Sesame protein hydrolysate-gum Arabic Maillard conjugates for loading natural anthocyanins: Characterization, in vitro gastrointestinal digestion and storage stability

Abstract

Protein-polysaccharide conjugates formed via Maillard reaction have the potential as a new type of encapsulation system. However, understanding the effects of the Maillard conjugates as carriers for anthocyanins (ANTs) is limited. The objectives of this study were to develop conjugation of sesame protein hydrolysate (SPH) and gum Arabic (GA) via a wet heating approach with variable times (1, 3, 6, and 12 h) and to investigate the ability of freshly prepared conjugates for encapsulation of Malva Sylvestris (common mallow) ANTs. Conjugate production was confirmed by the appearance of new properties, e.g., altered color, chemical interaction, and changed secondary and tertiary structures. The glycation degree of the conjugates increased to a maximum at 12 h. Conjugation with GA helped the partial unfolding of SPH, and improved its solubility and thermal stability. The ability of SPH, GA, and their conjugate as carriers were compared via the spray drying method. The encapsulation efficiency, morphology and simulated gastrointestinal conditions were investigated. The more homogeneous particles produced by the conjugate ensured greater retention and preservation of ANTs. The release of ANTs during in vitro simulated digestion was significantly slowed by encapsulation, particularly for encapsulated ANTs within the Maillard product. In storage for 90 days at 35 °C, the retention of ANTs was much higher within conjugates (93.13%) compared to nonencapsulated powder (39.76%). This research confirmed that the novel carrier prepared by the controlled Maillard reaction can be a proper wall material in the encapsulation of ANTs.