Abstract
Pea protein is one of the few hypoallergenic vegetable proteins without genetic modification issues. Pea protein isolate (PPI) is a natural emulsifier with high nutritional value. Nevertheless, PPI's applications in foods are limited by its relatively poor solubility and functional properties. This study was performed to explore the use of a pH-shifting and sonication combined treatment to modify the functional properties of PPI and use the soluble pea protein nanoaggregates produced by the method as base materials to form nanoemulsion and nanocomplex. The ability of these nanocarriers to protect cholecalciferol (vitamin D3) against UV radiation was examined. The stability of nanostructures during storage, antioxidant capacity, and in vitro digestion was evaluated. Generally, the modified PPI-prepared nanoemulsions over-performed the nanocomplexes in all experiments and both showed good protection of vitamin D3 against UV radiation. The stability of the pea protein nanostructures was confirmed in 30-day storage. An improved antioxidant capacity was observed in the ultrasound-treated pea proteins. The modified PPI-prepared nanoemulsions exhibited a significantly higher recovery of vitamin D3 in micelles through in vitro digestion. Therefore, the modified PPI-prepared nanoemulsion may be used as a good natural carrier for protection and delivery of health-promoting compounds in foods.