Quinoa protein-based Buriti oil nanoparticles: Enhancement of antioxidant activity and inhibition of digestive enzymes

Buriti oil offers various biological properties. Nanoencapsulation improves its stability, acceptability, handling, and release of bioactives. In alignment with sustainability trends, plant-based proteins such as quinoa protein are gaining attention as coatings, especially for vegan foods, due to their emulsifying and adsorption properties. This study aimed to formulate and characterize buriti oil nanoparticles based on quinoa protein alone or combined with sodium alginate. The particles were characterized by different physical and chemical methods and evaluated for their bioactive potential by assessing total antioxidant capacity and total phenolic compounds, and their ability to inhibit α-amylase, α-glucosidase, and amyloglucosidase enzymes. They were also evaluated in vitro for cytotoxicity using Chinese hamster ovary (CHO-K1) and human hepatocarcinoma (HepG2) cells. Nanoparticles based on quinoa protein at 4 % w/v (Q4) and 3 % w/v in combination with 1 % w/v sodium alginate (Q3) presented smooth surfaces, with an average size ranging from 357 ± 47 to 270 ± 39 nm, and encapsulation efficiency of 95.6 ± 0.2 % and 94.0 ± 1.0 %, respectively. Nanoencapsulation promoted enhanced antioxidant activity of buriti oil, even at a ten-fold lower oil concentration in the nanoformulations (p < 0.05). Q3 and Q4 also enhanced inhibition of the α-amylase (by 88 %), α-glucosidase (5–24 times more), and amyloglucosidase (by 40 %) compared to free oil (p < 0.05). Nanoparticles did not show cytotoxic effects (cell viability >90 %). Based on current results, using quinoa protein to encapsulate buriti oil could be a promising alternative for developing innovative and sustainable products, with the added value of having bioactive potential.