Hard Biodegradable Biopolymer Obtained from Whey Protein Concentrate and Montmorillonite

The aim of this study was to obtain whey protein concentrate-WPC/montmorillonite-MON biopolymers. Mixed whey protein/montmorillonite biopolymers were formed as heat-induced gels and hardened by water evaporation. Increase in protein concentration caused an increase in storage and loss moduli of the gels. Adding 5 % of MON to whey protein gel matrix caused an increase in the moduli value. Obtained biopolymers behaved as weak physical gels as loss tangent was in a range 0.25-0.45. Increase in protein concentration and addition of MON caused increase in viscosity of the biopolymers measured by dissipation of ultrasound vibrations. Addition of MON generally caused reinforcement of the structure of the mixed gels and the material was more resistant to puncture. Addition of MON caused changes in the microstructure of whey protein gel, which became more fine-stranded. It was probably caused by adsorption of the ions by MON. Drying of WPC/MON gels caused formation of very hard biopolymer, which can be applied as natural biodegradable material.