Modeling of Xanthan Gum Effect on Textural Properties of Carrot Cake

Carrot is a rich source of β-carotene, thiamine, riboflavin, fiber and minerals for enrichment of sponge cake. Addition of hydrocolloids on cake formulation improved the sensory and textural properties. For modeling xanthan gum effect on viscoelastic properties of sponge cake enriched with carrot powder, stress relaxation test was done. In this study firstly to increase textural properties of carrot sponge cake, xanthan gum at four levels 0. 0.25. 0.50 and 0.75 %, were added to formulation. After preparing of cakes, stress relaxation test was done by a texture analyzer and coefficients of the Peleg-Normand and the extended Maxwell models were calculated. The results showed that with increasing xanthan gum, initial force and balance force values were decreased 48.69% and 43.93%, respectively. The parameters of Peleg-Normand model include k1 and k2 increased with increasing in xanthan gum percent that indicated increasing in elasticity of the cake. The cakes show solid viscoelastic behavior and by increasing xanthan gum percent, total reduced forces (F1ᝯ) of generalized Maxwell model decreased that reflects the increasing the elasticity. The results of stress relaxation modeling of experimental data by Peleg-Normand and the extended Maxwell models showed that the Maxwell model has more efficient to evaluation of viscoelastic properties of carrot cake with xanthan gum.