Researchers at DTU have developed a yoghurt bacterium, which can cleave lactose in a cost-effective and sustainable manner. This makes it possible to create natural sweetness in yoghurt with less added sugar.

Yoghurt without added sugar is a relatively sour experience. Often fruit or berries are added to improve taste, and sugar or sweeteners are added to increase sweetness. However, consumers are increasingly demanding natural foods with less added sugar.

To meet this demand researchers from DTU National Food Institute have developed a new and natural way to cleave the milk sugar, which relies on safe lactic acid bacteria. The developed lactic acid bacteria create natural sweetness in the yoghurt, thus reducing the need for added sugar.

Lactic acid bacteria with lactase can break down milk sugar

Yoghurt is fermented milk and milk naturally contains around 50 grams of sugar (lactose) per liter. Milk sugar is characterized by its low sweetness, but by breaking down lactose with enzymes, more sweet sugars (glucose and galactose) are released. By breaking down 70 percent of the lactose in milk, the sweetness can be increased which corresponds to 20 grams per liter of regular sugar.

Commercially available lactase enzymes currently used for breaking down lactose in milk products are made using microorganisms, which involves, a tedious and costly purification process. Furthermore, transportation from the manufacturer site to the dairy adds to the costs.

With the solution that the DTU researchers have developed, the lactic acid bacteria-based lactase can be grown and used directly at the dairy, and in the milk that ends up being yogurt. In this way, the costs for purchasing the lactase and transportation are reduced, 

The solution has been tested by a large Danish dairy.

For more information on the ability of lactic acid bacteria to convert lactose. Read the scientific article Consolidated Bioprocessing in a Dairy Setting─Concurrent Yoghurt Fermentation and Lactose Hydrolysis without Using Lactase Enzymes in the Journal of Agricultural and Food Chemistry.