Tip Friday Health Facts About Onions
Last week I gave some tips on How Not To Cry When Cutting Onions.
Today I wanted to touch on some health facts involving cut onions.
Is it ok to use leftover onions?
Conditions that should be avoided by persons with a compromised immune system is something I have been becoming familiar with.
Reading that onions, once cut can be harmful, I researched this information.
I found an article by Dr. Ruth MacDonald, Chair and Professor of the Department of Food Science & Human Nutrition, Iowa State University, to get the facts!
When you cut a vegetable the cell walls are disrupted.
Water and fluids are released and these may contain nutrients that enhance bacterial growth.
So if there are bacteria present the cut surface will provide an enriched environment for more growth.
Placing the onion or vegetable in the refrigerator will typically slow down the bacterial growth, but does not inhibit it completely (and some bacteria actually grow very well at refrigeration temperatures).
When you pick up the vegetable, bacteria from your hands will be transferred to the surface of the vegetable.
Or when you place it on the counter or cut it with a knife, bacteria can be transferred from the counter or the knife onto the vegetable.
So what should one do to prevent illness from vegetables?
- At the store:
Select intact vegetables that do not have soft spots or bruises and handle them gently.
- At home:
Wash the vegetables with cool water, use a gentle brush if you want – and dry. - Store them in a cool and dry location, or in the refrigerator.
- When you handle vegetables, wash your hands first, use clean utensils and cutting boards, and avoid cross contamination especially with raw meats or eggs.
- Immediately wrap leftovers in plastic or place in sealed containers to prevent moisture loss and store in the refrigerator – use within 2 days. If the leftovers look mushy, have a cloudy fluid around them, feel slimy or have an odor – throw them out!
Do you know the best type of onion to use for your dish?
Sweet Onions are best for frying. They are used for onion rings, gratins and roasted vegetables.
Red Onions are best for eating raw. They are used in guacamole, pickled onions, salads and sandwiches.
White Onions are the crunchiest and have the sharpest zing. They are used for salsas, chutney and stir fry.
Yellow Onions are the best all around cooking onion. They are used for meat roasts, braised meat dishes, sauces, soups and stews.
Shallots are milder and have a more subtle taste. They are used for vinaigrettes, egg casseroles and garnishes.
Most images in my Tip Friday Series use free stock photos.
This article is part of the Tips That Help in the Kitchen Series, Tip Friday.
I am Marilyn Lesniak. Writer, Photographer and Chief Bottle Washer behind the scenes at Marilyn's Treats. Follow me to my kitchen. 
Marilyn these are some great tips. Years ago I was researching onion as a remedy for the common cold and I had seen glimpses of articles saying that you shouldn’t use an onion after it’s been cut. But I never followed up on it. We typically use an entire onion when we cook, but there are times when we put it away for a few days, in the refrigerator, in tupperware. Now I will keep a much better eye on it, especially as I have an autoimmune disease. I love coming here, I always get great tips and ideas. Thanks for sharing this I will be more careful from here on out.
I was shocked Niki. My husband and I both have health problems. When we both got sick is when the Dr asked about food storage. Congrats on a successful pillow palooza!
Marilyn, you have done a double feature. This Post will be featured along with 6 Dishes for Passover on the Blogger’s Pit Stop. Congratulations.
Thnk you Kathleen for letting me know. I am off to buy a lottery ticket. I will split with you if I win!
I don’t have much experience with onions because neither my husband nor I eat them on a regular basis so I am ashamed to say I have never bought any! Thanks for linking up with Friday Funday and please come back again!
A lot of people can’t handle onions Carrie. I will be at your party this week.
This is interesting! I heard that an old remedy for earache and headache involved wrapping a halved onion in a cloth and putting it on your ear! (I have no idea whether that is true :p) I usually store all of my vegetables in the fridge because things tend to go off really quickly in my house! Thanks for sharing on #YumTum this week 🙂
The fridge is good Charlotte. It slows bacteria but doesn’t stop it. Ne er heard the earavhe thing but there is probably something there that makes it work!
Veggies are stored in the fridge. I tend to wash them when I use them. Tomatoes I keep out because the cold ruins them. I only buy what I’ll use for the week too since they don’t stay a long time. That way there is no waste.
All great habits Michelle! I need to learn to cut them up as I need them and watch how long Zi keep them. Thanks for your thoughts!
You have brought our readers at the Blogger’s Pit Stop a real gem that can be vital information for the health of the whole family. Recently I have seen a lot of recalls at the supermarkets for precut salad packs, with people getting sick. We have decided not to buy precut anymore even though it is convenient. I had never thought about cut onions, so I will keep that one in mind too.
Thank you Kathleen. With over 800 recipes I am trying to take my focus to a new direction. Have a great day.
Wow, what great info – thank you for sharing with us at the #HomeMattersParty
Thank you for coming over Jamie. I m glad to help!
My brother is a chef and would throw a fit if he saw my bad cross contamination practices. Thanks for the reminders. Thanks for sharing on Creative K Kids Tasty Tuesdays.
You are welcome Audrey! I am learning so much from researching for my tips series. It is a miracle more people aren’t severely sick. Makes me wonder how many times I say, “must be a bug going around” that it is really contamination!
Great tips Marilyn! I store my onions in the pantry until I cut them. Once they are cut they get stored in zippered bags and placed in the crisper drawer in the fridge along with whole peppers. Cut peppers are stored in the fridge in zippered bags also. You always have a wealth of information and we appreciate you sharing it at Celebrate Your Story link party.
I love zippered bags but I often forget to burp them! You have good habits Sandra.
We keep our leftover onions way to long. From now on after two days they are going in the trash. I never realized cloudy onions meant bacteria – gross.
I know! I feel like doing a documentary on food expiration. It is a miracle I am not sick more often! Thanks for sharing.
I like to use the whole piece so I try not to leave leftovers. Even I don’t like to prepare food in advance of more than one day because I always heard my mom telling me they loose all their nutrients.
Thank you so much for sharing this information with us at Sweet Inspiration party!! Have a wonderful week, Marilyn!
I don’t prepare more than a day in advance either. I wash fruits and veggies thouroghly now and try toavoid bagged and precut items. Even celery and carrots. I have been checking dates now and they are always at least a few days old where I shop even though they say expiration is still good for a week good to see you Pili!
Good point, Marilyn, and why I don’t buy cut lettuce at the grocery store any longer. I haven’t bought cut veggies in awhile (trinity when I’m being lazy), but I won’t do it anymore at all. I should have thought of this before. Thank you for sharing!
I never would wash bagged lettuce ready to eat, or cut veggies in a container. Whole fruits nd veggies I do. With so many recalls and my husband having cancer affecting his immune system I learned. He is always sick. No more salad bars or even restaraunt food that doesn’t get thoroughly cooked!
I had no idea! Thanks for sharing at the “What’s for Dinner” link up!
Onions were the last thingI would have thought I needed to worry about. To ad we had to go to the Dr. To find out!
I always learn something new about cooking with you, Marilyn.
I’m pinning it for later.
Thanks for sharing it.
You are welcome Debbie. I learn a lot researching these tips too! Have a great week. Glad to hear about your clean bill of health!
Uh oh, I’ve been guilty of using cut onions older than 2 days. Maybe I should start freezing them instead. Thanks for the info.
Freezing is good but I read only up to 7 days fom cutting.! It soows down bacteria but doesn’t stop it.
These are great tips! I always use leftover onions, but it’s good to know they should be tossed after 2 days. Thanks for stopping by the Family Joy link party.
I am glad you like them Samantha. This has really got me wondering what other expired it,s are lurking in my kitchen.
I’d never even thought about it but it does make sense – thanks for sharing 🙂
I never would have thought about onions going bad. It is like relish and ketchup, always there when you need it!
Great Tips on the Onions! I had not thought too much about this before, so I appreciate you sharing this very useful information at the Sunday Fitness & Food Link-Up! Pinned 🙂
Thanks Angla. This was definitely an eyeopener for me! I worry about meat and mayo, not precut veggies.
Thank your sharing! Useful post! I really like your articles! I am waiting your next post! 🙂
Welcome to my blog Janet. Thank you for sharing your thoughts. I am glad you liked the post. Have a great week.
I’ve been hearing a lot about onions and storage once cut lately too. I try to use it up as soon as it is cut but sometimes that isn’t possible so I do store it. Good tips!
I don’t don’t think older onions will kill you. Depending on the onion, and how your system is that day though it is like spitting in the wind. I however do freeze them!
Thanks for the updates regarding the cut onions Marilyn. I will be more aware going forward! Have a wonderful weekend and may God bless you and yours!
You are welcome Horace. The old saying “What you don’t know can still hurt you” is so true!
Thanks Marilyn- this information is very helpful . Good post!
Thank you Judee. I never thought about onions or fruits and veggies until it was obvious they were no good until we got really sick.