Production and characterization of pea protein isolate-pectin complexes for delivery of curcumin: Effect of esterified degree of pectin

This study aimed to develop novel complexes between pea protein isolate (PPI) and pectin as a delivery system for curcumin (Cur). The influence of pectin type and curcumin concentration on physiochemical properties of the complexes and the protective effect of the complexes on stability of curcumin were investigated. The encapsulation efficiency was used to optimize the PPI and Cur mass ratio (40:1 PPI:Cur). PPI-Cur-HMP 40: 1 ternary complex with a hydrodynamic diameter of 559.20 ± 6.16 nm, zeta potential of −14.80 ± 0.56 mV, encapsulation efficiency of 85.49 ± 0.04%, thermal denaturation temperature of 78.43 ± 2.85 °C, provided the strong protection on curcumin against UV-light and thermal degradation, and delayed the release of curcumin in vitro gastrointestinal digestion. The dominant interactions among PPI, curcumin and pectin determined by FTIR were electrostatic attraction, hydrophobic effects and hydrogen-bonding which played important roles in the formation of PPI-Cur-pectin complexes. The present work revealed that the PPI-HMP complex could be an effective delivery system for bioactive compounds with applications in a wide range of functional foods and beverages.