Effects of basal seed gum and carboxymethyl cellulose gum on rheological properties and flow behavior of pomegranate paste

This study aims to investigate and compare the effect of adding basal seed gum (BSG) and carboxymethyl cellulose gum (CMC) on rheological properties and flow behavior of pomegranate paste. To this end, the pomegranate pastes with three Brix of 30, 45 and 55% were prepared, and the two levels (0.5 or 1% wt/wt) of each BSG and CMC gums were separately added to the paste samples. Strain sweep, frequency sweep and dynamic shear tests were performed for the samples. In summary, increased Brix and gum ratio significantly increased storage modulus (G), loss modulus (G) and complex modulus (G*) in the samples and BSG effect was more highlighted in this relation. All the samples showed a solid-like behavior (G more than G) and the power-law and Herschel-Buckley models were well fitted with the apparent viscosity-shear rate data (R-2>0.990 and R-2>0.986, respectively). Flow behavior index (n, n) calculated using power-law and Herschel-Buckley models was within 0.691-0.797 and 0.205-0.365, respectively. Coefficient of consistency (K, K) calculated by power-law and Herschel-Buckley models was within 34.509-582.100 and 22.719-759.630Pa.s(n), in that order. Increased Brix and gum ratio led to increased coefficient of consistency (K, K), yield stress ((0)) and hysteresis loop in the samples; BSG effect was higher in this regard. In general, adding gums could improve the rheological properties of pomegranate paste via increasing the consistency and elasticity features.