Running Head: GROWING BREAD MOULD
Growing Bread Mould-A Lab Report
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Introduction
In the Western countries, bread is the most essential staple food. According to Cauvain,
and Young (2007), bread is acknowledged as one of perishable foods, which is only consumed in
its fresh state. However, bread does not stay for long; it stays fresh for a short period of timeimmediately after leaving the oven. In the course of storage, bread is subjected to a series of
changes which results to a loss of its taste and freshness. The circumstances that manipulate the
rate of freshness loss in bread in the course of storage are chiefly separated into two clusters. The
first cluster encompasses those accredited to microbial attack while the second cluster involve
those that are as an outcome of a sequence of sluggish physical or chemical alterations which
result to the advanced fastening of the crumb, generally known as staling( Sivasankar, 2004).
Mould growth is the main cause of microbial spoilage of bread. The least frequent of all kind of
microbial of deterioration in bread is that caused by specific category of yeast. Although warm
weather is equally the least frequent cause of microbial spoilage of bread, it is highly influential
and it causes the bacteria spoilage condition referred to as rope caused by growth of Bacillus
species. Pascoe (2003) contend that mould is a fungus, which depends on other plants for
nourishment. This is because; mould lacks chlorophyll which is extremely critical during the
process of photosynthesis. As a result, moulds are unable to synthesis their own food. Pascoe
indicates that bread mold is not intricate fungus because it obtains its nourishments from flesh,
vegetables or fruits. Mould spores are minute and generally suspended in air. Sivasankar (2004)
observes that after getting conducive environment necessary for its growth, the spore changes
into a living fungus. A mould becomes noticeable immediately after its division and growth and
after a spore has germinated. Eventually, spores form asexually and sexually reproductive
structures at the apex of the hyphae.
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Aim
The aim of this experiment is to determine whether moisture affect the molding rate of
Honey white Bread.
Hypothesis
Moisture affects the molding rate of Honey White Bread.
Materials and Method
The following materials were used in this experiment: Tape, clean container, microscope,
Ziploc bag, Honey White Bread and paper square centimeter. There were two experiments. In
the first experiment, each slice of Honey White Bread was weighed and average weight noted.
Two slices of Honey wheat bread were put into four distinct conditions for a period of four days.
The first two pieces of bread were put close to a window which exhibited intensive sunlight. The
molding process was then measured and recorded after 4 days. Another two slices of bread were
put in a dark room. The molding process was then measured and recorded. Further two slices of
bread were put in a half-lit room and molding process measured and then recorded. The last two
slices of bread were put in a refrigerator and molding process measured and then recorded. The
rate of molding in each four conditions were observed and correlated. The dependent variable in
this experiment was the amount of mould grown on the slices of bread while independent
variable was the atmosphere the two slices of bread were placed in. The control experiment was
the two slices of bread placed in a half-lit room (the condition at which bread is normally kept).
Two critical laboratory precautions were taken in this experiment: both breathing near the bread
and touching the bread with bare hands were carefully avoided.
In the second experiment, two slice of Honey Wheat bread were measured and recorded.
The slices were then placed in two clear containers containing a lid. Tape was wrapped in each
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container. In the first container, the slice of Honey White Bread was placed in a dry jar. In the
second container, the slice was first dipped into water and then placed in a jar. The molding
process was observed and measured with one square centimeter strips. The dependent variable in
this experiment was the length of mould growth while the independent variable was the jar
containing water. The control experiment is the length of mould growth in the jar without water.
Results and Discussion
The original average weight of each slice of Honey White Bread was found to be 22.75
grams. After two slices were exposed in a dark room in the first experiment, the final weight of
each slice of bread was found to be 19.9 grams and 20.2 grams respectively; averaging 20.55
grams. In the refrigerator, the final weight of each slice of bread was found to be 19.5grams and
20.1 grams respectively; averaging 19.8 grams. In the half-lit room, the final weight of each
slice of bread was found to be 19. 5 grams and 20.0 grams; averaging 19. 65grams. After being
placed near the window, the final weight of each slice of bread was found to be 19.7grams and
20.01grams respectively; averaging 19.8 grams. It was discovered that each slice of bread was
hard and considerably shrunken. No mould was found on the slices of Honey White Bread.
However, in the second experiment, mould was observed on the slice of bread that placed in a jar
containing water. It was found out that three centimeter of mould had grown after four days. A
close observation of the slice of bread revealed that the developed mould was pinkish-red in
color. A greenish-blue color normally expected. This indicated that this type of mould was a
unique one. After a careful observation of the slice of bread under a microscope, it was found
out that the mould had not entirely taken over the whole slice of bread. Some parts of the bread
had not been occupied by the mould. It will be accurate to argue that if the slices of bread were
allowed to stay for extra days, the mould could have spread to all part of the bread.
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Table 1: Type of atmosphere and Average Weight of the two slices of bread
Type of Atmosphere
Average Weight (g)
Window
19.8
Half-lit
19.65
Fridge
19.8
Dark Room
20.55
As the above table shows, average weight of the two slices of bread in the dark room is
20.55grams, average weight of two slices of bread in the fridge is 19.8grams, and average weight
of two slices of bread in a half-lit room is 19.65grams while the average weight of bread near the
window is 19.8 grams.
Figure 1: Graph of average weight against type of atmosphere
As the above graph shows, the average weight of two slices of bread in the dark room is
highest followed by fridge, window and lastly in a half-lit room.
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Figure 2: Bread in a Jar after four days
As the above photograph shows, the pinkish -red color indicates the presence of mould.
The white part indicates the absence of mould.
Conclusion
In the first experiment, the hypothesis was not confirmed. The shrinking of the slices of
bread after being placed in the four distinct conditions was a result of the bread losing moisture.
No mould was observed and a result, the experiment was unable to find out which condition was
more conducive for mould’s growth. However, it was established that the shrink of the slices of
bread in the dark room could have been as a result of environmental differences. If the slices of
bread had additional contact with mould spores water or atmospheric air, there could have been
high chance of mould formation. This experiment was deemed to have failed. Nevertheless,
some lessons were learnt from this experiment. Bread requires close contact with mould spores
in order to facilitate mould growth in bread. The second experiment was successful since the
hypothesis was confirmed. After the slice of bread was placed in jar containing water, it made
contact with mould spores and hence the mould started growing on the bread. However, no
mould grew on the dry jar due to absence of moisture.
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References
Cauvain, S.P., & Young, L.S. (2007). Technology of Bread making. New York: Springer
Publishers
Pascoe, L. (2003). Fungi. New York: The Rosen Publishing Group
Sivasankar, B. (2004). Food Processing and Preservation. New Delhi: PHI Learning Pvt. Ltd