Viscoelastic properties of aqueous and milk systems with carboxymethyl cellulose

Carboxymethyl cellulose (CMC) is widely used as a stabilizer and thickener in the food industry. Previously published work has been carried out in predominantly monophasic systems, i.e. aqueous solutions, but there are few studies of complex systems like dairy desserts where CMC may interact with carbohydrates and milk proteins. Oscillatory rheological methods were used to study the influence of CMC concentration (0.75%, 1.00%, 1.25% and 1.50% w/w) and type of dispersing media (aqueous solution, skimmed milk and whole milk) on the viscoelastic properties of aqueous and milk systems. Both the type of dispersing media and the CMC concentration clearly affected the viscoelastic behaviour of samples, which ranged from fluid-like to weak gel. At the lowest CMC concentration (0.75% w/w), no significant differences in G′, G″ and η* values at 6.28 rad/s were observed between the three systems studied. At the highest CMC concentration (1.5% w/w) G′ and η* values at 6.28 rad/s were significantly higher for whole-milk samples than for skimmed-milk samples, which in turn were higher than for aqueous solutions.