‘New’ Lactic Acid Bacteria May Make African Camel Milk Safe

A research project led by the Technical University of Denmark, DTU, has created the formula for a freeze-dried starter culture that African camel milk producers can use to make safe fermented dairy products.

Most of the world’s camels are found in East Africa, where they are a common dairy animal. Camel milk constitutes more than 9% of Africa’s total milk production. Farmers, who milk the animals, sell much of the milk as a fermented product in local markets or from roadside stalls.

The fermentation process occurs spontaneously as farmers do not have cooling facilities. Since the level of hygiene is often poor, milk also often contains disease-causing microorganisms such as E. coli and salmonella, which have a chance to multiply in warm milk.

The “new” bacteria ferment the milk and increase safety

In a research project, researchers from the National Food Institute of the Technical University of Denmark have managed to find a way to make milk safer. The research was conducted in partnership with the University of Copenhagen, food ingredient producer Chr. Hansen University and Haramaya in Ethiopia. It was funded in part by Denmark’s development cooperation program, DANIDA.

Researchers have isolated new strains of lactic acid bacteria from raw camel milk, which can be used in a starter culture that acidifies the milk and kills even large numbers of various disease-causing microorganisms in milk. To the researchers’ knowledge, this is the first time that research has shown that these bacteria can be used to make camel milk products safer to consume.

Research relay race

The research for the five-year project was carried out in part with the help of several students from the Technical University of Denmark and the University of Haramaya, who have, over time, passed on. In total, ten students from the National Food Institute have spent a semester in Ethiopia, including three Bachelor of Engineering in Food Safety and Quality, who have found the formula for a quality-controlled, lyophilized starter culture based on the bacteria.

The trio’s experiments have shown that five liters of milk can produce enough starter culture to produce half a million liters of safe, fermented camel milk. However, the researchers responsible for the camel milk project recommend that farmers treat the milk with heat to reduce the amount of disease-causing microorganisms in the milk as much as possible before adding the starter culture.

The three students, Line Kongeskov Frimann, Laura Pontoppidan and Louise Marie Matzen, found it an exciting and stimulating challenge to carry out a relevant engineering project in a cooperation between two very different universities.

Foodborne illnesses kill more often in Africa

Countries like Denmark have an effective healthcare system that can quickly help unlucky people to get sick from something they eat or drink. However, in Africa, the health care system is less robust. A foodborne illness that causes diarrhea and vomiting can quickly dehydrate the patient and, without access to medical care, the illness can be fatal.

African researchers estimate that food poisoning kills 137,000 people annually on the continent. For Haramaya University, the project is an important element in the university’s work to develop sustainable solutions and increase food security in Ethiopia.

The work on isolating strains from camel milk is described in more detail in a scientific article in the International dairy magazine entitled “Antimicrobial activity of new strains of Lactococcus lactis against Salmonella Typhimurium DT12, Escherichia coli O157: H7 VT− and Klebsiella pneumoniae in raw and pasteurized camel milk”.

First author Esben Bragason wrote the article during the last semester of his master’s course, while DTU’s research labs were closed during the spring of 2020, along with much of the rest of Denmark. The article is based on their research, which documents the antimicrobial effect of strains of bacteria.