Enhancing the resistance of anthocyanins to environmental stress by constructing ovalbumin-propylene glycol alginate nanocarriers with novel configurations

Abstract Ovalbumin (OVA) is the most abundant globular protein in egg white. In this study, the nanocomplexes formed by the protein-polysaccharide system could effectively improve the stability of OVA near isoelectric point and further realize the delivery of anthocyanins (ACNs). The nanocarriers (Type I and Type II) were constructed using OVA-propylene glycol alginate (OVA-PGA) complexes through heating-assisted electrostatic assembly. Type II showed the potential as an admirable nanocarrier, including smaller particle size (328.2 nm), better PDI (0.243), more excellent stability (pH 3–7) as well as fine surface hydrophobicity compared with Type I. In addition, Type II had higher encapsulation efficiency (EE) of ACNs (EE = 96.89%). Fourier transform infrared (FTIR) demonstrated that ACNs was successfully loaded to Type II by hydrogen bonding and electrostatic interactions. The ACNs-loaded Type II (Type II-ACNs) maintained high scavenging activity of ABTS free radical and prevented ACNs from being degraded under different environmental factors (pH, temperature, ascorbic acid and light). In simulated gastrointestinal digestion, Type II-ACNs achieved protection and slow release for ACNs. This study indicates that OVA-PGA nanocomplexes (Type II) with novel configurations can provide guidance for developing ACNs and other bioactive substance delivery systems as food functional ingredients.