Lactic bacteria fermentation for reducing the need for additives

VTT has developed a method whereby the use of additives in bread can be reduced significantly. At the same time, the taste and lightness of wheat bread made using sourdough, and keeping it soft without chemical additives, can be greatly improved.

The method is based on lactic bacteria, which produce hydrocolloids during the sourdough fermentation and which are useful in terms of baking technology. VTT identified the useful lactic bacteria in a survey in which over 100 cereal and food-based microbes were screened. Corresponding safe microbes, i.e. starters, are used in making yoghurt and sour whole milk, for instance.

Baking tests demonstrated that the hydrocolloids produced in sourdough facilitated the mechanical processability of the dough, improved the shelf life of wheat bread and increased its volume. The quality of the bread was even better than that of ordinary leavened bread: the taste was mild and there was no strong pungeant taste typical of bread made from sourdough.

Starters are used in the production of foods in which fermentation is one of the manufacturing stages. They offer a wealth of opportunities for shaping the structure, taste, healthiness and safety of the product. VTT’s research focused on starter populations that under suitable conditions generate hydrocolloids, and saccharates that gel, i.e. exo-polysaccharides. These are used as food coagulants and emulsifiers, sources of fibre, fat substitutes and bread improvers, for example. Their use is indicated by an E code on packages.

The production of hydrocolloids in the sourdough improves the already known positive effects of sourdough fermentation in baking. The technology offers opportunities for making increasingly organic bread, enabling the use of E-coded additives, such as refined hydrocolloids, to be reduced considerably or replaced altogether.

Even the use of ordinary sourdough usually improves the nutritional qualities of wheat bread e.g. by slowing down the digestion of wheat bread (low glycaemic index) and raising bread folate concentrations. The production of hydrocolloids in the sourdough makes it possible to greatly enhance the health-promoting effects of sourdough.

The technology also offers opportunities for producing ingredients for making new types of cereal products and foods. In addition to bakeries, the technology can be utilised by starter producers and other food industries.

The new technology was generated in a project entitled Tailor-Made Sourdough Fermentation for the Improvement of the Structural and Nutritional Properties of Cereal Products, which was conducted together with the University of Helsinki and the Finnish bakery industry. The main financiers were the Finnish Funding Agency for Technology and Innovation Tekes, and VTT.

Additional information:

VTT Technical Research Centre of Finland
Senior Research Scientist
Kati Katina
tel. 020 722 5184
kati.katina@vtt.fi
Further information on VTT:
Sakari Sohlberg
Chief Information Officer
Tel. 020 722 6744
sakari.sohlberg@vtt.fi