The utilization of oat polar lipids produced by supercritical fluid technologies in the encapsulation of probiotics

- A model for the production of oat polar lipids with supercritical fluid techniques is proposed.
- Oat polar lipids were showed to have protective properties in encapsulation of probiotics.
- A stabilization method to improve the shelf life of probiotic products was developed.

Oats contain ingredients that have potential health-promoting properties. Oat lipids contain several essential fatty acids. The polar lipids in oats include glycolipids and phospholipids, which are typically extracted from oat flakes with polar organic solvents. Supercritical carbon dioxide (SC-CO2) has been proposed as an alternative to organic solvents in the food sector for environmental and safety reasons. SC-CO2 was used in this study without and with ethanol as a co-solvent to isolate the polar lipid fractions from oat flakes with or without heat treatments. The polar lipids were collected as a solution in ethanol and precipitated using SC-CO2 as an antisolvent. The fatty acid compositions of different lipid fractions were determined. The precipitated oat polar lipids were tested as an encapsulative and protective agent of probiotics in a human digestive tract simulation. The protective effects of the oat polar lipids were evaluated by measuring the gas production, microbial activity, acetic and lactic acid production, and pH changes in different test mediums. The results demonstrate that the oat polar lipids are able to protect Bifidobacterium breve in a phosphate buffer, thereby providing a useful stabilization method to improve the shelf life of probiotic products.