Exploring the performance of amaranth grain starch and protein microcapsules as -carotene carrier systems for food applications

Abstract

Underexploited sources of bio-based wall materials for bioactive compounds (such as -carotene) encapsulation have gained increasing interest within the scientific community. In this study, the potential of amaranth (Amaranthus cruentus) grain starch and protein rich fractions as microcapsules wall materials to carrier -carotene was evaluated. Microcapsules were produced by spray-drying and their morphological and physicochemical characterization was carried out. The microcapsules presented a spherical shape (particle size distribution: 0.3 - 30 m) and encapsulation efficiencies ranging from 64 to 69%. Results showed that protein-based microcapsules had better -carotene storage stability as compared to starch-based microcapsules (at 8 and 25 ºC). -carotene release kinetics at 37 ºC and pH 7.4 could be mainly described by structural-relaxation phenomenon using the linear superposition model. Moreover, encapsulated -carotene exhibited higher bioaccessibility than its free form after simulated in vitro digestion tests. Microcapsules did not affect cell viability at 0.0625mg·L-1 of -carotene. Thus, amaranth grain biopolymers-based microcapsules were successfully developed as promising -carotene delivery systems to be added to food products and consequently, to improve their functionality.