Extraction and characterization of sunflower pectin

Chemical composition and rheological properties of sunflower pectin, including gel-point temperature (T-g) were determined. Pectin from sunflower head residues was characterized and compared with low methoxyl commercial pectins. Pectin was isolated using sodium hexametaphosphate extraction followed by either acidified alcohol (KIM) or HCl solution (LIN) precipitation. LIN pectin resulted with a higher ash content (approximate to30%). The low methoxyl pectin extracted from sunflower heads had 11% degree of esterification, high anhydrogalacturonic acid content (77-85%) and low acetyl content (2.3-2.6%) on an ash-free basis. Viscosity average molecular weight ranged from 39,500 to 52,000. Sunflower pectin formed gels at high temperatures almost instantly in the presence of calcium ions. (C) 2003 Elsevier Ltd. All rights reserved.