I thought that this would help people to find the best place to store the bread so that it would stay fresh and last longer. I also was curious about which factors do most affect the mold’s growth. I learned from my food science subject that mold is a tiny spores in the air that fall into damp food especially bread and grow by producing chemicals that root down the food, which also causes a bad taste for the food. If you look under a high power compound light microscope, you can see these microscopic look like threads that seem to be spread out thickly on the bread.
Bread mold is found in many different types, shapes and colours. The most common bread molds are Penicillium and Aspergillus family. Penicillium and Aspergillus molds usually appear to be similar with spherical shape, also green and grey in colour, but both are different. Aspergillus mold have fine hairs that contain large balloons with spores inside. Some molds cause allergic reactions and respiratory problems. And a few molds such as Aspergillus produce mycotoxins, poisonous substances that can make us sick.
The molds can be controlled by many different factors, such as the temperature, Ph (acidity and bases range), and the moisture. The optimum temperature for molds growth is around 20 – 35 oC and terminated at 100oC. The Ph range for growth is around 2 (acid) to 8. 5 (base), which means that it is extremely hard to control its acidity. They also need moist ground to grow on the surface, but it depends on how much free water particles inside which will changed into solid when the temperature reach 0o C. I have oticed that food left on the counter in the summer molds faster than food left out in the winter, this is the proof that mold likes warm environment. I also found out that the mold grows on the bread even in the dry place, which means that mold just need a very low moisture. My hypothesis is that the bread inside room temperature will grow faster than other samples that inside the refrigerator, because the amount of free water molecules will be decreased or even become solid. III. Materials * 3 slice of Wonder Whole Meal ( White loaf bread ) * 2 Plastic plates 1 Plastic container * 1 Fridge * 1 Freezer * 1 Eye dropper * Water IV. Methods 1. Take out the bread of the package 2. Place one piece on each plastic plates and plastic container 3. Labeled the plastic plates ( B and C ) and the plastic container (A) 4. Take 30 ml amount of water into the eye dropper 5. Drop every 5 drops into each samples, once a day 6. Seal the plastic container 7. Place the plastic container on the counter 8. Put the other plates inside the fridge and freezer 9. Check back every plates every days for a weeks ( around 10. 00 PM ) 10.
Record the data by measure the amount of mold by percentage (%) covered on each pieces of bread. V. Results Over a week and 7 days studies, I saw a slight difference in the amount of mold that grew on every pieces of bread. The bread in the plastic container grew much more than the other samples; even I can barely see the differences between the bread inside the fridge and the freezer. I measured the percent covered by mold on the top side of the bread. Data on % coverage can be seen below. The chart can be seen below in figure 1. Day 1, A=0% B=0% C=0%
In the first day, I prepared all the materials and put them on the counter, fridge and freezer. Day 2, A= 0% B=0% C=0% In the second day, I don’t see any difference on the breads either. In this step I believe that it still need more time before the result comes up. Samples B and C become fragile. Day 3, A=4% B=0% C=0% In the third day, the sample A start to show the mold activities, it covered a small area around the corner of the side and start to shrink a little. But there is no difference on the others samples. The samples B accidently cracked because I put something on it. Day 4, A=11% B=0% C=0%
In the fourth day, the molds on the sample A keep spreading around the surface, its colour is dark green and produce some bad smell, while the other samples still clean. Day 5, A= 15% B=0% C=0% In the fifth day, I saw a little difference in the mold’s area size but the bread really shrinks, the others two stay the same. In this day I try to not put some water into the samples. Day 6, A=15% B=0% C=0% In the sixth day, I can’t see any difference on all the samples which I came up with a conclusion that the mold really needs water to keep grow in the dry situation like Melbourne. Day 7, A=20% B=0% C=0%
In the seventh day, the last day of my study, I found out that the threads of mold keep spreading around the top side o the bread and have a lot more verity of color, such as navy green, dark green and black. In contrast, the other 2 samples showed us that there is no single activity of mold appears but in exchange the bread become so hard and fragile. Figure 1. Percentage of mold coverage on bread VI. Discussion The mold grew a lot more on the bread in the container which stay at the room temperature and there are not even a single mold on the breads that stored inside the fridge and freezer.
I think this is because the free water molecules inside become solid in a day and cause the mold growth to stop. In the seventh day the mold was starting to show a lot of different color. There was pale green, dark green and black color showing up at the end. I think if it kept going, the whole piece would be covered in a month. The bread that stays at room temperature is out of my expectation, because it should be mold faster than this. I believe it was caused by the cold temperature these days, as we entering the winter season. It kept the mold from grows as the free water molecules decreased.
If the bread that you buy is moist and you keep it inside the plastic bags it will mold. So to prevent it from molding you can store it inside the refrigerator, either fridge or freezer is okay. It is still unclear from this experiment about how to slow down the growth of mold other than froze the bread. The frozen bread as the result of stored it inside the fridge will make lose its softness and it was getting as hard as the pores got dry. It can’t return to its original characteristic anymore. The other way is to dry toast it; it won’t mold more than a week since the progress is the same as the refrigerator.
It didn’t look like it could let any more molds to grow. Also, the rate of coverage stopped increasing on the dry bread, so it might be done. VII. Conclusion Mold grows better in a moist environment than it does in a dry environment. The plastic container kept the moisture in and allowed the bread to mold. The temperature is also taking a big part in this experiment which means the lower the temperature, the longer it will stay edible. It seems to be sure that fridge and freezer is one of the best solution to kept the bread stay last longer. VIII. References In a major study of Food Industry (Bee May, 2012), it was found that the Mould is one of the micro organism that cause food poisoning and spoilage. * * Ezine Article. (2005). Bread Mold. Retrieved from http://ezinearticles. com/? Bread-Mold&id=405845 * Abigail’s Bakery. (No Year). Bread Mold Causes. Retrieved from http://www. abigailsbakery. com/bread-recipes/bread-mold-causes. htm * True Visions Microscopes. (2005). Looking at Bread Mold Under the Microscopes. Retrieved from http://www. truevisionmicroscopes. com/looking-at-bread-mold-under-the-microscope. html