The use of carboxymethylcellulose to recover potato proteins and control their functional properties

Carboxymethylcellulose (CMC) has been used as a complexation agent in order to effectively precipitate potato protein at pH 2.5 from a simulated potato processing plant waste effluent and the functional properties of the resulting protein preparation were evaluated. The presence of polysaccharide in the isolated protein at a relatively low concentration resulted, at neutral pH environment in an improvement of its ability to stabilize emulsion and foam systems against creaming and liquid drainage, respectively. These findings are explained on the basis of carboxymethylcellulose–potato protein electrostatic interactions, leading to an increase in protein solubility and also an enhancement of steric repulsive forces between neighboring droplets or bubbles.This is the result of the presence of polysaccharide molecules at the oil- or air-water interface, due to interactions with the surface-active potato proteins. The presence of non-adsorbing CMC in the continuous phase should also be taken into consideration in the case of emulsions. These polymeric molecules can lead to depletion flocculation of oil droplets and in this way affect their creaming behavior.