Microencapsulation by spray drying of omega-3 lipids extracted from oilseeds and microalgae: Effect on polyunsaturated fatty acid composition

In this work, microencapsulation of omega-3 lipids from sustainable sources, including oilseeds such as Salvia hispanica L., Echium plantagineum L. and Camelina sativa L., microalgal lipids (from Nannochloropsis gaditana) and enzymatically produced fatty acid ethyl esters (FAEEs), was successfully done by spray drying and their outcomes studied. Previous to microencapsulation process, lipid extracts from new omega-3 sources (chia, camelina and echium oilseeds and wet microalgal biomass of Nannochloropsis) were produced using Pressurized Liquid Extraction. The best microencapsulation efficiency was achieved for chia FAEEs (76.9%), while the lowest was obtained for camelina oil (58.8%) and Nannochloropsis gaditana lipids (57.0%) microcapsules, which also showed low emulsion stability. Analysis by GC-MS showed that microencapsulation process did not negatively affect omega-3 fatty acid profile of microencapsulated extracts. The percentage of omega-3 in each used lipid was similar before and after spray drying (no significant differences at 5% level). Under the optimal conditions, produced microcapsules ranged from 1.5 to 30 μm and showed spherical shape and smooth surface without cracks. Thus, the proposed method provides an original approach to produce omega-3 microencapsulated lipid extracts from different nature, with high microencapsulation efficiency and payload, for potential applications in the development of foods enriched in omega-3 fatty acids.