STATIC LIGHT-SCATTERING TECHNIQUE APPLIED TO PECTIN IN DILUTE-SOLUTION .2. THE EFFECTS OF CLARIFICATION

The effects of purification/clarification by ultracentrifugation and/or membrane filtration were studied by light scattering, GPC plus off-line capillary viscometry and GLC sugar analysis using a high-methoxyl citrus pectin as model substance. The emphasis of light scattering measurements was put on analysing the angular dependence of the scattered light. For that reason the interpretation of the measured data involved the use of master curves in addition to Zimm or Guinier plots. The benefits and limitations of this method of data treatment for complex systems are discussed both in theory and practice. Due to the natural heterogeneity of pectins, purification or classification modified the original sample by removing the high molecular weight and dense tail, leaving a physically and chemically heterogeneous polysaccharide.