Accurate Characterisation of Complex Biopolymers

Recent work published by experts from Viscotek, a Malvern company, showcases the TDAmax gel permeation/size exclusion chromatography (GPC/SEC) system as an information-rich, time-efficient analytical solution for the comprehensive characterisation of complex food ingredients and additives based on polysaccharides. The Viscotek TDAmax sets the benchmark for GPC/SEC, with a fully integrated triple detector array that includes a revolutionary low angle light scattering detector (LALS), four capillary differential viscometer and refractive index detector. The work by Dr Gerhard Heinzmann and Dr Bernd Tartsch is detailed in a paper ‘Alginates, Chitosanes and Xanthans – Characterisation of Food Ingredients by GPC/SEC with Triple Detection’, published in AgroFOOD Industry Hi-tech (Vol 20 No. 4, 2009).

Using GPC/SEC, passing a sample through a series of carefully specified packed columns separates it on the basis of hydrodynamic size. Single or multiple detectors analyse the resulting fractions. The design and selection of the detectors dictates how much information can be gathered during each experiment. The TDAmax detector array provides absolute molecular weight without extrapolation or correction, molecular size, and intrinsic viscosity, as well as information on structure, conformation, aggregation and branching. Adding an additional UV/Vis detector, creates an integrated tetra detector array ideal for copolymer characterisation.

The performance characteristics of a range of food ingredients depend on their molecular weight and structure. It is also possible that low molecular weight fractions in some ingredients may even be harmful to human

health. It is important therefore to confirm that these have been removed. Many food ingredients have large molecular sizes, however, and this can present a challenge in accurately determining molecular weight distribution. The research detailed in the paper shows that the TDAmax can meet this analytical challenge and that it provides accurate and detailed information.