10 min. Response Surface Methodology was applied to optimize particle size and encapsulation efficiency, identifying 0.1 % chitosan and 10 min of homogenization as the optimal conditions. Freeze-drying provided the highest polyphenol retention (517.83 mg/ g GAE) and antioxidant activity (40.64 %) but resulted in powders with a relatively high moisture content. Vacuum microwave drying significantly reduced CO2 emissions (8.06 kg CO2/kg) and processing time, offering a more sustainable alternative. Spray drying produced the smallest particle size (593 nm), the lowest moisture content (1.26 %), and the highest solubility (87.36 %), yielding powders with superior technological performance and stability. While spray drying required more energy than vacuum microwave drying, it demonstrated the best balance between quality, scalability, and environmental sustainability. This study highlights, for the first time, the application of microwave drying to liposome drying, as well as the study of energy efficiency and CO2 emissions in liposome drying technologies. Overall, spray drying has the potential for a viable industrial stage in the production of chitosan-coated liposomal powders intended for functional food applications.