Main content area

Encapsulation of omega-3 fatty acids in nanoemulsions and microgels: Impact of delivery system type and protein addition on gastrointestinal fate

Chen, Fang, Fan, Guang-Qin, Zhang, Zipei, Zhang, Ruojie, Deng, Ze-Yuan, McClements, David Julian
Food research international 2017 v.100 pp. 387-395
antioxidants, beverages, calcium alginate, caseinates, digestion, droplets, encapsulation, free fatty acids, functional foods, humans, hydrogels, linseed oil, nanoemulsions, omega-3 fatty acids, oxidation, oxidative stability, small intestine
Carefully designed delivery systems are required to encapsulate and protect omega-3 fatty acids in commercial food and beverage products, but then release them at the required site-of-action within the human gastrointestinal tract (GIT). Previously, we showed that the oxidative stability of flaxseed oil (a plant-based source of omega-3 fatty acids) encapsulated in nanoemulsion droplets or calcium alginate microgels (hydrogel beads) was improved using caseinate as a natural antioxidant. In this study, the impact of caseinate on the digestion of flaxseed oil encapsulated in these delivery systems was investigated using a simulated GIT. The flaxseed oil was incorporated into four delivery systems: nanoemulsions (NE); nanoemulsions mixed with caseinate (NE+C); hydrogel beads (HB); and, hydrogel beads containing caseinate (HB+C). The gastrointestinal fate of the flaxseed oil droplets depended on delivery system type and the presence of protein. The flaxseed oil in the nanoemulsions (NE and NE+C) was rapidly hydrolyzed within the simulated small intestine, with over 76% and 65% of free fatty acids (FFAs) being released in the first 5 minutes, respectively. Conversely, the flaxseed oil in the hydrogel beads (HB and HB+C) was digested much more slowly, with only around 37% and 22% being released in the same period. This knowledge may be useful for designing delivery systems to protect omega-3 fatty acids from oxidation in functional foods, while still allowing them to be released in the GIT.