A Comparative study on the functional properties of carboxymethyl cellulose produced from sugar-beet pulp and other thickeners in tomato ketchup

Sugar-beet pulp، one of the byproducts of sugar industries، contains several important components such as pectin، cellulose and hemicellulose. In this study، firstly cellulose was extracted from sugar-beet pulp. The extracted cellulose was then converted to carboxymethyl cellulose (CMC) by an etherification process preformed at 70 oC. Degree of substitution، purity and moisture content of the CMC were، 0. 52، 53% and 7%، respectively. The properties of the produced CMC was compared with other thickeners (i e. commercial CMC (Merck)، tragacanth gum and a formulated commercial gum (available in the market). All four hydrocolloids were used in the formulation of tomato ketchup at 1% level. The chemical composition، rheological properties، syneresis and sensory evaluation tests were performed. There was no significant difference between the samples in terms of chemical composition. The viscosity of the ketchup samples with beet pulp CMC was much greater than the control without gum، but lower than the samples containing other gums. A slight syneresis was also seen in the samples with beet pulp CMC after one month of storage. Sensory scores of the samples with beet pulp CMC was greater than other samples. Overall، in despite of low purity and DS of the produced CMC، beet pulp CMC has a good potential to be used in food products as a thickener.