In this study, acid-thinned starch was blended with konjac glucomannan or psyllium husk powder at a concentration of 3% w/w (starch basis). The blends were characterized by pasting analysis and rheological
properties evaluation. Jelly candy was made from the blends and textural characteristics were studied. Pasting analysis showed that both gums were found to significantly increase some of the pasting parameters, such as peak viscosity, trough, breakdown, final viscosity and setback values. From the frequency sweep, it was found that addition of konjac glucomanan or psyllium husk powder increased the storage modulus (G’) and loss modulus (G’’) values, with psyllium added sample showing more prominent effect than konjac added ones, when compared to the control samples. All samples were found to demonstrate thixotropic flow behaviour. Jelly candy texture profile analysis revealed that konjac glucomannan or psyllium husk powder addition, although decreasing chewability, but rendered the jelly candy less sticky.
The effects of food gums addition on wheat dough freeze-thaw and frozen storage stability were studied. Thermal and dynamic mechanical properties of frozen wheat dough without yeast addition were
determined by means of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA).
DSC results revealed that food gums showed the ability to increase freeze-thaw stability in frozen-stored
samples wherein lower difference in melting enthalpy between first and second freeze-thaw cycle was shown. Based on DMA results, in general, difference between Tg’ and storage temperature (- 18°C) of dough became smaller upon addition of food gums. This may have a practical implication whereby the unfrozen phase could be better protected against physical degradation.