Beware cafe and restaurant soft drinks

Packed with vitamin C, fresh orange juice is widely regarded as a healthy drink to enjoy at breakfast or on a summer’s day.

But almost half the orange juice served in cafes and restaurants could be contaminated with dangerous bacteria such as salmonella, scientists say.

The problem is down to dirty juicers and serving jugs, said researchers from the University of Valencia, who analysed 190 batches of juice from various cafes, restaurants and bars in Spain.

They called for caterers to ensure machines are thoroughly cleaned and to serve the drink immediately after squeezing.

Under EU food regulations, 43 per cent contained ‘unacceptable’ levels of enterobacteriaceae, the bacteria family which includes Salmonella and E.coli.

The scientists also found that one in ten samples contained unacceptable levels of mesophilic bacteria, which thrives at room temperature.

The problem is believed to be down to caterers squeezing a large amount of juice at one time and leaving it in stainless steel jugs where it heats up, allowing bacteria to thrive.


Salmonella was found in 0.5 per cent of the samples, and Staphylococcus aureus – which can cause unpleasant skin infections – was found in one per cent of them.

More than 80 per cent of juice kept in metal jugs contained unacceptable levels of enterobacteriaceae, compared to just a fifth of juice samples served in a glass.

Study author Isabel Sospedra, whose findings were published in journal Food Control, said: ‘Some orange juice is consumed immediately after squeezing but many cases it is kept unprotected in stainless steel jugs.

‘We found that some juices that were kept in metal jugs presented unacceptable levels of enterobacteriaceae in 81 per cent of cases and in 13 per cent of cases with regards to mesophilic aerobic bacteria.

‘However, when the freshly squeezed juice is served in a glass, these percentages fall to 22 per cent and two per cent respectively.’

She added: ‘Juicers and juicing machines have a large surface area and lots of holes and cavities. This promotes microbial contamination, which is picked up by the juice as it is being prepared.

‘To ensure consumer health, we recommend that juicers are cleaned and disinfected properly. The same goes for the jugs in which the juice is stored, although its consumption is better as and when it is squeezed.’

E.coli infection link to colon cancer

People carrying a virulent strain of E.coli bacteria may be more susceptible to developing colon cancer, according to new research.

E.coli is frequently found in the colon of patients with colon cancer, and it’s already known that some strains of E.coli, such as enteropathogenic E.coli (EPEC), can attach to epithelial cells which line the colon. Scientists at the University of Edinburgh decided to investigate whether strains of E.coli such as EPEC were able to change or predispose colon cells to become cancerous.

They discovered that not only did EPEC attach to colon cells, but also injected several proteins into them. Two of the proteins were shown to interfere with the colon cells DNA repair mechanisms, causing the cellular DNA to be more susceptible to genetic mutation. This process could put the colon cells at greater risk of becoming cancerous.

When tissue samples fromcolon cancer patients were analysed, they found that 50% per cent of the tumour samples were infected with E.coli, half of which were positive for the virulent EPEC strain. No EPEC bacteria were found in tissue samples from healthy volunteers.


Lead researcher, Dr. Oliver Maddocks from the University of Edinburgh said:

“We can’t say for certain that this type of E.coli bacteria definately cause colon cancer, as it is possible these patients acquired the bug after the tumours developed.

“But our laboratory work does stongly suggest that bacteria are able to influence colon cells in a way that might predispose them to cancer, and so there is a real chance that infection could aid the development of colon tumours. We hope our findings stimulate further research to clarify the causes of this common cancer.”

Colon cancer is the second most common cancer in the UK. Each year, more than 35,000 people are diagnosed with colon cancer, and 10,000 die of the disease.

Poor food hygiene can result in an EPEC infection. Children infected with EPEC may have diarrhoea, but the bacterium can be carried in adults and children without causing any symptoms. Current estimates suggests tht between two and ten per cent of the healthy population carry EPEC.

The scientists went on to suggest that a further larger study investigating the occurrence of EPEC bacteria in colon cancer patients and healthy people should be carried out.