THE EFFECT OF INULIN AND GALACTOOLIGOSACCHARIDES ON PHYSICOCHEMICAL AND SENSORY PROPERTIES OF PREBIOTIC KETCHUP

Introduction: Ketchup is a popular product and since there is a growing rate in the consumption of fast foods and the use of ketchup as the resulte, therefore elevaluation of the behaviour and characteristic value of this product with new formulations such as the addition of prebiotics is desirable. Materials and Methods: In this study, chemical properties (pH, acidity,brix and non soluble solids), physical characteristics (syneresis and color) and sensory properties of  prebiotic ketchup samples containing different amounts of inulin and galactooligosaccharides along other thickeners (modified starch, xanthan and guar gum) using defined standard methods were evaluted. Results: There was no significant difference in the chemical properties between the samples except for the acidity. Prebiotic ketchups containing modified starch had more syneresis as compared to the samples with similar amounts of prebiotic compounds along with xanthan and guar gum. Color values of L*,a*,b* were increased with increasing the prebiotic compounds. In addition, the difference in the total color was higher for prebiotic samples containing modified starch. Although the sensory properties of the prebiotic ketchup samples were influenced by the application of inulin and galactooligosaccharides, but the overall acceptance of most prebiotic samples were not significantly different as compared to the commercial ketchup. Conclusion: According to the results of this study, a prebiotic ketchup might be produced with the acceptable physicochemical and sensory properties by the addition of inulin and galactooligosaccharides to the formulation. The prebiotic samples containing xanthan and guar  showed more similar charactristics  to the commercial product particularly considering the syneresis effect.