Cross contamination happens when bacteria can move from one product to another, which will contaminate the foods. This is typically done by improper cleaning of cutting boards, knives, work surfaces, hands and anything else that can come in contact with raw food. Even storing foods wrong in you refrigerator can lead to cross contamination which can then lead to a foodborne illness, commonly known as food poisoning.
Please note, I am not a doctor, I do not even play one on TV. I merely have a good amount of experience in the industry, and a good knowledge of first aid. I am not trying to diagnose anything here, and if your body is doing something it shouldn’t do, go to a Doctor, please.
WHAT IS IT
Most times you get the “24 hour flu” you have actually had some sort of gastro-intestinal distress due to something you ate. Food generally takes quite a while to get through your system, and it can effect different people’s systems completely different. A piece of chicken that may not have been cooked to 165 degrees may cause one person to have issues, while someone with a healthier immune system will show no signs or symptoms.
From what I witness in kitchens at all levels of the business is pretty good sanitation (it’s what we call the whole of food safety in the biz), and if there is a break down, it is usually in this area. Speed and familiarity breed complacency, and as a chef and manager, it is a constant battle.
WHO’S AT RISK?
The people most at risk from foods that have been contaminated are what we call the high risk groups. These are very young children, Individuals with compromised immune systems, the elderly, and pregnant women. When ever we serve a demographic that contains these groups, we have to be even more careful because the effect of an illness can be much more than a bit of gastro-intestinal distress. This is why a hospital or elderly care facility are managed much differently than a basic restaurant.
IS IT ALL FOODS?
Well, in a short answer, yes. Foods that provide the best atmosphere for bacterial growth, meaning they have the best acidity, moisture, temperature, proteins and oxygen (in aerobic bacterium) available. These tend to be meats for the most part.
Recently, however, we have found that some bacteria are hiding in less conspicuous places, like the husk of a melon, or the stems of green onions, bean sprouts and even tomatoes caused a scare just a few years ago. We have a list of food we call “Potentially Hazardous Foods” that we use as a guideline, and it is always growing. (Look for more on this in a future article.)
HOW CAN YOU PREVENT IT
So now that we know what we are looking for, let’s set up a way to prevent it, and we will work on the three main areas that this can cause cross contamination to occur.
The surfaces we use are hugely important, and have a great impact on food safety. How we solve this in a professional kitchen is in a couple of ways. First, we always have sanitation solutions near our work areas to wipe them down periodically and when we switch products. Cutting boards are used for one thing then sent to be cleaned. It has become fashionable to use different cutting board colors for different foods, Red=meat, Blue=fish, Yellow=chicken, White=dairy, Tan=cooked foods, and Green=Produce. You can now buy sets that contain all of these for your home, but they do no good if you don’t use them!
Next is plan your food preparation. I cut all my veg first, set aside, then I will cut my meats, and I will change cutting boards in between. I never just “rinse” a board and put it back into use. Wipe it with a sanitizing solution and let it air dry completely before use again. Do this on all surfaces that some in contact with these foods. Knives, tools, gloves, and pans.
Storage is a key part of the equation as it can have an effect we never thought of. In restaurants we teach that the higher the final cooking temperature, the lower in the storage area (refrigerator) that product should go. This means, of beef is below chicken, and juice containing Salmonella drip into the beef, then we cook it to medium, 135 degrees), it will not reach the temperature required to kill Salmonella, which is over 160. Reverse the locations and we don’t have that issue.
I hate my “crisper” drawers in my fridge because whoever designed them knows NOTHING about food safety, which is ridiculous in my opinion. Why on Earth would you put raw vegetables on the BOTTOM of your fridge when most of the time they will never be cooked!? That is just begging for food poisoning. PLEASE, if you learn one thing today, PUT MEATS AND ESPECIALLY CHICKEN AT THE BOTTOM OF YOUR FRIDGE! On that note, I think my next act is to write these people who make refrigerators and let them in on this.
On a similar note, you remember when we were young, we had two types of moms, ones that would buy the dented can on special, and sometimes with no label, and the one that would stay away. Botulism is a bacteria that can grow anaerobically, that is to say, in the lack of Oxygen. Usually dented or swollen cans are a sign that there is growth and the resulting gas is what is pressing out on the can. This is bad. Never use a dented or swollen can.
Last, I like to call manipulation. This is the actual food handler, YOU, causing the contamination. This can be something as simple as not washing your hands, or dripping juice from one product over another, or even wiping your hand on a surface that has not been sanitized. Make sure you wash your hands frequently, and especially when you change what you are working with. I even go as far as to not only have separate boards, but I will also cut meats on one side of my stove, and veg on the other. Take this seriously, please.
STEPS TO ENSURE CONTINUED SAFETY
Develop good habits, and keep your foods safe. Start by getting those foods the lowest in your fridge, and keeping the wrapped up. Also make sure you keep you cutting boards clean, and don’t use them without proper sanitation. We will talk more on materials at another time, that can be a whole discussion, believe me! Wash your hands, and utensils frequently.
I hope you learned something reading this, and may it serve you well.