DO DIFFERENT TYPES OF BREAD MOLD AT DIFFERENT

RATES WHEN SATURATED WITH WATER?

By ReNee, Lisa, Meaghan and Elizabeth

QUESTION AND PREDICTION

QUESTION: Do different types of bread mold at different rates when saturated with water?

PREDICTION: We thought that the doughnut would mold the fastest due to the amount of sugar and oil it contains. We thought that the English muffin would mold the slowest because it was had less moisture in it to begin with.

MATERIALS

We used six different types of bread 7 Grain Sourdough Doughnut White Preservative-Free Bread English Muffin Whole-Grain Bagel Cinnamon Crunch Petri Dish Water Notebooks Transparency Graph Adhesive Tape

VARIABLES

Constant Variables Light Air Water Temperature

Independent Variable Different Types of Bread

Dependent Variable Rate of Mold Growth

PROCEDURE Step 1: Gather the six different types of bread (keep

the original white bread from the previous experiment to ensure all conditions are the same)

Step 2: Cut slices to fit the size of each graph which will lay on top of each dish. Then place each slice of bread into a different Petri-dish

Step 3: Dampen each slice of bread with three even sprays from the spray bottle

Step 4: Seal each Petri dish with adhesive tape with transparent graph centered on top of each lid

Step 5: Create chart to record data, see next slide for example

Step 6: For the next three weeks, on Mondays and Wednesdays, record the number of squares on the transparency that the mold covers

EXAMPLE OF DATA CHART FROM SCIENTIFIC NOTEBOOK

Day 7 Grain White Bread

Bagel English muffin

SourDough

Doughnut

MOLD DATA

Day 7 Grain White Bread

Bagel English muffin

SourDough

Doughnut

1 2/15/10

0 0 0 0 0 0

3 2/17/10

0 0 0 0 0 0

8 2/22/10

13 45 0 0 0 1

10 2/24/10

29 91 0 0 0 1

15 3/1/10

61 100 1 0 0 2

17 3/3/10

61 104 1 0 1 2

22 3/8/10

144 144 49 0 1 2

MOLD GROWTH DATA

Mold Pictures

White English Muffin Sourdough

7-Grain Doughnut Bagel

OUR CONCLUSION

We have found that the different types of bread, when saturated with water, do not influence the mold growth, however, the presence of preservatives influences how

quickly the bread molds The 7 Grain and the White Bread were preservative free and they molded quickly

and fiercely The English Muffin, Doughnut, Sourdough,

and Bagel contained preservatives and molded slowly if at all

SUPPORT FOR CONCLUSION

Dr. Fred Stein, consulting educator for greatschools.org states that, “Preservative-free bread is a wonderful medium for producing mold, which grows from spores (the mold equivalent of plant seeds) that are already present on the bread.” http://www.greatschools.org/students/activities/make-a-bread-mold-garden.gs?content=148

Diane Helmuth, Douglas County Extension Specialist for Food and Nutrition states in her article, “Preservative Free Bread Needs Refrigeration” To see her article go to: http://news.google.com/newspapers?nid=2199&dat=19800416&id=LKgyAAAAIBAJ&sjid=R-cFAAAAIBAJ&pg=4399,2899937

SUPPORT FOR CONCLUSIONS CONTINUED

“There are two general approaches that can be taken to reduce mold growth on bread. Reduced water activity and chemical preservatives,” says Ed O’Neil, Microbiologist from the MADSCI Network. www.madsci.org