Structure and stability analyses of collagen hydrolysate coacervates triggered by ethanol in aqueous solution

Abstract

The coacervation of collagen hydrolysate (CH) in aqueous solution was triggered by ethanol as poor solvent which has a significant effect on the aggregation and rearrangement of CH macromolecules. In this work, the static coacervation was performed to investigate the influences on coacervates morphology. CH concentration and ethanol temperature had significant influences on coacervates morphology. Treatment for the CH solution of high concentration by lower temperature ethanol (<25°C) tended to form the microspheres morphology. High temperature ethanol was not conducive to CH coacervation, while enhanced the CH solubilization in water‐ethanol. By directly mixing CH solution and ethanol under agitation, dispersed nanospheres could be successfully obtained in suspension. The turbidity and absorbance tests were carried out to further study the CH coacervation behaviors. The stability of milky suspension induced by ethanol was evaluated by a self‐built light transmittance measurement. The result showed that the absorbance and turbidity of CH suspension increased with increasing the VEtOH ratio and CH concentration. The milky suspension with high VEtOH would turn clear gradually due to the CH solubilization in water–alcohol. The maximum absorbance presented at pH around 7 where the charges of CH molecules were negative. The coacervation behaviors of CH were very different from that of collagen and gelatin, owing to its lower molecular weight.

Structure, extraction, processing, and applications of collagen as an ideal component for biomaterials - a review

“…The colloidal collagen particles do not form precipitation in water due to the effect of the hydration layer and repulsive potential force [87]. In alkaline conditions, the secondary bonds of collagen break down and eventually lead to the destruction of the multi-hierarchical structure of collagen proteins [88].…”