Viscosity and Gelling Characteristics of Sunflower Pectin As Affected by Chemical and Physical Factors

The effect of pH, buffer solution, buffer concentration, pectin concentration, and heating on the viscosity of sunflower pectin was studied. The sunflower pectin in all buffers and at all buffer concentrations had the highest viscosities at pH 3. Generally, the viscosity increased with the increase of pectin concentration. The effect of buffer concentration on viscosity was dependent upon the pH, pectin concentration, and heating. Sunflower pectin in sodium citrate buffer had a higher viscosity than pectin in other buffers. The effect of heating on viscosity was dependent upon the pH of the buffer. Gelling heat reversibility of the isolated sunflower pectin was determined and compared with that of two commercial citrus pectins. Jellies of sunflower pectin had good heat reversibility over a wide range of pH values (2.5−5.4). These results indicated that sunflower pectin has a high potential for producing low-calorie jellies.