بررسی اثر صمغ های بومی دانه مرو و کتیرا بر ویژگی های فیزیکوشیمیایی، رئولوژیکی و حسی سس کچاپ

Ketchup is highly consumed productand hydrocolloids are used as stabilizers in its formulation. In this study, native hydrocolloids of tragacanth gum and sage seed gum were used at levels of 0.5, 0.75 and 1% in ketchup formulation. Two ketchup samples without gum and commercial ketchup were considered as controls. The physicochemical, rheological and sensory properties of the samples were evaluated. Based on the results, samples containing tragacanth gum and sage seed gum had less pH and higher brix thancontrol without gum (p<0.05). The dry matter was decreased by increasing gum concentrations of 0.75 to 1 % and syneresis of ketchup samples was also decreased by addition of native gums and increasing their concentrations (p<0.05). Samples containing higher percentages of native gums and also commercial ketchup had higher brightness (p<0.05). Indeed the color quality of most of the samples were close to the commercial ketchup. In flow measurements, all samples showed pseudoplastic behavior and the 1% of sage seed gum created a zero shear viscosity higher than commercial ketchup (p<0.05).The viscoelastic solid behavior was observed in samples in viscoelastic test and most of the samples had appropriaterheological properties. No significant difference was revealed in the sensory characteristics between samples containing native gums and commercial ketchup. (p>0.05). The results of this study showed that ketchup with proper quality can be produced by using tragacanth and sage seed gum that it can be competitive withcommercial ketchup especially at higher concentrations.