Bacteria make vitamin B12 in beer by-product – Online resource

If it were up to Hermien van Bokhorst-van de Veen and her colleagues from Wageningen Food & Biobased Research, we renewed part of the product left over from beer production by enriching it with vitamin B12.

“In Europe, around six to eight million tonnes of spent grain is produced annually as a residual stream from our beer production. This is now often used to make animal feed. It is good that we do not throw it away or burn it, but it would be better if we could process this residual flow – from a product made especially for people – into something valuable that people can eat too,” says Van Bokhorst. .

Non-animal source

Vitamin B12 is one of the nutrients that everyone needs. “It is essential because it plays a role in making, among other things, hemoglobin, which provides oxygen to our cells. In addition, the substance is essential for the proper functioning of our nervous system.’ This vitamin only occurs naturally in meat, fish, eggs and milk. So animal products. “Now that more and more people are giving up animal products, it’s important that we get B12 from other sources. Another source could be consumed by grain,” says Van Bokhorst.

“Our project started with a literature review and then we tested the concept on a small and larger scale,” says the researcher. Bacteria Propionibacterium freudenreichii in Priests of megaterium they were the chosen people. ‘According to the literature, they were able to produce vitamin B12 in plant material through fermentation, but no research has yet been done on spent grain.’

Fermentation

We got the result as a thick, smooth paste. We made this more manageable at first by weakening it. We then applied literature knowledge about optimal fermentation conditions. Consider, for example, acidity and temperature’, Van Bokhorst explains the process. Furthermore, the propionic acid bacterium seemed to do better than the Priests of megaterium.’

At first, they reached about 0.5 to 1 microgram of vitamin B12 per 100 grams of grain consumed. “That was a good start, but according to health advice we should take around 2.5 micrograms of B12 a day. That would mean you would have to eat a lot of whole grains to get that amount of B12 if you didn’t eat animal products. So we would prefer to produce a higher density.’ Fortunately, the researchers were still able to turn several buttons. ‘Among other things, we thinned the corn we used: we went from a slurry to a thick paste, almost as it was given. We have also increased the incubation time, oxygen availability and temperature. In a laboratory setting – with small numbers – we achieved more than twenty micrograms per hundred grams.’

Baked bread

“Finally, we also tested on a larger scale in a woodworking machine with a capacity of 12 kilos. We have millions of tonnes of grain wasted every year, so knowing just the scale of the laboratory is not enough.’ Finally, they reached more than 7 micrograms of B12 per 100 grams. It is a good starting position for our business partner who gave us the wasted bread so that we can take it over from here and increase the output. The rich fruit, for example, can be used to bake bread. A chef has even done that with the ingredients from our fermenter test.’

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