Xylan, fibrillated cellulose, and lignin are wood-derived polymers that could be used for improving the texture and reducing the energy content of food products.

According to VTT Technical Research Centre of Finland, Xylan, a hemicellulose extracted from birch pulp, could be used as texture enhancer in yoghurt. Compared to conventional manufacturing techniques, VTT showed that xylan improved the smoothness of yoghurt and made the texture was also more stable: no separation of water from the yoghurt gel was observed in the tests. VTT tested xylan in yoghurt at concentrations of 1.5 and 3 %. Enzymatically hydrolysed xylan worked better at the lower concentration. In addition, xylan breaks down slowly in the in vitro colon model and, therefore, is unlikely to causes flatulence as commonly used fructans might.

Fibrillated cellulose, which is produced by wet-grinding cellulose fibers, is particularly useful for its ability to bind water at low concentration and form a web-like gel. It could be utilized as thickening and stabilizing agent for instance in fermented dairy products, such as yoghurt. In VTT’s in vitro digestion model also showed that fibrillated cellulose binds free bile acids, which is an indication of potential cholesterol lowering effect in the human body.

Lignin has surface-active properties and could be utilized to prepare emulsions and foams with improved texture and to reduce oxidation in food products. VTT found that lignin gives muffins a fluffier texture and is a surprisingly efficient substitute for whole eggs and egg yolks. Lignin also functioned as emulsifier in mayonnaise and supported juiciness in a meat product.

Some wood-derived ingredients, such as xylitol, microcrystalline cellulose, and carboxymethylcellulose have been used as food additives already for decades.

• VTT Technical Research Centre of Finland Ltd., Espoo, Finland