Making camel milk 'safer': Researchers combat E. coli and salmonella with new lactic acid bacteria
In Africa, naturally fermented camel milk sold by farmers at local markets often contain disease-causing microorganisms. Now, researchers have isolated ‘new’ strains of lactic acid bacteria they say can make the milk safer.
While camel milk is somewhat of a rarity in Europe, the same cannot be said of Africa, where camels are considered a common dairy animal. Indeed, up to 9% of Africa’s total milk production comes from camels.
Compared to cow’s milk, camel milk is slightly lower in total fat and saturated fat, but on par with cow’s milk total calorie and protein content. Camel milk is also considered a source of iron and vitamin C.
Such nutritional benefits, however, can be compromised in Africa when disease-causing microorganisms contaminate the milk. This occurs when farmers, who may have poor hygiene, are unable to refrigerate fresh camel milk.
The milk naturally ferments, and when it is sold by farmers at roadside stalls or in local markets, it is often already contaminated with pathogens such as E. coli or salmonella.
A research project led by the Technical University of Denmark (DTU) and assisted by the University of Copenhagen and Haramaya University of Ethiopia is working to solve this issue, by making camel milk ‘safer’.
Danish ingredients supplier Chr. Hansen also partnered with the researchers, providing ingredients for several application trials. The Danish International Development Agency (DANIDA) contributed funding to the project.Isolating ‘new’ strains of lactic acid bacteria
The researchers successfully identified new strains of lactic acid bacteria from raw camel milk. Using these bacteria as a starter culture, they were then able to acidify the milk and kill ‘large amounts’ of various disease-causing microorganisms in the process.
Five litres of milk was found to make enough starter culture to produce half a million litres of safe, fermented camel milk, they noted. However, they recommend that farmers heat-treat the milk to kill as many disease-causing microorganisms as possible before adding the starter culture.
To their knowledge, this is the first time research has shown these bacteria can be used to make camel milk products safer to digest.
“Starter bacteria multiply and grow in the milk,” DTU professor and lead author, Egon Bech Hansen, explained. “The benefit of using a defined starter culture is that you determine which bacteria will dominate the fermentation. The product quality will become more predictable and show less batch-to-batch variation.”