EFFECT OF WATER-CONTENT AND SUGARS ON THE GLASS-TRANSITION OF CASEIN AND SODIUM CASEINATE

The glass transitions of casein and sodium caseinate were studied as a function of water content, using differential scanning calorimetry (D SC), dynamic mechanical thermal analysis (DMTA), a mechanical three po int bend test, solid state C-13 nuclear magnetic resonance (NMR) spect roscopy and X-ray diffraction. Glucose and lactose at 10% mass ratio o f anhydrous casein had no effect on the glass transition of casein as a function of water content, although at 50% mass ratio there was some increase in glass transition temperature (T(g)), i.e. an anti-plastic izing effect, with glucose. In contrast, with 50% fructose in sodium c aseinate, there was some plasticizing effect. These results are compar ed with previous results for amylopectin and gluten-sugar mixtures.