The Tainted Doughnut

After a very successful morning at mass with 2 preschoolers, my husband and I treated the girls to some doughnuts on the way home. You have to reward that good behavior, right? My 4-year-old of course chose the vanilla frosted doughnut with sprinkles. She licked off all the frosting and sprinkles then declared, “I’m done.” She does this with cakes and cupcakes, too. All frosting. So, I picked up the doughnut and took a bite. My husband nearly gagged and turned away in absolute disgust.

“What?”, I said. “This is a perfectly delicious Dunkin’ Doughnut. I’m not going to throw it away.” He replied, “But it’s saliva.”

Saliva? Please. When you are a mom, a little saliva is nothing compared to the other exciting things that come our way. We have been pooped on, thrown up on, and our precious toddlers come to us and say, “Here Mommy!” and hand us their boogers. I figure that since my daughters and I once shared the same blood, a little saliva on a doughnut is nothing to worry about.

So I decided to find out what exactly is saliva, and, as long as my children are not sick, whether I can indulge in that delicious doughnut after the frosting has been licked off.

What is Saliva?

Saliva is a liquid excreted from 3 different pairs of salivary glands in our mouths. These glands are called the parotid, the submandibular and the sublingual glands. Here is a diagram:

Over the course of one day, the salivary glands excrete between 1 and 2 liters of saliva each day. About 98% of saliva is water, but the remaining 2% contains critical components that help us taste, digest, and protect us from bacteria.

How does saliva help me to taste, for example, a fresh doughnut?  In order for our taste buds to detect flavor, the chemicals in foods must first be dissolved by saliva. You will not be able to taste much with a dry mouth (try the experiment below).

Saliva contains several enzymes, such as amylase, which start the digestive process by breaking down the foods we eat. Other enzymes are antibacterial, such as lysozyme. They help to prevent infection and keep our mouths clean.

If you are one of those mothers who endured morning sickness (or 24-7 sickness in my case), there is a reason our mouths salivate right before that dreaded moment. The saliva helps to protect our mouth from the acids coming up from our stomach.

So, after doing some research, I could not find one good reason to throw out the doughnut my daughter had licked. Again, if my daughter had been sick, I would have tossed it. Plenty of illnesses are transferred through saliva. But now I know that saliva is mostly water, and the other components speed up digestion. As far as I’m concerned, my daughter helped me eat the doughnut.

In the future I may pass on other foods that have been licked. But doughnuts? Those are mighty tasty.

Click here for an experiment on saliva and taste.

Sources:

http://digestivesystem.suite101.com/article.cfm/the_many_purposes_of_saliva

http://www.wisegeek.com/what-is-the-purpose-of-saliva.htm

http://kidshealth.org/kid/closet/experiments/experiment_saliva.html

Bleach And “Washable” Paint

As you all know by now motherhood comes with a lot of laundry. Who knew such small people could create massive piles of dirty clothes? My least favorite is what I call The Stain Wash: clothes that had extraordinary encounters with ink, blood, and who knows what else.

This week I found myself battling the stain of all stains, washable brown paint. Yes, I said washable. My daughter came home from preschool with it on her dress. I thought “it will come right out, it’s washable!” Wrong.

The paint held on through the first wash, and resisted Oxiclean’s oxygen action. I then tried my grandmother’s old stand-by, Fels Naptha bar soap. This gets out just about everything. No luck. Then I tried Clorox Bleach Pen (it is a white dress with black dots). The stain was still there. 

Eliminating this stain had become my new mission. I decided to put full-strength straight bleach on the stain, applying it with a small paintbrush hoping to avoid discoloring the black dots. The results are in the photo below.

Even bleach failed to conquer the washable brown paint stain. I had always believed bleach to be the be-all-and-end-all of stain removal. This got me thinking...what exactly is bleach, how does it work, and why didn’t it work this time? I found the following explanation helpful:

Ordinary table salt (sodium chloride, NaCl) is half chlorine, and a simple electrochemical reaction with salt water produces chlorine gas easily. That same reaction produces sodium hydroxide (NaOH), and by mixing chlorine gas with sodium hydroxide you create sodium hypochlorite (NaOCl). When you buy a gallon of bleach at the grocery store, what you are buying is the chemical sodium hypochlorite mixed with water in a 5.25-percent solution. You're buying salt water that has been changed slightly by electricity.

Chlorine also makes a great stain remover, but not because of the chlorine itself. Natural stains (as well as dyes) produced by everything from mildew to grass come from chemical compounds called chromophores. Chromophores can absorb light at specific wavelengths and therefore cause colors. When chlorine reacts with water, it produces hydrochloric acid and atomic oxygen. The oxygen reacts easily with the chromophores to eliminate the portion of its structure that causes the color. (howstuffworks.com)

Aha! So a chemical reaction changes the molecular structure of the chromophores, inhibiting their ability to produce color. Now I understand how bleach works. But why didn’t it work on the dress? Dr. Laundry does not recommend using bleach on spandex, and my daughter’s dress was a cotton-spandex blend. Maybe that small percentage of spandex was enough to keep the bleach from being 100% effective.

So, the next time you turn to bleach to salvage that outfit you just bought, you will have a little more insight into how it is working...or isn’t.

As for the fate of the dress? I decided to live with the light stain that is left on the back, and I filled in the discolored black circles with a Sharpie. 

If you would like to share some science with your kids, click here for an experiment about separating colors.