We talk a lot about cross-contamination here at Food Poisoning Bulletin. Cross-contamination is simply transfer of pathogens from one food to another, or to a surface. It is responsible for many cases of food poisoning caused by pathogens such as E. coli and Salmonella every year in the United States. So what is cross contamination and how can you prevent it?
There are many different types of cross-contamination. It can occur while harvesting food, processing it, during transportation, while shopping, in the kitchen, and during food service.
We are mostly concerned with consumer behavior here. Direct cross-contamination occurs from food to food contact. Indirect cross-contamination occurs when bacteria are transferred from your hands or utensils from one food to another. To prevent cross-contamination, follow a few rules.
While Shopping
When you are shopping, keep raw meats, poultry, seafood, and eggs (as well as other foods discussed below) away from foods that are eaten raw, such as fruits and vegetables. And because other shoppers may not be as careful, clean the handle of the shopping basket or cart with a disposable wipe before you begin.
Bag meats, poultry, seafood, and eggs in the disposable plastic bags provided at the store. You may want to put your hand inside the bag and then pick up the item. Pull the bag over the meat, tie it off, then put it into the cart away from produce. Then wash your hands with soap and water as soon as you get home.
In the Refrigerator
It’s important that you arrange food in your refrigerator to keep it safe. Never put raw meats and poultry on shelves above produce, since juices from those items could drip down. Put the meat onto a cookie sheet with sides in the fridge to prevent any drips, or put it into a sealed container. Do this when thawing frozen meats and poultry too.
Keep eggs in their original carton and do not store in the door, which is too warm for that food item. Keep ready to eat and cooked foods away from raw food.
And store fruit and vegetables in plastic bags or containers too, to keep them from any bacteria that may be in the fridge, as well as accidental cross-contamination with other foods.
And it helps to clean your refrigerator often. Wipe up drips and clean all shelves with soapy water. Remember that pathogens, such as Listeria monocytogenes, can grow at refrigerator temperatures, so don’t get complacent.
During Food Preparation
Cross-contamination happens most often during food preparation. Begin by washing your hands, especially if you have used the bathroom or have been caring for someone who is sick. Clean countertops, especially if you have animals, with hot soapy water too.
Then, prepare raw meats, poultry, seafood, and eggs separately from fruits and vegetables. Use a separate cutting board for these items. If you don’t have more than one cutting board, wash it with hot soapy water after using it to prepare meats and poultry. Discard cutting boards that have deep grooves in them, because bacteria can thrive in those grooves and can be difficult to eradicate. Wash knives and forks after they touch raw meat.
Remember that some foods you may not think are contaminated can be. Raw sprouts, leafy greens, flour, cake mixes, soft cheese, and deli meats can be contaminated and have caused outbreaks, and should be isolated in the fridge and during food preparation just like raw meats are.
Wash your hands with soap and water every time you touch raw meats, poultry, seafood, or eggs. Studies have shown that bacteria can be transferred to refrigerator door handles, appliance dials, other foods, and other kitchen surfaces when people don’t wash their hands frequently during food preparation.
Do not reuse packaging materials that held raw meats, poultry, seafood, or eggs. Bacteria on those products can easily transfer to other foods. Wash all reusable storage containers thoroughly before you use them again.
Do not rinse poultry under the kitchen faucet. The only way to kill pathogens is to use heat – in other words, thorough cooking. Under running water, bacteria can splash around the sink, and it can actually aerosolize, spreading up to three feet away. That means it could land on other food, the countertop, utensils, appliances, and your face and hands. If you must do something to the bird before cooking, pat it dry with paper towels, then discard the towels and wash your hands.
Be especially careful when you are preparing foods such as breaded frozen stuffed chicken breasts. The breading on those products can be contaminated and can fall off and contaminate work surfaces in your kitchen. Clean any area where those foods were with hot soapy water.
When you are grilling, never put cooked foods on the platter that held the uncooked meat. Use clean utensils too. I like to use a fresh spatula after turning these foods on the grill. Use a clean fresh platter, or thoroughly wash the platter with soap and water. Any marinades, including the marinade you brushed on the food as it was grilling, should be boiled for two minutes before it is served at the table. And wash the tip of your food thermometer after you test the temperature of raw meats and poultry. Every time.
Think about using paper towels rather than cloths in the kitchen. A cloth can hold onto pathogens and transfer them to your hands or utensils.
Finally, your cellphone can be a source of bacteria. If you use it in the kitchen, mount it on something like your cabinets so you don’t touch it a lot. Clean the cellphone using approved towelettes.
During Service
Wash your hands after you finish cooking and before serving food. And make sure that everyone at the table has washed their hands too.
Wash all serving utensils plates before you eat, or make sure they are clean before you set the table.
Stay Safe
These tips aren’t meant to scare you, but are just good cooking habits to use for a lifetime. They will become ingrained into your cooking style and become habits that you will follow every time you cook and bake.
And enjoy the process. Cooking and baking are enjoyable activities and you will have more fun if your food is not only delicious, but safe to eat.
