What is Cultured Wheat?
Cultured wheat is a natural preservative made from the fermentation of wheat flour with Propionibacterium freudenreichii. Sequential fermentation with Lactobacillus delbrueckii was also investigated to enhance the growth of P. freudenreichii in wheat flour medium and to produce enough propionate 1. By preventing the growth of unwanted bacteria, yeasts and molds, cultured wheat can replace chemical preservatives like sorbates and benzoates for a clean label alternative.
P. freudenreichii is best known for its role in the creation of Swiss Cheese. They are commonly found in milk and dairy products and have a long history of safe use in food.
The protective effect of P. freudenreichii is based on active compounds, such as propionic, acetic and 3- phenyllactic acids2-3, as well as bacteriocins4. Different bacterial resistance to propionate may be because by the different abilities of certain microorganisms that metabolizes its subinhibitory concentrations. The mode of suppressive action of propionate at neutral pH resulted in propionates retarding the growth of Aspergillus nidulans. This mechanism at work involves glucose, due to inhibition of certain coenzyme A – a dependent enzyme by its intracellular derivative propionyl-CoA5.
By using cultured wheat, it is possible to make products that are vegan, kosher and all natural while maintaining a product that is palatable. This is especially true because the lactic acid does not interfere with the functions of yeast in bread, allowing the bread to rise normally. Cultured wheat has not been shown to dramatically alter texture, flavor or color in baked goods. Yet it has been shown to lengthen shelf life just as much as other more widely used preservatives in bread. As a result, it is growing in popularity in all natural and organic products.
Besides the nutrients in flour, like carbohydrates, lipids and proteins, the combination of the exopolysaccharides produced by bacteria Weissella confusa and heteropolysaccharide produced by Propionibacterium freudenreichii fermentation has the effect of texture-building and anti-staling in bread6.
Cultured wheat fermented by Propionibacterium freudenreichii has been proved to inhibit the growth of Bacillus subtilis, Escherichia coli and some Pseudomonas species not only in acidic but also in pH neutral conditions1. The efficiency of P. freudenreichii fermented cultured wheat against Bacillus subtilis, Bacillus cereus, Pseudomonas putida growth was similar to the chemical propionate, taken in the same amount1.
Difference between cultured wheat and sourdough
Sourdough bread is prepared from a mixture of flour and water that is fermented with lactic acid bacteria (LAB), mainly with heterofermentative strains. A mixture of lactic acid and acetic acid in the final product causes a pleasant sour-tasting end product.
Sourdough also has the antibacterial and anti-mold activities due to the production of organic acids and other still unknown antibacterial substances produced from lactobacillus. Although the production process of sourdough and cultured wheat are similar, their roles are different. Sourdough is used for flavor enhancement and cultured wheat is used as a natural preservative.
- Danilova, Irina V., Hao Lee, Tatyana P. Tourova, Eugenia P. Ryzhkova, and Alexander I. Netrusov. “Propionibacterium Freudenreichii Strains As Antibacterial Agents At Neutral pH And Their Production On Food-Grade Media Fermented By Some Lactobacilli.” Journal of Food Safety 32.1 (2011): 48-58.
- Lind, Helena, Hans Jonsson, and Johan Schnürer. “Antifungal Effect of Dairy Propionibacteria—contribution of Organic Acids.” International Journal of Food Microbiology98.2 (2005): 157-65.
- Lind, Helena, Jã¶Rgen Sjã¶Gren, Suresh Gohil, Lennart Kenne, Johan Schnã¼Rer, and Anders Broberg. “Antifungal Compounds from Cultures of Dairy Propionibacteria Type Strains.” FEMS Microbiology Letters271.2 (2007): 310-15.
- Holo, Helge, Therese Faye, Dag Anders Brede, Trine Nilsen, Inger Ødegård, Thor Langsrud, Johanne Brendehaug, and Ingolf F. Nes. “Bacteriocins of Propionic Acid Bacteria.” Lait Le Lait82.1 (2002): 59-68.
- Brock, Matthias, and Wolfgang Buckel. “On the Mechanism of Action of the Antifungal Agent Propionate.” European Journal of Biochemistry271.15 (2004): 3227-241.
- Tinzl-Malang, Saskia Katharina, Peter Rast, Franck Grattepanche, Janice Sych, and Christophe Lacroix. “Exopolysaccharides from Co-cultures of Weissella Confusa 11GU-1 and Propionibacterium Freudenreichii JS15 Act Synergistically on Wheat Dough and Bread Texture.” International Journal of Food Microbiology214 (2015): 91-101.