The 9 most common hygiene mistakes in the kitchen that are a health risk

Every year, 600 million people get sick and 420,000 die from foodborne illnesses. The most common causes are bacteria, which proliferate in poorly preserved or expired foods. They can cause more serious gastrointestinal infections, which in some individuals progress to very intense vomiting, diarrhea, dehydration.

This global data, compiled through the WHO (World Health Organization), have always drawn the attention of microbiology professor Uelinton Pinto, from the Food Research Center at the University of São Paulo (FoRC-USP).

The specialist then decided to assemble a team to investigate the impact of this problem in Brazil. The group’s first step was to publish a survey in 2019, which found 247,000 cases and 195 deaths related to foodborne illnesses in the country between 2000 and 2018.

“One of the things we observe is that most of the contamination happens at home”, reveals Pinto.

At the end of 2021, the team of scientists decided to understand more in depth how some common habits among Brazilians when storing and cooking food contribute to this scenario. They created an online questionnaire, which was answered by 5,000 people spread across every state in the country.

“About 46% of the participants said they wash meats in the kitchen sink, 31% only clean vegetables with running water and 24% consume undercooked meats”, he summarizes.

“These numbers show us that there is a lot of wrong thing we do in the kitchen that increases the risk of an infection”, interprets the microbiologist.

Below, you can see the most common mistakes in the hygiene of this environment and how it is possible, through simple changes, to reduce the probability of contamination. The guidelines are based on interviews conducted by BBC News Brasil and on a booklet recently published by the researchers at FoRC-USP and available for download.

1. Wash the chicken in the sink

According to the recent survey, this is the most frequent mistake among Brazilians. Many think that washing raw meat under running water removes impurities and that thin layer of goo that covers the surface of this food.

The habit is wrong and dangerous to health: the big problem is that the jet of water that comes out of the tap and hits the chicken usually splashes on everything that is close.

Imagine, for example, that next to the sink you left a dish towel and some dishes, pans and cutlery to dry. The water droplets that splashed on the chicken (and were contaminated by bacteria present in the food) can end up on these objects that, in theory, were clean.

In other words: you can put a washed spoon in your mouth, but it has received small jets of microorganisms that are harmful to the intestines.

“Chicken naturally has a certain amount of bacteria and the best way to eliminate them is through the cooking process”, teaches Pinto.

The recommendation, therefore, is not to wash the chicken before seasoning or putting it in the pan (or in the oven).

Now, if you still make a point of putting this meat in the water, try to do it very carefully, without too many splashes or nearby objects.

Cooking meat and eggs well, by the way, is another sensitive point here. Ideally, the core of the food should reach a temperature of at least 70°C. This ensures that most of the microorganisms have been eliminated.

One way to observe this is to use specific thermometers for cooking, or check the eye even if the center of the meat is no longer red or raw.

2. Use only water to sanitize vegetables that will be eaten raw

Here’s another common mistake in Brazilian homes: just putting a little water on fruits, vegetables and vegetables eaten raw and unpeeled, as is the case with tomatoes, lettuce and apples.

Even though this surface cleaning helps to remove larger impurities, it is not able to completely eliminate the microorganisms that accumulate on the surface of these foods.

The recommendation is to immerse them in a basin that has a mixture of water and sodium hypochlorite for about 15 minutes. Then, simply wash in running water and dry before storing in the pantry or refrigerator, depending on the food.

“For every liter of water, a tablespoon of hypochlorite should be added”, says Pinto.

You can find this product for sale at street markets, supermarkets, pharmacies and hortifrutis. It is also available free of charge at some health centers.

Another option here is regular bleach. In this case, always read the label carefully — to sanitize food, never use options that contain substances other than hypochlorite itself. Other ingredients that may appear in bleach formulations, such as bleach, can be toxic if consumed.

This cleansing rite does not need to be strictly followed in vegetables that are peeled and cooked, such as potatoes and cassava. The fire itself will already eliminate potentially harmful microorganisms.

3. Do not clean your hands before handling food.

Now, it’s no use having clean food if the hands you use to handle it are dirty.

In this case, pathogens that have ended up on nails and fingers can “jump” into the food, in a process that experts call cross-contamination.

Before starting any recipe (or simply picking up an apple to eat), it’s important to wash your hands with soap and water.

If you don’t have a sink nearby, alcohol gel can be a great substitute for doing this basic hygiene before any meal.

4. Use the same utensils for raw and cooked ingredients

Speaking of cross-contamination, imagine the risk you run when cutting raw meat and then using the same board and knife to detach the leaves from a lettuce.

The microorganisms that were in the meat can pass directly to the vegetables, which will be eaten raw in a salad.

“It is also important to always wash your hands after handling any raw food and, subsequently, to handle something that is already cooked or ready to eat”, adds microbiology professor Mariza Landgraf, from FoRC and from the Faculty of Pharmaceutical Sciences at USP, which also collaborated in the creation of the booklet.

5. Wait for the food to cool before putting it in the fridge

Each microorganism has an ideal temperature to multiply. Some bacteria, for example, replicate faster at 25°C. Others prefer 30, 35ºC and so on.

This explanation helps us understand why waiting for food to cool down before storing it in the fridge is not a good idea.

If, after a meal, leftovers sit in the sink or on top of the stovetop for a long time, this can present the perfect opportunity for some bacteria to multiply there.

The temperature of the pan or platter drops gradually after the stove or oven is turned off, until it reaches the ideal parameters for these microscopic beings to proliferate.

If the food goes straight to the refrigerator, the lower temperature prevents the accelerated reproduction of pathogens.

Landgraf says that this habit of letting food cool at room temperature comes from the past, when refrigerators were less efficient and putting something hot inside them even represented an extra expense of electricity.

“With the evolution of these appliances, this is no longer as serious a problem as before”, compares the expert.

6. Not placing food in the most appropriate place in the refrigerator

Top shelves, drawers, compartments in the door… The temperature can vary considerably according to each space in the appliance.

And this, once again, can influence the multiplication of microorganisms — fresh foods or foods that have already been cooked need to be more protected in the cold, while preserves, drinks and seasonings do not need such low temperatures.

That is why the manufacturers of refrigerators and the FoRC-USP booklet recommend that people place the products in the most appropriate places, as you can see in the following list:

• First shelf (the highest): egg, yogurt, milk and dairy products;
• Second shelf (middle): leftovers;
• Third shelf (the bottom one, on top of the drawer): food in the thawing process;
• Drawer: vegetables, vegetables and fruits;
• Port: drinks, spices, jellies, preserves, juice and water.

It is also worth keeping an eye on how long some foods should be stored. After that, they usually spoil and can even compromise the quality of the other products stored there:

• Fish, meat and cold cuts: 3 days;
• Sauces: 20 to 30 days;
• Leftovers: 1 to 2 days;
• Fruits and vegetables: 3 to 7 days;
• Milk: 2 to 5 days;
• Bakery and confectionery products: 5 days;
• Eggs: 7 days.

7. Leave meat in unsealed packaging

Let it be clear: the refrigerator does not completely prevent the multiplication process of microorganisms. They’ll still be there — and naturally they’re in food — but they’ll take much longer to grow and create colonies.

And one of the biggest risks in this colder environment is in the way we store raw meats.

They usually come from butchers and supermarkets in styrofoam bags or trays and plastic wrap and carry a little liquid or blood that carries bacteria.

If the package has any tears, this material can escape and spill onto other foods.

To prevent this from happening, the ideal is to change the meat in a container — placing it in a plastic or glass pot that has a lid is a good suggestion.

This is true, of course, if you are going to consume this food in the next two or three days. If it only goes to the pan after that time, the most appropriate thing is to store it in the freezer — which, by the way, is the subject of our next topic.

8. Defrost food at room temperature

The freezer is where ready-to-eat foods, raw meats, ice cream and ice are kept.

There, the temperature is so low that it practically makes the survival of microorganisms unfeasible.

The danger happens when these foods are thawed.

The FoRC-USP survey found that 39% of respondents defrost food at room temperature and 16% place the product in a bowl filled with water to speed up the process.

Both methods pose a contamination hazard: as the food is thawed, it releases water and creates the perfect environment for bacteria to thrive.

“It is always appropriate to defrost in the refrigerator. And this not only because of the microorganisms, but because of the texture of the food itself”, evaluates Landgraf.

“If it thaws little by little, it absorbs that water and doesn’t lose texture”, he adds.

Another option, if you are in a hurry, is to use the microwave, which usually has a specific function for defrosting.

9. Not cleaning the fridge from time to time

Finally, we cannot forget to periodically clean this appliance.

The objective is to eliminate stains, peels and debris that invariably fall from containers and platters. All this material can serve as food for microorganisms.

The first step is to unplug the fridge from the outlet and remove all food. Take the opportunity to check the expiration date on the packaging and throw away those that are past the point.

Remove removable parts such as shelves, drawers and compartments. Wash everything with water and neutral detergent. Then let it dry naturally.

The third step is to rub a sponge dampened with water and neutral detergent over the entire part of the refrigerator. Use a damp cloth to rinse, then dry with a clean cloth.

Finally, put all the removable parts back and return the food to the proper places.

The FoRC-USP booklet recommends that this cleaning of the refrigerator be done at least once a month.