Nanoencapsulation of Anthocyanins from Red Cabbage (Brassica oleracea L. var. Capitata f. rubra) through Coacervation of Whey Protein Isolate and Apple High Methoxyl Pectin

• Published in: Antioxidants Vol. 12; no. 9; p. 1757
• Main Authors: Fierri, Ilaria, De Marchi, Laura, Chignola, Roberto, Rossin, Giacomo, Bellumori, Maria, Perbellini, Anna, Mancini, Ines, Romeo, Alessandro, Ischia, Gloria, Saorin, Asia, Mainente, Federica, Zoccatelli, Gianni
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2023; MDPI
• Subjects: Acylation; Anthocyanin; Anthocyanins; Antioxidants; Brassica oleracea; Coacervation; Efficiency; Encapsulation; Glycosylation; high-methoxyl pectin; Ions; Milk proteins; Nanoparticles; Pectin; Phenolic compounds; Proteins; red cabbage; Whey protein; whey protein isolate; Germany; Palo Alto California; Italy; United States > US; Europe
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox12091757

Encapsulation is a valuable strategy to protect and deliver anthocyanins (ACNs), phenolic compounds with outstanding antioxidant capacity but limited stability. In this study, coacervation was used to encapsulate an ACN-rich red cabbage extract (RCE). Two agri-food by-product polymers, whey protein isolate (WPI) and apple high-methoxyl pectin (HMP), were blended at pH 4.0 in a specific ratio to induce the formation of nanoparticles (NPs). The process optimisation yielded a monodispersed population (PDI < 0.200) of negatively charged (−17 mV) NPs with an average diameter of 380 nm. RCE concentration influenced size, charge, and antioxidant capacity in a dose-dependent manner. NPs were also sensitive to pH increases from 4 to 7, showing a progressive breakdown. The encapsulation efficiency was 30%, with the retention of ACNs within the polymeric matrix being influenced by their chemical structure: diacylated and/or C3-triglucoside forms were more efficiently encapsulated than monoacylated C3-diglucosides. In conclusion, we report a promising, simple, and sustainable method to produce monodispersed NPs for ACN encapsulation and delivery. Evidence of differential binding of ACNs to NPs, dependent on specific acylation/glycosylation patterns, indicates that care must be taken in the choice of the appropriate NP formulation for the encapsulation of phenolic compounds.