Reliable measurements of the size distributions of starch molecules in solution: Current dilemmas and recommendations

Characterisation of the distribution functions describing size-related parameters of individual whole starch molecules in solution is important for establishing biosynthesis-processing-structure-property relations, for improvements in human and animal nutrition, and for industrial applications of starch. Current techniques for obtaining these distributions suffer from a number of problems in dissolution procedures, size separation, detection, data processing and data reporting. The need is for techniques that have been shown to give an unbiased sampling of the distribution of the starch in its original state, and which are reproducible (i.e., the same results can be obtained with a given sample in a different laboratory and different experimental set-up). The problems with current methodologies are summarized here by an IUPAC-sponsored international group of specialists in the field. Steps to resolving these problems are also discussed.