Oxidized polysaccharide derivatives to find numerous uses.

Polysaccharides sourced from different plant and microbial sources are continuing to find new uses. The range of potential applications can be increased considerably by using modification or derivatization techniques. One modification approach involves oxidation.

Several oxidation strategies have been developed by scientists at TNO Voeding (Utrechtseweg 48, 3704 HE Zeist, PO Box 360, 3700 AJ Zeist, The Netherlands). Several chemical routes have been developed and optimized, leading to a broad range of oxidized carbohydrate products.

Researchers have been able to efficiently regenerate oxidation reagents and create halogen-free oxidation processes. Purely chemical production processes are acceptable when nonfood applications are sought, but they often present a major drawback with respect to food applications. The focus of TNO research has been shifting toward enzymatic or chemoenzymatic oxidation pathways, offering a way to develop synthetic routes to food-grade products.

The range of potential applications for modified polysaccharides and their derivatives is very broad. The controlled introduction of carboxylic groups is instrumental in enhancing metal-sequestering capacity, water-binding capacity (thickening and gelling) and buffering capacity. The presence of aldehyde groups in carbohydrate derivatives leads to the formation of temporary crosslinks with other biopolymers. The stability of these crosslinks can be controlled by varying the pH and temperature, which makes possible the controlled structuring of food matrices.

Flavors, fragrances and other ingredients containing primary or phenolic hydroxyls or amino groups can be bound reversibly in (hemi-) acetals or imines, giving them pH-dependent controlled release properties. In addition, stable hybrid materials can be produced by amidation with amino acids and proteins, or protein hydrolysates and fatty amines. This approach has led to the creation of new emulsifying and thickening agents, which could yield new food ingredients that might partially replace products like gum arabic or gelatin.

Further information. H.A. van Doren; phone: [phone]; or: J. Jetten; phone: [phone]; fax: [phone].