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Advisor(s)
Abstract(s)
Pectic raw material was extracted from the alcohol insoluble residue of olive pomace. After purification, the olive pectic extract (OPE) contained 48% of galacturonic acid (GalA) and 31% of arabinose, in a total sugar content of 72%, and a degree of methylesterification (DM) of 43%. Phase diagrams were established to define the physical state of the OPE/calcium, systems, at pH 3 and 7, as a function of GalA and calcium concentration. The theological properties of the OPE/calcium systems were investigated by small-amplitude oscillatory tests. Kinetics of gel ageing and the viscoelastic properties of the cured gels were evaluated as a function of GalA and calcium concentration at pH 3 and 7. Compared with the observed behaviour of a citrus pectin, taken as representative of a commercial low-methoxyl pectin, the OPE showed higher critical GalA and calcium concentrations for gelation to occur, a larger region corresponding to homogeneous gel, and gels characterised by lower viscoelastic moduli, at similar GalA and calcium concentrations.
Description
Keywords
Olive pomace Pectic polysaccharide Gelation Viscoelastic properties
Citation
Cardoso, Susana M.; Coimbra, Manuel A.; Silva, J.A. Lopes da (2003). Calcium-mediated gelation of an olive pomace pectic extract. Carbohydrate Polymers. ISSN 0144-8617. 52:2, p. 125-133