Vitamin B2 production integrated into food fermentation

Many vitamins are produced in factories, either synthetically or with the help of microorganisms, via methods that often require complex, costly and energy-intensive purification processes. Now, researchers from the Technical University of Denmark (DTU) have successfully produced vitamin B2, also known as riboflavin, in significant quantities using a novel, cost-effective and climate-friendly method.

Vitamin B2 is important for energy production and maintaining a normal immune function, as well as iron absorption. Deficiency has wide-ranging effects, and is common in developing countries.

The researchers’ method employs a food-approved lactic acid bacterium, which can produce vitamin B2 when gently heated. As explained in the Journal of Agricultural and Food Chemistry, the team subjected the bacteria to oxidative stress, a natural pressure that compels bacteria to produce more riboflavin to protect themselves.

“We used the microorganism Lactococcus lactis, commonly known from cheese and cultured milk, to produce vitamin B2,” said Associate Professor Christian Solem from the DTU National Food Institute, who led the research. “Lactococcus thrives best at around 30°C, but we heated the bacteria to 38–39°C, which they didn’t like. Bacteria adapt to new conditions, and to defend themselves against the oxidative stress caused by the heat, they started producing vitamin B2.”

The researchers optimised the vitamin production process by adding various nutrients, achieving a production of 65 milligrams of vitamin B2 per litre of fermented substrate — nearly 60 times the daily human requirement for the vitamin. As noted by Solem, “The method allows for food to be fortified with vitamin B2 in an easy way; for example, during the production of yoghurt or sourdough.”

The method differs from existing technologies by being natural — without genetic modification — and consuming less energy and fewer chemicals compared to traditional synthetic vitamin production. Fortification only requires basic fermentation tools, which are already common in many households.

The method is notable for integrating vitamin production into the food fermentation process, which is already common in many developing countries as a way to extend shelf life. By using riboflavin-producing bacteria in food production, local manufacturers could improve the nutritional value of traditional foods economically, enhancing public health while reducing environmental impact.

“It would be ideal to package these B2-producing lactic acid bacteria as a starter culture that can be added to foods like milk, maize or cassava for fermentation,” Solem said. “When these foods are fermented using the starter culture, which includes specially selected lactic acid bacteria along with traditional ones, they automatically produce riboflavin while maintaining the traditional flavour and texture of the food.”

The method could potentially be expanded to produce other essential vitamins and nutrients, such as folic acid (B9) and vitamin B12, which are often lacking in plant-based diets. It could also be applied to various food types, including sauerkraut.

Image caption: Christian Solem in the laboratory at DTU National Food Institute. Image credit: Lene Hundborg Koss.