Food Decay Experiment

Problem Scenario

Broad Question

Which food will last longer without decaying?

Specific Question

Does the source of the food make a difference on the rate of the mold population?


The food containing the most preservatives with last longer without decaying.

Graph of Hypothesis


Independent Variable:

Glass Jars

Dependent Variable:

food items

Variables That Need To Be Controlled:

Vocabulary List That Needs Explanation

General Plan

1: Purchase items needed
2: Take apart foods and place each item in separate jars.
3: take picture of each jar every three days and write down observations.
4: look at mold spores under microscope, and record observations.
5: Do all four steps shown above until finished

Potential Problems And Solutions

Air might seep through jar caps; place plastic wrap around caps.
Mold may have a foul oder.

Safety Or Environmental Concerns

Mold may be poisonous-- wear gloves while handling items.
Toxic fumes may come from mold.

Experimental Design

(add the correct headings from the experimental design page before beginning)

Resources and Budget Table

Jars ($5 each)--Wal-Mart
Burger ($2)--McDonald's
Burger ($7)--Restaurant
french fries ($1)--McDonald's
french fries ($3)--Restaurant
Plastic wrap ($3)--Wal-Mart

Data Table

Time Line

Background Research

  • Molds grow on the inside of the food item; not just on the surface.
  • Mold growth is encouraged by warm/humid weather conditions.
  • There are over 300,000 types of mold.
  • Penicillium is the type of mold that grows on bread.
  • mold needs water, air, food and temperature in order to grow properly.


Detailed Procedure

  • Purchase items needed (processed burger, organic burger).
  • take items apart and put separated items in separate jars.
  • write labels on each jar according to items inside of jar.
  • place cap on jar lid tightly.
  • place plastic wrap over each jar lid to keep air from entering and exiting.
  • take pictures of each item in jars every three days and count mold spores every three days.
  • Keep jars in lighted area (example: next to a window or light bulb).


Photo List


All Raw Data

0 0
0 0
0 0
0 13
0 20
0 32
14 47
19 53
25 62
37 69
41 84
50 96
57 116
64 130




Data Analysis


The food source does make a difference on how fast the food decays


There didn't seem to be any specific trend in the data, except the fact that the mold population continued to increase over the course of two weeks.
Different types of mold grew on different food items. This is so, because different types of mold feed on different types of food, depending on the weather conditions. After the food decomposes, the mold dies off, and cannot survive because it does not have any food to live off of.

Benefit to Community and/or Science

This experiment had a benefit to the community because it warns people about the danger of preservatives. This experiment was to prove that some foods have more preservatives than others do. If people see that a food item comes from McDonald's lasts a lot longer than a food item from Hannaford, they might think twice about which one they choose to purchase and consume. This helps the community, because there is plenty of obesity the United States of America. Preservatives are mainly made out of sugar, which as you probably know, causes many people to gain weight. This is why preservatives may cause people to gain weight. Avoiding these foods from fast food restaurants may help the obesity problem in America. This experiment is beneficial to science, because this experiment is a demonstration as to how food breaks down in your stomach after you consume the food.


My question was: Does the source of the food make a difference on the rate of mold growth?
I have performed this experiment by placing two different foods from different sources in two different jars. The jars were big enough for each item to fit in. Then, I have tracked my progress by simply taking pictures of the items in jars every three days. I have also counted the mold spores that have grown on the items. The jars have been capped tightly, secured with plastic wrap (to make sure that air doesn’t escape or enter) and kept in a lighted area (such as next to a window or light bulb). The purpose of this experiment was to find out if preservatives really have an impact on whether food decays slower or the same. The results revealed that: yes, preservatives do have an impact on how fast the food decays. The contents of food that contain preservatives decayed much slower than the organic food which decayed completely almost within a week. My final conclusion was that the source of the food does make a difference on how fast the content decays.