Encapsulation of ferulic acid in quinoa protein and zein nanoparticles prepared through antisolvent precipitation: Structure, stability and gastrointestinal digestion

The biological activities of ferulic acid (FA) are limited by poor solubility and instability, which can be improved by encapsulation. Nanoparticles from quinoa protein isolate (QPI) and its fractions (albumin, globulin, and prolamin) were prepared using antisolvent precipitation. These nanoparticles’ environmental stability and encapsulating capability were compared with zein nanoparticles. FA was successfully encapsulated in nanoparticles made from QPI, quinoa prolamin, and zein. Proteins of smaller nanoparticles and lower pI gave higher encapsulation efficiency (EE) and loading capacity (LC). Quinoa prolamin had higher EE (81.2%) and LC (29.7%) than zein (70.7% and 18.5%, respectively). Encapsulating FA with these protein nanoparticles improved the in vitro utilization of FA. QPI and quinoa prolamin nanoparticles exhibited higher gastric resistance than zein nanoparticles. Encapsulation with quinoa prolamin resulted in the highest intestine releasing of FA absorption among all. The results suggested that quinoa prolamin could be promising materials for delivering bioactive compounds. • Quinoa protein isolate (QPI) and its prolamin were able to encapsulate ferulic acid • Quinoa prolamin (QP) had the highest encapsulation efficiency and loading capacity • Nanoparticles of QPI and QP had higher gastric resistance than that of zein • Nanoparticles of QP had higher stability toward temperature and storage among all • Utilization of ferulic acid was increased by 30% in QP nanoparticles