JOURNAL OF FOOD PROCESS ENGINEERING, vol.40, no.3, 2017 (SCI-Expanded)
Hydrogels are usually prepared from hydrophilic polymers and when different types of polymers are blended or emulsified with an oil phase the resulting gel is usually known as a composite gel. The objective of this study was to analyze the water uptake characteristics of whey protein-polysaccharide containing composite hydrogels. Composite and composite emulsion gels were formulated in this study using whey protein, xanthan (XN), pectin (PC), alginate (AL), and sunflower oil. Water absorption of hydrogels was studied using Nuclear Magnetic Resonance (NMR) relaxometry through transverse relaxation time (T-2) measurements, and Non-Negative-Least-Square (NNLS) analysis. Swelling ratios (SR) of different gels were determined. Swelling of the gels was also evaluated mathematically and water uptake of hydrogels was explained by the power law model and diffusion rate constants based on power law model were determined. Results showed that NMR relaxometry could be used to differentiate water uptake mechanisms of composite hydrogels.