Entrapment of β-carotene and zinc in whey protein nanoparticles using the pH cycle method: Evidence of sustained release delivery in intestinal and gastric fluids

Abstract

Nanoparticles prepared from whey protein isolates were used for the entrapment and sustained delivery of β-carotene and Zn ions. The loaded whey protein nanoparticles were prepared using the pH cycle method at an aggregation pH value of 6 and 22 h of ageing time in the presence of Ca ions. The size, morphology, stability and release profiles of the loaded nanoparticles were evaluated at neutral and acidic conditions. Results suggested whey protein nanoparticles entrapped around 97% of the β-carotene and 33% of the Zn ions in spherical compact structures. The retention of β-carotene in prepared nanoparticles at different time points was significantly higher (P < 0.05) relative to the controls. FT-IR data suggested that physical interactions were primarily involved in the entrapment process. The formulated nanoparticles showed higher cargo release profiles reaching 70% after 24 h in neutral conditions even in the presence of proteolytic enzymes.