M. Rinaudo, Relation between the molecular structure of some polysaccharides and original properties in sol and gel states, FOOD HYDROC, 15(4-6), 2001, pp. 433-440
This paper concerns the properties of a few natural polysaccharides investi
gated in our laboratory. We also present the different techniques used in o
ur group for a long time and their advantages to characterize polysaccharid
es. In a first part, the behavior of galactomannans with different chemical
structures is discussed; the distribution of galactose units along the man
nan backbone is very important. Then, xanthan is developed as one of the be
st thickening polymers due to its high intrinsic stiffness related to the h
elical conformation stabilized in the presence of excess salt. Gellan under
native or deacylated structure is described to demonstrate the role of sub
stituents on the physical properties in solution and especially on the sol-
gel transition. The last part concerns the cooperative interaction between
xanthan and galactomannan giving in specific conditions two different gels
with a gel-sol melting transition around 25 degreesC and 50-60 degreesC, re
spectively, depending on the galactomannan microstructure. (C) 2001 Elsevie
r Science Ltd. AB rights reserved.