University of São Paulo: USP research shows kitchen hygiene errors that put health at risk

According to the World Health Organization (WHO), every year about 600 million individuals in the world fall ill and 420,000 die from foodborne illnesses (FDA). In Brazil, between 2000 and 2018, 247,570 cases of DTA were officially registered, with 195 deaths, according to data from the Ministry of Health. And what was the main source of the contamination identified by the study? The kitchen of the house itself.

In light of these data, researchers at the Food Research Center, also known as the Food Research Center (FoRC), of the Faculty of Pharmaceutical Sciences (FCF) at USP, carried out a study to analyze hygiene habits and practices related to hygiene, handling and food storage in Brazilian homes. The results show that a significant portion of the population adopts inadequate measures. Therefore, it is more exposed to DTA. Made with 5 thousand people from all Brazilian states (mostly women between 25 and 35 years old and with income between 4 and 10 minimum wages), the research also verified the temperatures of the refrigerators of 216 homes in the State of São Paulo.

About 46.3% of participants said they used to wash meat in the kitchen sink, 24.1% usually consume undercooked meat and 17.4% consume raw or undercooked eggs in homemade mayonnaise and other dishes. “Washing meat, especially chicken, in the kitchen sink can spread potential pathogens into the environment, representing a risky practice”, explains the research coordinator, Uelinton Manoel Pinto, a professor at the FCF and a member of the FoRC.

According to him, the consumption of undercooked or raw animal foods also poses a microbiological risk, as it is recommended to cook the food at a minimum temperature of 74°C to ensure the inactivation of pathogens that may be present in the raw product. “Remembering that not every raw animal product contains pathogenic microorganisms, but there is this risk and proper cooking ensures that these microorganisms are eliminated or reduced to safe levels.”


Regarding vegetable cleaning practices, 31.3% usually do the cleaning only with running water and 18.8% with running water and vinegar. For fruit cleaning, 35.7% use only running water and 22.7% use running water and detergent. “For the safe cleaning of vegetables, legumes and fruits that will be eaten raw, the recommendation is to wash them with running water and use a chlorinated solution with a minimum contact time of 10 minutes, followed by rinsing again in running water”, he adds. The percentage of people using chlorinated water in the study was 37.7% (for vegetables) and 28.5% (for fruits). It is noteworthy that vegetables that will be cooked or fruits that will be consumed without the skin do not need to undergo disinfection in a chlorinated solution.

Refrigeration care
When shopping in supermarkets, most participants (81%) do not use thermal bags to transport refrigerated or frozen food to their homes. “In a country like Brazil, where temperatures easily reach 30°C in several cities throughout the year, it is essential that perishable products are transported in appropriate conditions, inside a thermal bag”, highlights Jessica Finger, nutritionist and researcher who conducted the research, which also had the involvement of a scientific initiation student, Guilherme Silva, who was studying Nutrition at USP.

Regarding food leftovers, 11.2% of the participants reported storing them in the refrigerator more than two hours after preparation, which represents a risk to food safety. “It is not recommended to leave food ready for more than two hours without refrigeration, as the room temperature favors microbial growth in these foods. This is one of the main practices responsible for foodborne disease outbreaks,” the researchers add.

It was also evident that it was common among the participants to thaw food at room temperature (39.5%) or inside a container with water (16.9%), which is also not suitable, since the food must be kept at a safe temperature during defrosting , which can be done in the refrigerator or in the microwave.

meat storage
About the storage of meat in the refrigerator, most participants (57.2%) reported storing the meat in the package that contains the product. This practice is questionable, since it is necessary to use a suitable container to avoid dripping of meat juice and contamination of other foods stored in the refrigerator.

The good news is that, in relation to the temperature of refrigerators, of the 1,944 records collected, 91% were within the recommended temperature range, from 0 to 10°C. This data is important, as it can be used in modeling studies to predict the multiplication of microorganisms in refrigerated foods.

The results show that in the context of hygiene, handling and food storage practices, there are certain actions performed inappropriately by a significant portion of the interviewees. Thus, an educational material was created as a way of providing guidance on the correct way to store food in the refrigerator.