Cryogels from albumin and low methoxyl amidated pectin as a matrix for betalain encapsulation

Abstract

Betalain from beetroot (Beta vulgaris) was encapsulated in cryogels consisting of albumin (ALB) and albumin-pectin (ALB-PEC). The color characteristics, encapsulation efficiency (EE), and release profile, as well as the molecular interactions and morphological characteristics of the cryogels, were evaluated. All of the cryogels had a reddish-purple tonality and showed high EE, with values between 88% and 97%. The release profile was affected by the PEC concentration and the methodology used in the preparation of the cryogels (pre-load or post-load). The betalain release percentage after 4 hr of exposure, ranged between 10%–12% (pH 2), 29%–33% (pH 7), and 26%–31% (pH 10) for pre-loaded cryogels, whereas for post-loaded cryogels, the ranges were 8%–18% (pH 2), 21%–43% (pH 7), and 30%–49% (pH 10).The ALB cryogels showed a compact structure, whereas the ALB-PEC cryogels showed a cohesive and fibrous structures compared with that of the ALB cryogels. Practical application: Cryogels from albumin and low methoxyl amidated pectin can be considered an interesting tool for encapsulation of bioactive compounds such as betalain and formulate functional food. Cryogels are a potential biodegradable matrix as an alternative for a controlled release system of the bioactive compounds.