Improved protective and controlled releasing effect of flaxseed oil microcapsules with glycosylated casein as wall materials

Abstract

The primary objective of this study was to explore the viability of employing casein-pectin conjugate (CA-CP conjugate) or casein-arabinogalactan conjugate (CA-AG conjugate) as wall materials for flaxseed oil microcapsules. Compared with casein, both the CA-CP conjugate and CA-AG conjugate exhibited elevated emulsifying and antioxidant characteristics and therefore, have potential as microencapsulation wall materials. Hence, flaxseed oil microcapsules were prepared using CA-CP conjugate or CA-AG conjugate as wall materials through spray-drying. When the mass ratio of wall material to core material was 1:1, the encapsulation efficiency (EE) of the prepared CA-CP conjugate + flaxseed oil microcapsules (CPM) and CA-AG conjugate + flaxseed oil microcapsules (AGM) reached 72.23% and 83.44%, respectively. Fourier infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) results demonstrated that the microcapsules had smooth surfaces, overall spherical shapes, and successful encapsulation of flaxseed oil by the wall materials. Additionally, in vitro simulated gastrointestinal digestion and antioxidant analysis indicated that the microcapsules achieved controlled release of flaxseed oil in the gastrointestinal tract and improved its storage stability. Therefore, utilizing Maillard reaction products for the microencapsulation of flaxseed oil is a highly promising preservation method.