Main content area

Coencapsulation of (−)-Epigallocatechin-3-gallate and Quercetin in Particle-Stabilized W/O/W Emulsion Gels: Controlled Release and Bioaccessibility

Chen, Xing, McClements, David Julian, Wang, Jian, Zou, Liqiang, Deng, Sumeng, Liu, Wei, Yan, Chi, Zhu, Yuqing, Cheng, Ce, Liu, Chengmei
Journal of agricultural and food chemistry 2018 v.66 no.14 pp. 3691-3699
bioavailability, emulsions, encapsulation, epigallocatechin gallate, gastrointestinal system, gelatin, gliadin, hydrophilicity, hydrophobicity, lipophilicity, nanoparticles, oils, osmotic stress, pH, polyglycerol polyricinoleate, quercetin, separation, solubility, surfactants, wheat
Particle-stabilized W₁/O/W₂ emulsion gels were fabricated using a two-step procedure: (i) a W₁/O emulsion was formed containing saccharose (for osmotic stress balance) and gelatin (as a gelling agent) in the aqueous phase and polyglycerol polyricinoleate (a lipophilic surfactant) in the oil phase; (ii) this W₁/O emulsion was then homogenized with another water phase (W₂) containing wheat gliadin nanoparticles (hydrophilic emulsifier). The gliadin nanoparticles in the external aqueous phase aggregated at pH 5.5, which led to the formation of particle-stabilized W₁/O/W₂ emulsion gels with good stability to phase separation. These emulsion gels were then used to coencapsulate a hydrophilic bioactive (epigallocatechin-3-gallate, EGCG) in the internal aqueous phase (encapsulation efficiency = 65.5%) and a hydrophobic bioactive (quercetin) in the oil phase (encapsulation efficiency = 97.2%). The emulsion gels improved EGCG chemical stability and quercetin solubility under simulated gastrointestinal conditions, which led to a 2- and 4-fold increase in their effective bioaccessibility, respectively.