We all know the dangers of leaving cooked food out on the countertop. Our mothers taught us about this, and their mothers before them. Leaving food out for too long can cause bacteria in the food to grow to dangerous levels, and when consumed, can cause illness. Have you ever wondered why?
The bacteria in our food
Bacteria is found everywhere. Spoilage bacteria, the micro-organisms that cause food to deteriorate and develop unpleasant odors, tastes, and textures, can reproduce at an extremely high rate at certain temperatures. Bacteria grow most rapidly in between 5 deg C and 60 deg C. In this “Danger Zone,” bacteria can even double in number within a short half hour. Therefore, if not consumed within two hours, cooked food or other perishable food items should be kept in the fridge, to prevent the exponential growth of micro-organisms. Refrigeration does not mean bacteria does not grow at all – they do, but at a much slower pace. Refrigeration slows down the rate of microbial growth and biochemical reactions, but does not stop it completely, resulting in spoilage and nutrient loss after 4-7 days.
Photo: adele adams associates
What about raw food?
Similarly, if left in the “Danger Zone” for too long, raw meats become unsafe for consumption. You might think that the cooking process will rid the meats of any bacteria – this is not the case. While cooking may destroy bacteria, toxins that were produced by the bacteria are heat resistant and will not be destroyed
The good news? It is very easy to know when dairy products go bad and need to be throw out. Just watch out for discolouration, lumps, and a distinctive sour smell.
There are means to prevent milk and other dairy products from going bad so quickly. For instance, get dairy products right before payment at the till, and buy your dairy products only on days that you know you can get home ASAP to transfer the milk into the fridge.
Another easy precaution is to never drink milk directly from the container. Bacteria in the mouth can be washed back into the container.
Low temperatures slow the growth of pathogenic fungi which cause our fruit and vegetable to spoil. Thus, refrigeration is important to keep produce at their peak.
Some fruits release ethylene, a colourless and odourless gas that induces rapid ripening and softening of a lot of fruits – it would be wise to separate ethylene-producing items such as apples, mangoes, kiwis, peaches, and plus, from other produce that you do not wish to ripen as quickly or become overripe.
At such low temperatures, bacteria enter a dormant stage. Freezing keeps food safe, which is why frozen foods can keep for up to six months.
Help! Can I still eat this?
When in doubt, throw it out. If you left something out for a long period of time accidentally, and cannot smell or see anything wrong with the food item, this is the rule you should abide by. This is because bacterial contamination cannot always be discerned through visual inspection or “smell test”.
Food poisoning is not worth the risk!
Take precautions, such as limiting the amount of time your groceries spend in your car post-grocery shopping, and the amount of time cooked foods remain on the countertop before being consumed by the family. If you are a meal prepper, consider investing in portable food coolers.
Cover photo: womensday