Potential of microencapsulation through emulsion-electrospraying to improve the bioaccesibility of β-carotene

Abstract

The development of carotenoid-enriched functional foods is limited by the low bioaccessibility of these bioactive compounds. The aim of this work was to improve the bioaccessibility of β-carotene after in-vitro digestion through its encapsulation within electrosprayed protein microparticles. Two different protein matrices (zein and a whey protein concentrate, WPC) and two emulsification procedures (high-speed homogenization and ultrasonication) were used to prepare the microcapsules through emulsion-electrospraying, using a soy bean oil as lipid carrier, and the impact of the emulsion properties on the microencapsulation efficiency (MEE) and the bioaccessibility of β-carotene was studied. Results showed that the stability of the prepared emulsions was the main factor affecting the microencapsulation efficiency. The application of an ultrasonic treatment was necessary to stabilize the WPC emulsions and increase the MEE of the WPC microcapsules, but had a slight negative impact on the total β-carotene content of the zein particles, due to thermal degradation of β-carotene, without significantly affecting their MEE. The highest MEE was achieved for the capsules obtained from zein emulsions (34 ± 7%). All the encapsulation structures, except those obtained from WPC emulsions prepared by high-speed homogenization, increased the bioaccessibility of β-carotene after in-vitro digestion, which was negligible in its free form.