Association between Lysozyme and Carboxymethyl Konjac Glucomannan to Produce Dispersible Coacervates

Lysozyme was subjected to coacervate with carboxymethyl konjac glucomannan (CMKGM) to check if dispersible coacervates could be formed to extend its application in edible antibacterial coating. The results indicated that complex coacervation could occur between the two polyelectrolytes within a narrow pH range from pH 2.5 to 6.0 and the greatest interaction was recorded at 35 °C in the absence of NaCl. The dispersion status of the lysozyme – CMKGM coacervates was closely related to the phase separation pH as well as lysozyme to CMKGM mixing ratio and conditions that led to the presence of free CMKGM in the aqueous phase favored the formation of dispersible coacervates. Rheological measurements revealed that the high viscosity of CMKGM solution contributed greatly to the dispersion status of the lysozyme – CMKGM coacervates. Association with CMKGM caused structural changes to lysozyme, but only slightly affected its lytic activity. Contact angle measurement revealed that the lysozyme – CMKGM coacervates were more hydrophobic than the two single polyelectrolytes. Hence, the dispersible lysozyme – CMKGM coacervates were potential in the fabrication of composite antibacterial edible coatings. Graphical Abstract