Stress Relaxation of Fruit Gels. Evaluation of Models and Effects of Composition |
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| Authors: | M. GAMERO,S.M. FISZMAN,L. DURÁ N |
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| Affiliation: | The authors are associated with lnstituto de Agroquimica y Tecnologia de Alimentos (C.S.I.C.), Jaime Roig, 11. 46010 Valencia, Spain. |
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| Abstract: | Stress relaxation behavior of kappa carrageenan (1%) gels (C) and kappa carrageenan (0.5%) plus locust bean gum (0.5%) gels (G) was studied. Effects of addition of sugar (18.3, 36.6 and 55° Brix) and fruit pulp (15%) on relaxation response were analyzed. Curves were fitted to Maxwell (M), Peleg (P) and simplified Maxwell (SM) equations. All three equations were valid to quantify relaxation behavior of fruit gels and to evaluate the effects of changes in composition, with P and SM equations being simpler. Locust bean gum increased initial stress decay rate and decreased proportion of unrelaxed force. Sucrose produced the opposite effect. Fruit pulp effects were weak and dependent on gelling system. |
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| Keywords: | fruit stress relaxation gel strength carrageenan locust bean gum |
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