Rheological effect of gum addition to hot pepper-soybean pastes

The effect of four different gums [carboxylmethylcellulose (CMC), guar gum, hydroxypropylmethylcellulose (HPMC) and tara gum] at 0.5% concentration on rheological properties of fermented hot pepper soybean paste (HPSP) was evaluated in steady and dynamic shear. HPSP-gum mixture samples at 25 degrees C are highly shear thinning fluids with high yield stresses. All gums increased the consistency index (K) and apparent viscosity (eta(a,100)) of HPSP. Apparent viscosity of all samples obeyed the Arrhenius temperature relationship. Dynamic moduli (G', G" and eta*) values of HPSP-gum mixtures were higher than those of HPSP with no added gum over most of the frequency range. Dynamic moduli, K and eta(a,100) values were increased in the presence of gums, and increased in the following order: control < CMC < guar gum < tara gum < HPMC. The Cox-Merz rule did not describe the relationship between dynamic (eta*) and steady shear viscosities (eta(a)) for all samples.