Utilization of Guazuma ulmifolia gum and sodium alginate to form protective beads of antioxidant peptides obtained from Phaseolus lunatus

Effect of peptides obtained from Phaseolus lunatus L. where biological properties such as antioxidant activity have been found. In addition to improve this beneficial effect, the microencapsulation could be a way to protect the peptides against the environment to which they are exposed. Gums extracted from plant seeds are a potential option such as Guazuma ulmifolia, and its seeds gum exhibits promising properties as coating materials in encapsulation. Two peptide fractions from P. lunatus L. were encapsulated (>10 and <10 kDa) by ionic gelation using mixtures of G. ulmifolia gum and sodium alginate (GUG:SA). A 23 experimental design was used: GUG:SA ratios (A) (70:30 or 30:70); CaCl2 concentrations (B) (0.05 or 0.15 M); and hardening time (C). (10 or 30 min). Multiple variable response analysis with a desirability coefficient identified optimum conditions for each peptide fraction. Better results were obtained for >10 kDa peptide fraction at optimal conditions of A: 70:30, B: 0.05 and C: 10, obtaining irregular beads with a diameter of 5.85 mm2, Bead Encapsulation efficiency 42% and 31 and 42 mM TEAC for ABTS and DPPH respectively. These results shown that GUG:SA mixture is a viable encapsulation system for preserving antioxidant peptide fractions.