Abstract
Stress relaxation behaviour of frozen sucrose solutions in the presence of xanthan gum, gelatin and guar gum was investigated using a thermomechanical analyzer. Freezing rate and stabilizer type had a significant influence on the calculated relaxation time (τ) and asymptotic modulus (E a) values at temperatures within and above the glassy state. Following slow (2°C min −1) and rapid freezing (liquid nitrogen) the temperature corresponding to a large reduction in τ was found to correlate well with previously reported T g onset of annealed and non-annealed systems, respectively (−48°C, rapid; −41°C, slow). At −20°C stabilized systems appeared to alter significantly the mechanism of structural relaxation leading to increased τ and short-term viscoelasticity properties determined from E a values, xanthan and gelatin exerting the greatest effect. It is postulated that above the critical concentration stabilizer action may evolve from modification of the kinetics of the unfrozen phase facilitated by changes in free volume distribution specifically altering the rheological and viscoelastic response of systems at sub-zero temperatures.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
