Im. Alruqaie et al., STRUCTURAL-PROPERTIES OF PECTIN-GELATIN GELS - PART II - EFFECT OF SUCROSE GLUCOSE SYRUP/, Carbohydrate polymers, 34(4), 1997, pp. 309-321
Small deformation dynamic oscillation and bright field microscopy were
used to examine the structural properties of single and mixed high me
thoxy pectin and gelatin systems in the presence of sucrose/glucose sy
rup blends. Go-solute concentrated (greater than or equal to 78%) syst
ems of the polysaccharide form rubbery structures which are readily tr
ansformed into glassy consistencies according to the time-temperature
superposition principle. Increasing amounts of co-solute in the gelati
n samples induce changes in viscoelasticity from that of conventional
hydrogels to mechanical traces that cover much of the plateau region a
nd the beginning of the glass transition area. Furthermore, manipulati
on of the protein/sugar ratio can result in strong crystalline matrice
s, or viscoelastic solutions where the co-solute forms the continuous
phase and the gelatin inclusions can undertake a conformational transi
tion. The properties of the single components were used to rationalise
the phase behaviour of their mixtures. Upon triggering the gelation o
f pectin, mixtures call be made where either gelatin or both component
s form a continuous phase. Results are discussed in the light of evide
nce obtained from the ethylene glycol work in Part I. (C) 1998 Publish
ed by Elsevier Science Ltd. All rights reserved.