Effect of mushroom powder on viscoelastic properties of sponge cake using stress relaxation test

To investigate the effect of replacing dried mushroom on viscoelastic properties of sponge cake, stress relaxation test was done. Mushrooms were dried in optimal conditions, and then mushroom powder was used for enrichment of sponge cake at four levels of 0, 5, 10 and 15 % as substitute of wheat flour in the formulation. After preparing the samples, stress relaxation test was done by a texture analyzer in storage time and coefficients of the Peleg-Normand and the extended Maxwell models were calculated. The results showed that with increasing substitution of mushroom powder initial force and balance force values were decreased. During storage time of cake, initial force and balance force values were increased. The parameters of Peleg-Normand model include k1 and k2 decreased with time that indicating a reduced elasticity of the cake with the passage of time. The cakes show solid viscoelastic behavior and by increasing replacement, total reduced forces (F1ᝯ) of generalized Maxwell model decreased that reflects the increasing of 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 rich sponge cake with mushrooms powder.