fast food sandwich

Food Microbiology – The Hidden Public Service

Food microbiology laboratories study microorganisms that can inhibit or contaminate food, causing food spoilage or illness in people. Although laboratories perform research on useful microorganisms used in the production of fermented foods such as cheese and yoghurt, they also perform unseen work ensuring the food we all eat is safe and free from contamination.

In this blog, we explore the unseen work done in micro labs to ensure nobody gets an upset stomach, or worse…

What Is Food Microbiology?

Generally, food microbiology is the study of microorganisms used in food production and found in contaminated products. Food safety is the major focus of food microbiology with laboratories across the UK routinely examining the foods we eat, testing them for foodborne pathogens that may cause illness.

Testing is performed on a wide variety of foods, from milk and other dairy products to ready meals and pre-packed sandwiches. Raw ingredients are also tested, and all laboratory samples come from various points in food production lines.

Why Is Food Tested In Micro Labs?

Food manufacturers and suppliers send products to micro labs to test them for various pathogens that can be harmful to human health. This is done to protect public health and meet UK safety standards on food. Of course, food manufacturers want to protect themselves from incident too.

Without food safety testing, there would be many more outbreaks of food poisoning which can put vulnerable people at risk, including pregnant women.

Foodborne illness outbreaks can make people temporarily ill – such as a case where 147 people became ill from eating cucumbers contaminated by Salmonella. But in some cases, outbreaks can be deadly; a notorious E.coli 0157 outbreak in the mid-’90s left 21 people dead and hundreds needing treatment.

man holding stomach

There are also particular risks for people in vulnerable groups from certain pathogens, for example, Listeriosis in pregnant women can cause miscarriage. Elderly people and the very young are also more vulnerable to foodborne illnesses becoming serious because of their age.

From the health risk perspective, food microbiology labs carry out a public health service by helping keep our food free from contamination. Some microbiology labs will also test drinking water, perform shelf-life testing on food products (to determine at what point food becomes unsafe to eat after it is opened/purchased), and interestingly, food adulteration tests to check foods are what they say they are on the label.

Of course, there is also a financial reason for food manufacturers to ensure their food is safe to eat – product recalls can be incredibly expensive and reputational damage from outbreaks of illness have the potential to be devastating. In serious cases there could also be fines issues, criminal charges brought, and compensation to be paid so it makes sense to ensure food is thoroughly checked before it is sold to the public.

How Is Food Tested?

Once samples of food arrive at a laboratory for testing, a wide range of laboratory equipment will be used to perform tests.

Generally, food samples need to be prepped before analysis by adding broth using a laboratory dilutor and homogenised. The solution is then put into plastic Petri dishes containing different types of growth medium, dependant on the type of pathogen being tested for. The Petri dishes are then incubated for set periods before being examined by a microbiologist or laboratory technician to determine what bacteria are present and in what quantity.

Suspected positive samples are put onto slides and microbiology stains used to further examine the samples under a microscope.

Manufacturer and public safety guidelines determine at what level a pathogen may become a concern and the laboratory will act in accordance and contact their customer who will then take appropriate action. This could involve a further investigation at the manufacturing facility, further sample testing, and in serious cases, product recalls.

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