Until recently, the sole purpose of a gluten-free claim has been to indicate the suitability of food products for people suffering from coeliac disease.
Coeliac disease is one of the most common diseases resulting from environmental (gluten) and genetic factors, affecting approximately 0.5–1% of people around the world. It is a lifelong autoimmune disease of the small intestine, caused by a reaction to gluten. Classic symptoms include gastrointestinal problems such as diarrhoea, steatorrhoea and weight loss due to malabsorption (Gujral et al., 2012).
Nowadays, gluten-free claims are no longer just attracting the attention of people suffering from coeliac disease. “Healthy” and “free from” are two of the watchwords for baked goods. Of all the “free from” claims, gluten-free is particularly relevant (Euromonitor International, 2016). While improved diagnosis facilitates confirmation of coeliac disease and results in an increased range of gluten-free products, a growing number of health-conscious people believe gluten to be fundamentally unhealthy and they, too, avoid it. Thus the tremendous rise in gluten-free products in recent years stems from the general popularity of “free from” and allergen-free products. The market has also grown as a result of “free from” consumers widening their repertoire, with almost half of those who eat or buy “free from” products saying they are likely to eat more from this range over the coming year. Although the “free from” market is thought to be slowing down, individual eating patterns will become the norm, offering technological hurdles to producers who have to deal with the challenge in order to cater to this trend (Mintel, 2014).
The challenge of developing gluten-free breads
Conventional bread baking commonly uses flours like wheat, rye, triticale, and barley, which contain two different types of naturally-occurring protein fractions: glutenin and gliadin. Glutenin is responsible for the elasticity of dough, while gliadin contributes to its viscosity. Hydration of these proteins commences when water is added. The two
proteins begin to stick to each other through the formation of chemical bonds. This causes the development of a strong yet very elastic protein complex known as a gluten network. This gluten network contributes to the supporting structure of the loaf and retains the carbon dioxide in the dough. The high elasticity of the gluten network and the ability to trap the gas enables the dough to rise and expand.
Unfortunately, gluten-free flours such as corn or rice flour are not able to provide the same elastic matrix needed for the typical structure and textures associated with bread. Therefore, if the gluten network is missing, additional ingredients are needed to mimic the function of gluten.
Gluten-free breads baked without the addition of such ingredients tend to be very dense with a crumbly structure. Moreover, the taste and the overall quality are often perceived as inferior, and gluten-free breads tend to go stale very quickly (Demirkesen et al., 2013).
Jungbunzlauer offers xanthan gum as a solution to these problems. Xanthan gum can be used as the sole hydrocolloid in gluten-free recipes, but also shows outstanding performance in combination with other hydrocolloids.
Xanthan Gum – a fermentation-based hydrocolloid in gluten-free bread
Xanthan gum is a polysaccharide with extraordinary rheological behaviour. It dissolves readily in cold and hot water and forms viscous, pseudoplastic solutions. Even at low concentrations, xanthan gum solutions show a high degree of viscosity unaffected by temperature and pH variations. All of these properties make xanthan gum a very effective stabilizer and thickener. It imparts a pleasant consistency to the final product, improves sensory properties and provides long-term stability.