Charlotte Eklund-Jonsson at the Department of Food Science said that tempe is in fact a whole-grain product with high folate content.

It's long been known that whole-grains reduce the risk of cardiovascular diseases, and that it also protects against age-related diabetes and certain forms of cancer. The B vitamin folate is the natural form of folic acid and, among other things, is necessary for normal fetal development.

"Tempe is designed for vegetarians, but also for people who want to eat less meat for environmental reasons, for example. We also had the environment in mind when we chose to base it on barley and oats, which are suitable to cultivate in Sweden and therefore do not require long transports," said Eklund-Jonsson.

This unique food is produced through fermentation with the aid of the micro fungus Rhizopus oligosporus, which originates from Indonesia, but they use soybeans as the raw material there.

But, Eklund-Jonsson developed methods to preserve the high fibre content of the cereal grains and at the same time to enhance their content of easily accessible iron. Normally these two considerations work against each other.

It was revealed that the iron uptake was doubled after a meal of barley tempe as compared to unfermented barley.