Quantitative NMR Assessment of Polysaccharides in Complex Food Matrices

Polysaccharides are a critical component of many food stuffs owing to their stable rheological properties. Food polysaccharides show great structural diversity. These characteristics, together with strong matrix interactions, complicate the quantitative assessment of polysaccharides in complex product formulations. Most current analytical approaches rely on qualitative identification of polysaccharides and quantification based on monosaccharide analysis. NMR for example has typically been applied for qualitative purposes but recently progress has been made in semi-quantification. However employing this technique for the absolute quantitative assessment polysaccharides is less straightforward. This is primarily due to broadened and overlapping lineshapes, which compromise NMR signal integration. In this chapter the authors describe the hybrid NMR approach that they have developed in response to this problem for quantifying polysaccharides in food products. They demonstrate that through combining information on identified polysaccharides and monosaccharide composition it is possible to achieve absolute quantification of polysaccharides in full product formulations in the w/w% range with 10% precision.