EFFECTS OF FRUIT PULP AND SUCROSE ON THE COMPRESSION RESPONSE OF DIFFERENT POLYSACCHARIDES GEL SYSTEMS

Effects of addition of increasing proportions of peach pulp (10-40%) to three different polysaccharide gel systems - 0.75% kappa-carrageenan. 0.75% kappa-carrageenan plus 0.3% locust bean gum, and 1% alginate - on their compression behaviour were studied. both in the absence and presence of sucrose. Addition of peach pulp to carrageenan-based gels decreased both the maximum rupture force and deformability modulus values but no effect was detected in alginate gels. When 55% sucrose was incorporated to carrageenan-based systems. pulp addition rendered weaker (less firm and less resistant to rupture) gels. In kappa-carrageenan plus locust bean gum mixed gels. where sucrose produced a clear loss of rupture resistance pulp addition reinforced this negative sugar effect and very fragile gels were obtained. In alginate gels with incorporated sucrose. initially stronger than the corresponding water gels. pulp addition also produced decreases in both compression parameters. rendering gels still more resistant to rupture than those without sucrose but less firm than those when the pulp content was over 20%.