High-risk foods are foods that we need to protect from bacteria. They are commonly involved in cases of food poisoning. This is because in the right conditions (which you will learn about later) bacteria can grow in these foods and cause food poisoning.
High-risk foods are ‘ready-to-eat’ meaning they get eaten without cooking or further cooking. The issue here is that bacteria won’t be killed by cooking. The food in question may already have been cooked (like cooked meat or cooked meat products) or served without cooking like dairy products.
Bacteria need certain things to grow. And because high-risk foods have these things, this is what makes them high risk.
High-risk foods are:
- generally ready-to-eat (meaning if they get contaminated with bacteria, the bacteria won’t be killed by a cooking stage).
- moist because bacteria need moisture to grow
- they’re high in protein because bacteria prefer protein-based foods.
Although, it is worth noting that cooked rice, pasta and potato dishes are considered high-risk, even though they’re not particularly high in protein.
The key point here is that high-risk foods need strict time and temperature control to stop bacteria from being able to grow. They also need to be protected from contamination in the first place.
Why is a raw chicken (or any raw meat!) not high-risk?
After all, it’s high in protein and moist?
The reason is because it’s not ‘ready to eat’. It’s going to be cooked. Raw foods such as raw poultry and raw meat are generally contaminated with a large number of bacteria anyway and it’s the cooking stage that kills the bacteria. If they are perishable, they should be kept chilled, but must be stored away from high-risk and ready-to-eat foods. They should also be cooked thoroughly to kill bacteria.
Low-risk foods rarely cause food poisoning and they don’t need temperature control because they don’t support the growth of bacteria. Let’s look at some examples of low-risk foods and the reasons why they’re low risk.
- Dried products such as breads, biscuits, dried rice or pasta, crisps etc. They’re low risk because there’s no moisture. And bacteria need moisture to grow. That’s why these foods can be stored at ambient temperature. Once you add liquid to dried foods (i.e. powdered milk) the food becomes high-risk.
- Products that are high in sugar such as sweets, chocolate and jams are low risk because there’s no moisture (it’s locked up in the sugar). This means the water activity or available water is low.
- Acidic products like pickled foods. These don’t normally require refrigeration until after opening. Acidic products are generally low-risk because bacteria need a neutral pH to grow. This is why strong acid such as vinegar is used as a preservative.
- Unopened canned foods are low risk until they are opened and exposed to oxygen. Canned products undergo a heat treatment called the ‘Botulinum cook’ which is carried out by the manufacturer. It involves quickly heating the cans to 121°C which kills all micro-organisms including bacteria, their toxins and spores.
