Nanoparticles of kaempferol loaded in deamidated zein/pectin protein: Formation, stability, improved antioxidant capacity, and enhanced bioaccessibility

Kaempferol is a dietary polyphenol with abundant bioactivities such as anti-inflammatory, antioxidant and anticancer. However, its poor bioavailability limits the utilization. Therefore, food-grade delivery formulations are explored to overcome it. In this study, kaempferol was loaded into deamidated zein/pectin to prepare complex nanoparticles (KZN) with a diameter of 158.3 nm and loading efficiency of 89.54%. The kaempferol exists in amorphous form within the complex nanoparticles. Fourier transform infrared spectroscopy suggested hydrogen bonding and electrostatic interactions were the main force holding these complexes together. Heating, sodium chloride addition and pH changes did not result in aggregation of KZN. Compared with free kaempferol, the bioaccessibility of kaempferol complexed with zein nanoparticle was enhanced 2-fold, which attributed to higher antioxidant activities. Overall, this study indicates that the KZN had great potential as a delivery technique for hydrophobic compounds in nutraceutical and pharmaceutical applications.