A new, natural method for producing vitamin B2 “could be a game-changer” for low- and middle-income countries, where deficiency is common, say Danish scientists.
A team from the Technical University of Denmark (DTU) successfully produced vitamin B2 – also known as riboflavin – in significant quantities by gently heating food-approved lactic acid bacteria. Subjecting the bacteria to oxidative stress, a natural stressor, compelled them to produce more riboflavin to protect themselves.
The researchers optimised the process by adding various nutrients, achieving a production rate of 65 mg of vitamin B2 per litre of fermented substrate, which they say is nearly 60 times the daily human requirement for the vitamin.
“I think it’s beautiful that something as simple as gentle heating and lactic acid bacteria can be used to produce vitamin B2,” said lead researcher Christian Solem, associate professor at the DTU’s National Food Institute.
“The method allows for food to be fortified with vitamin B2 in an easy way – for example, during the production of yoghurt or sourdough.”
Most vitamins are produced in factories, either synthetically or with the help of microorganisms that are not approved for food use. Their production requires extensive and often complex purification processes to separate the vitamin from non-food-approved materials, which can be costly and energy-intensive.
The new method, however, provides a cost-effective and climate-friendly method for producing vitamin B2. It could potentially be expanded to produce other essential nutrients, such as folic acid (vitamin B9) and vitamin B12, which are often lacking in plant-based diets, the researchers suggested.
“We used the microorganism Lactococcus lactis, commonly known from cheese and cultured milk, to produce vitamin B2,” Solem said. “Lactococcus thrives best at around 30°C, but we heated the bacteria to 38 to 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 study, which was published in the Journal of Agricultural and Food Chemistry, was funded by the Independent Research Fund Denmark through the project Bioshuttle.
Vitamin B2, found in foods including milk, eggs, and leafy vegetables, is an essential nutrient for energy production and immune function. It also plays an important role in iron absorption.
Deficiency is most common in low- and middle-income countries in Asia and Africa, and has wide-ranging effects, causing fatigue, swollen throat, blurred vision, and depression, as well as skin problems. However, more than half of the global population consumes inadequate levels of essential micronutrients, including riboflavin.
The new method integrates the vitamin’s production into the food fermentation process, allowing for these nutrients to be produced and added locally, and enabling manufacturers to improve the nutritional value of traditional foods economically.
What’s more, it uses less energy and fewer chemicals compared with traditional synthetic vitamin production. Fortification only requires basic fermentation tools, many of which are already common in many households.
Many countries have a tradition of fermenting foods, which extends shelf life and reduces waste. Solem highlighted this as a potential avenue of application.
“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,” he 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.”
