In the present work we have examined the effects of citric acid which is present in high concentrations in the juice from citrus
fruits on viscosity of pectin. The objective of this work was to provide a procedure for chemical modification of pectin with preserving its molecular weight. The citric acid treatment prior to heat extraction at acidic pH was efficient in altering the physicochemical properties of pectin; the pectin with citric acid treatment in our work contained lower galacturonic acid concentrations compared to transacylated pectin catalyzed by pectinesterase with high molecular mass (Lee, Wu, Lee, Jiang, & Chang, 2003).