Chitosan-cellulose nanocrystal microencapsulation to improve encapsulation efficiency and stability of entrapped fruit anthocyanins

Abstract

For improving stability of fruit anthocyanins (ACN), this study investigated the use of cellulose nanocrystal (CNC) as a macroion crosslinking agent to develop blueberry anthocyanin extract (BB)-loaded chitosan (CH)-CNC microcapsules, and compared with CH-sodium tripolyphosphate (TPP) ones. The yield of microcapsules (∼6.9g) and total monomeric anthocyanin recovery (∼94%) were significantly (P<0.05) higher in CH-CNC microcapsules than those (∼0.3g and ∼33%, respectively) in CH-TPP microcapsules. ACN distribution (%) in CH-CNC microcapsules was 61% on the surfaces, 12% bound with the matrix, and 27% in cores, but that in CH-TPP microcapsules was mostly presented on the surfaces (99%). CH-CNC microcapsules were more stable at pH 7.4 buffer by showing less ACN release (%) than that of CH-TPP, but no difference at pH 1.2. CH-CNC and CH-TPP microcapsules showed different structural and morphological properties. This study demonstrated that CNC is a promising crosslinking agent forming stable BB-loaded CH microcapsules.

Keywords: Blueberry anthocyanin; Cellulose nanocrystal; Chitosan; Ionic gelation encapsulation.