Fabrication and characterisation of milk proteins-chitosan complex coacervates

Abstract

In this paper, the complex coacervate phenomenon between milk proteins (MP) and chitosan of low (LC), medium (MC), and high (HC) molecular mass was studied. Factors influencing the optimal conditions of a coacervate formation such as chitosan molecular mass, protein-to-chitosan ratio, and pH variation were investigated. Using the results of Fourier-transform infrared spectroscopy (FTIR), particle size, zeta potential, and turbidity, a better insight into phase separation and formation of complex coacervate was obtained. Optimum complex coacervation occurred between milk proteins and LC at pH 4.6 and protein to chitosan ratio of 5:1, MC at pH 5.5 and ratio of 10:1, and HC at pH 6.7 and ratio of 15:1. Complex coacervate yields under optimal conditions for LC, MC and HC were 82%, 89%, and 97%, respectively. The findings of the present research can contribute to separating and purifying milk proteins using the complex coacervate method.