The refrigerator at home can keep food fresh by inhibiting bacterial growth through low temperatures. However, in some cases, bacteria can still thrive in the refrigerator, leading to food spoilage and even making people sick. Experts have expressed their views on how to prevent the refrigerator from becoming a breeding ground for bacteria.
Dr. Oleksii Omelchenko, a researcher at the Quadram Institute in the UK, and Judith Evans, a professor of mechanical engineering and design at London South Bank University, wrote an article on The Conversation website stating that people rely on refrigerators to keep food fresh, but if the temperature inside the refrigerator is not suitable, it may have a counterproductive effect.
These two scholars pointed out that a study published in 2018 showed that the average temperature inside household refrigerators is 5.3 degrees Celsius, slightly higher than the recommended safe range of 0 to 5 degrees Celsius (32 to 41 degrees Fahrenheit) by experts. What is even more worrying is the frequency of temperature fluctuations. Many refrigerators exceed the safe limits for over half of their usage time.
Some refrigerators even reach temperatures as high as 15 degrees Celsius. At such temperatures, bacteria will quickly multiply, increasing the risk of food spoilage and foodborne illnesses. Part of the problem is that many refrigerators lack accurate and convenient methods to monitor their internal temperature. Most people do not know what the dial settings inside the refrigerator actually mean.
Moreover, every time people open the refrigerator door, warm air rushes in. The longer the door is open, especially when you are choosing food, the internal temperature will get closer to room temperature, creating a more suitable environment for bacteria to thrive.
These two scholars mention some methods to suppress the growth of bacteria in the refrigerator, as follows:
• Minimize the number of times the door is opened – Do not leave the refrigerator door open while taking out food.
• Clean the seal of the refrigerator door regularly – Check for mold or dirt every few months, and make sure the seal is tight.
• Adjust the temperature timely – Although many refrigerators are equipped with built-in sensors, it usually reflects the temperature at a single point, and research shows that 68% of households never adjust the temperature setting. You can place a few stick-on thermometers in different areas inside the refrigerator. If the temperature often exceeds 5 degrees Celsius, then you should adjust the temperature.
• Pay attention to the placement of food – The temperature in different areas of the refrigerator varies. The coldest place is usually at the back, while the hottest place is on the door. This means that perishable items like milk or raw meat are best stored at the back, not on the door. Butter or carbonated drinks are suitable for the door.
• Avoid overloading with food – Keep the refrigerator at about 75% capacity so that cold air can circulate properly. Foods like nuts, tomatoes, peppers, potatoes, and honey do not need to be refrigerated; you can store them in a cool, dry cabinet to save space in the refrigerator.
• Temperature is not the only issue to be concerned about – Even in refrigerators with good cooling functions, pathogens may still be present, and these pathogens are likely to be introduced through previously contaminated food or packaging. While low temperatures can inhibit the growth of many bacteria, some bacteria (such as Listeria) can survive and even multiply in low temperatures. Listeria is particularly dangerous for pregnant women and the elderly.
To reduce the risk of getting sick from Listeria infection, the UK government provides the following recommendations:
• Food that needs to be refrigerated should be placed in the refrigerator immediately after purchase and taken out only when ready to be consumed.
• Ready-to-eat foods should be consumed within 4 hours after being taken out of the refrigerator.
• Make sure to consume, cook, or freeze food before the expiration date. Foods that are past their expiration date may look and smell fine, but they may not be safe and can make you sick. You cannot see, smell, or taste bacteria that can cause foodborne illnesses.
• Follow the storage instructions provided on the food labels, including opened foods. If there are no instructions, consume opened foods within two days.
• Keep raw and ready-to-eat foods separated to avoid cross-contamination.
• Follow the cooking instructions on the packaging and cook or reheat food (including frozen vegetables) until they are thoroughly heated.
• Wash hands with soap and water frequently before, during, and after preparing meals.
In conclusion, improving the habits of using the refrigerator can keep food fresh for a longer time, make the refrigerator work more efficiently, and most importantly, protect your health and the health of your family.