Sunday, November 07, 2010

Of Mushrooms, Mold and McDonald's

By Monica

The Unhappy Happy Meal

No doubt you’ve heard of that unhappy Happy Meal by now. Photographer places Happy Meal out on the shelf, and it just won’t decompose ...for months... or over a decade! And perhaps you've seen Morgan Spurlock’s McDonald’s burgers that decompose, but the McDonald’s fries that appear to be immortal even after weeks! Morgan Spurlock’s french fry experiment concludes by stating, “How long would they have lasted? Try this experiment for yourself.”

Spurlock, you’re on!

The Need for a Good Mold Study

I decided to set up my own little experiment to test a few simple hypotheses about this supposed lack of decomposition. More details for motivation and rationale are given here.

Over time and in moist enough conditions, many species of fungi can degrade rocket fuel and polycarbonate on CDs. So, given what I'd learned about decomposition over the past 10 years in graduate school (I have both a master's and PhD in mycology), I was pretty confident that fungi and other microbes really shouldn’t have much of a problem with a Happy Meal. But an experiment needed to be done to find out!

The Experimental Design

I hypothesized that the lack of moisture, presence of salt, or presence of certain types of fats might be responsible for the lack of decay that various bloggers and food activists like Spurlock were seeing. That led me to the following experimental design:

McD’s burger (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water
Homemade burger fried in beef tallow (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water
McD’s french fries with salt (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water
McD’s french fries without salt (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water
homemade french fries with salt (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water
homemade french fries without salt (3): glass jar without lid, glass jar with lid, glass jar with lid and 1/3 c water

Because I suspected that the vegetable (seed) oils that McDonald’s uses might have something to do with their lack of decomposition, I decided to do a butter, margarine and “healthy spread” experiment as well.

Butter (3): glass jar without lid, glass jar with lid, glass jar with 1/6 c. water and lid.
Margarine (3): glass jar without lid, glass jar with lid, glass jar with 1/6 c. water and lid. (Highly hydrogenated seed oils)
Smart Balance (3): glass jar without lid, glass jar with lid, glass jar with 1/6 c. water and lid. (Lightly hydrogenated seed oils)
Here We Go!

I wanted to make sure that I didn’t create unintentional bias by pulling out a bunch of old glass jars that have sat in my kitchen for a few years and thus, have varying levels of inoculum. So, I ran all my glassware in the dishwasher before beginning the experiment:


Here are the ingredients from the store. I meant to test two different types of Smart Balance but ended up not having enough jars, so I only tested the normal one, not the lowfat version:


McD's burgers and fries, with storebought (Target) buns and Costco hamburger. The McD's employees were helpful in providing unsalted fries so that I could isolate the salt variable:

The McD's fries (3 salted, 3 unsalted) and salt for the homemade fries (450 mg. per 6.5 oz fries):

Here’s the beef tallow (US Wellness Meats) and potatoes from Target. Getting ready to make the homemade french fries!

Scale and french fry cutter. I wanted to make sure that I placed equal weights of french fries in all the jars (6.5 oz split in three portions, for McD's and homemade fries). A little wine in the background for entertainment as I was waiting for the deep fryer to heat up!

Here are the potatoes I peeled and cut:

Here are the homemade fries:

I placed all foods at the very bottom of the glass jar, and added water to the requisite jars. I noticed that the homemade burger took up the water readily, while it took the McD’s burger several minutes to absorb the same amount. That was interesting.

Homemade hamburgers: happy or not? We’ll see...


And here’s the entire experimental design, set up in my sunroom. You can see that curiosity is killing these cats. "Where's the mold?" They want to know.



Will the McDonald’s fries decompose? Will my homemade fries decompose? Is it the type of fats, the lack of water, or the salt that hinders decomposition of fries? Or none of these? And what about the burgers, the butter, and the “not butter”?


Finally, here are close ups for the start of the experiment, so that we can track the amount of decomposition on each food.

In each case, the jars are in order, from left to right: dry (left), lidded (middle), lidded with water (right). Dry jars are covered with cheesecloth secured by a rubber band. Lidded jars are covered with Kirkland (Costco) brand plastic wrap secured by a rubber band.

Jars 1-3: Salted McD's french fries


Jars 4-6: Unsalted McD's french fries


Jars 7-9: McD's burgers


Jars 10-12: Margarine, Market Pantry brand (Target)


Jars 13-15: Salted butter, Market Pantry brand (Target)


Jars 16-18: Salted homemade fries


Jars 19-21: Unsalted homemade fries


Jars 22-24: Smart Balance "healthy spread" (There are labels still on the outside of these jars, so I wanted to photograph from above so as not to obscure the food.)


Jars 25-27: Homemade burger fried in beef tallow from US Wellness Meats, with Market Pantry brand (Target) white buns, topped with Heinz ketchup (cane sugar, not HFCS). No pickles or onions on the burger.


Thursday Oct. 21, was Day 1 of the experiment. Last week on Day 9, there were small amounts of mold in various jars, but this week we've hit the mother lode!

Stay tuned for this week's McMold results! Meanwhile, I'd love to hear comments about how you think the experiment will turn out, particularly the butter and the "not butter"s!

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