Ami

Ami Nakamura Links : Other new experiments:
 * **
 * The progress report of this experiment
 * The 2nd (same) experiment of kimchi
 * The chopped kimchi experiment
 * Kimchi in refridgerator experiment

__Introduction__ Kimchi is eaten by many of people in the world everyday. It is a traditional Korean food. Then how is the Kimchi made? Kimchi goes through fermentation. Our goal is to see how does the fermentation affect the pH of the kimchi, in other words, to see how kimchi will be acidic or alkalinic. Our independant valuable is the time, in days, and our dependent valuable is the pH of kimchi. My expectation is that the kimchi would be more acidic over time. First of all, the fermentation involved in this experiment is the lactic acid fermentaion. The lactic acid fermentation converts glucose into the pyruvic acid, then to lactic acid. So the pH of kimchi should be going down as the glucose in the cabbage gets converted into acids. I am expecting the pH would go down gradually, so i think the pH would be about 1 in the end of this month (May).

__Expectation__ My expectations are:
 * The pH would not change greatly at first, maybe the first week, because the glucose has to be converted into the substances that help produce ATP. I don't think it would be converted so fast because I thought the glycolysis would take a while, it sounds like it is a lot of work to make ATP!
 * After the glycolysis is completed, I thought the pH would go down constantly. Because nothing so complicated is going on agter the glycolysis. (It is just the NADH changes to NAD again.)
 * I think the pH would be close to 1 or 1 in the end of this month.
 * I did not realize this expectation until I saw the results of this experiment, but I was expecting the apparence of the kimchi not so different from the beginning, such as color, and how it looks.

__Materials__:
 * 2 resealable plastic sandwich bags
 * chopped Chinese cabbage
 * Noniodized salt
 * 2.5-mL (1/2 teaspoon) measuring spoon
 * pH-indicator paper
 * thermometer

My experiment models:

__Procedure__: 1) (Bases have pH levels between 7 and 14, and acids have pH levels between 0 and 7. Formulate a hypothesis that explains how fermentation leads to changes in pH. Record your hypothesis and your prediction of how the pH of the kimchi will change over time as it ferments.

2) Put one resealable plastic bag inside the other. Half-fill the inner bag with chopped cabbage. Add 2.5mL of salt. Seal both bags and turn them up-side-down several times to mix the ingredients.

3) Unseal the bags and press down on them to expel any air. Then, reseal the bags. Label the plastic bags containing the kimchi with your name and place them in a cool area where they will remain undisturbed.

4) Each day, observe the kimchi in the bags. Record your observations of any changes in the appearance of the kimchi or the bags in the data table. When a small amount of liquid appears in the bottom of the inner bag, open the bags.

5) Use pH-indicator to measure the pH of the liquid. Record.

6) Press out any gas in the bags and reseal them. Return the bags to the cool area and leave them undisturbed for a week.

7) One week after you first measured the pH, continue to measure the pH. Then, move the bags containing the kimchi to a refrigerator. Record the temperature of the refrigerator in your data table. Continue to observe the kimchi and record its pH every week for 4 weeks.

Cautions: Do not eat the kimchi!**
 * [[file:kimchi pic cover.bmp]]

Results
Data Table
 * Kimchi1 (One week later- in refridgerator)**
 * Day || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 19 ||
 * pH of kimchi || 6 || 4 || 4 || 4 || 5 || X || 4 || 4 || 6 ||
 * Kimchi2 (In the room temperature for the whole time)**
 * Day || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 17 ||
 * pH of kimchi || 5 || 4 || 4 || X || 4 || 4 || 4 || 7 || 8 ||


 * Chopped kimchi (One week later- in refridgerator)**


 * Day || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 17 ||
 * pH of kimchi || 5 || 4 || 4 || X || 4 || 7 || 8 || 8 || 8 ||

(The room temperature was about 23 degrees, in the drawers) This experiments were full of surprise for me. First of all, the kimchi was already not neutral on the first day after mixing with salt, but little acidic. As you can see in the data above, my first experiment with normal cabbage (kimchi1) went down from pH6 to pH4, which surprised me. Then, it was pH4 for a while, then it went up and down. After one week, I moved this kimchi to the refridgerator, which is about 5 degrees. In the end, it was pH 6, to the original pH! Because it showed an unexpected change on 2nd day, I started to think that I might have done something wrong. This Kimchi2, is the experiment under the exactly same condition as the first one for the first week. It was surprising that it was already pH5 from the start. Then, it went down to pH4 also, then stayed there for a while. I remember it smelt like vinegar on the third day, but after it smelt like wines, but later it smelt disgusting. This result was similar to the first one, so I took advantage of this same conditions, and decided to leave this kimchi2 in room temperature for the whole time. However, after one week, it started to be more basic! In the end, it was pH8, and it was so dry that I had to stick the pH indicator paper onto the cabbage. The third experiment was the chopped kimchi. In the biology textbook, it suggested the chopped chinese cabbage, so I tried withthe chopped one. It was also pH5 from the start. It looked like there was less liquid than others...but after putting in refridgerator, there was little more liquid. After one week, in refridgerator, the pH went up and it was now more basic....pH8. On the 17th day, the liquid was really less and yellow. The last one is the kimchi that is in refridgerator the whole time. This one has a really consistant pH. Its apprearance did not change so much, with almost the same color. It always had more liquid than the others. The pH was 5 for a week, then it started to drop to pH4. Different than others, it consistanly went down, but really slowly. It started to have the smell later than others, then it smelt like alcohol on the 5th day finally, but the smell was lost towards the end.
 * Kimchi in refridgerator (In refridgerator for the whole time)**
 * Day || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 17 ||
 * pH of kimchi || 5 || 5 || 5 || 5 || 5 || 5 || 5 || 4 || 4 ||

Discussion
First of all, the result of these experiments were all very different from what I expected. I expected the pH of the kimchi to stay the same for a while, then start dropping down consistantly. However, I can say that the result was nearly opposite of this. It all dropped at least one pH in one day in the beginning. Then, it all stayed there for a while. Very surprisingly, pH of all the kimchi except for the refridgerator one went up after one week! Kimchi2 and the chopped kimchi became even basic in the end, with pH of 8. I found this very strange, because the fermentation is supposed to be creating acids, but the kimchi became basic. The only experiment which make sense was the refridgerator one whose pH slowly, but consistantly went down. Judging by this, I am assuming that the tempreture was the problem in my experiment. The room temprature was about 23degrees, but it would not be consistant. However, the temperature of the refridgerator is consistant. And I am assuming that change was slow in the refridgerator one becasue the cold temperature slowed the process down. I also think it was strange that the cabbage was a little acidic already from the beginning. I could have measure the pH of the original cabbage without salt, so that I might be able to see what caused it to be acidic, other than fermentation. The appearance of the kimchi changed a lot from the beginning, which was different from what I expected. The color turned more like brown as you can see in the results of these experiment. It was much more dry towards the end. Most of the kimchi started smell like alcohol from the second or third day, however soon they smelt something really disgusting, like an used towel that has not been washed for a week. The refridgerator one started to smell like alcohol later than others, but that smell also was gone after, and did not have much smell in the end. To make this experiment better, or when I do this next time, I need to have a better control of the temperature. Also, in my opinion, it is better to have a differnet kind of pH indicator, because i sometimes had to squeeze the cabbage to get the liquid. When I really could not get the liquid, I even stuck the paper onto the cabbage. The textbook said to put the salt of half tea-spoon (2.5ml), but it did not say the amount of cabbage. So I put the random amount of cabbage in the bag, but I still tried to make the amount of the cabbage the same in all the experiments. Next time, I can make the amount of the cabbage more accurate. =**Appendix I**=
 * (Scienctific Terminology)

Is a compound that forms hydrogen ions (H+) in solution. We are making the Chinese cabbage acidic with the salt during fermentation. Is a fermentation that produce ethyl alcohol and carbon dioxide as waste. Equation: pyruvic acid + NADH = alcohol + CO2 + NAD+ Alcoholic fermentation is another kind of fermentation. It does not occur when making kimchi, but it makes bread! Is the process that does not require oxygen. The fermentation in my experiment is anaerobic. This a type of respiration that occurs in an absence of oxygen. Anaerobic respiration is often used interchangeably with fermentation. Is the activated carrier which gives organism energy. I our experiment, only 2 ATP molecules are produced because it is in Lactic Acid Fermentation without any oxygen. Is a domain of unicellular prokaryotes that have cell walls containing peptidoglycan. The fermentation is mostly caused by bacteria. Is any of the unicellular prokaryotic microorganisms of the class Schizomycetes, which vary in terms of morphology, oxygen and nutritional requirements, and motility, and may be free-living, saprophytic, or pathogenic in plants or animals. Is a compound that produces hydroxide ions (OH+) in solution. Base is opposite of acid. One of my kimchi changed to base from acid, suddenly had pH8.
 * Acid**
 * Alcoholic Fermentation**
 * Anaerobic**
 * Anaerobic Respiration**
 * ATP molecules**
 * Bacteria** (http://www.fao.org/docrep/x0560e/x0560e10.htm)
 * Bacterium**?
 * Base**

Is a process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. This is another way for a cell to harvest energy from food, but this one, with a presence of oxygen!
 * Cellular Respiration**

Is a process by which cells release energy in the absence of oxygen. I am making kimchi by fermentation in this experiment. Is the first step in releasing the energy of glucose, and produce NADH. Glycolysis is the first part of the fermentation. A type of sugar that comes from digesting carbohydrates into a chemical that we can easily convert to an energy. The glucose in the Chinese cabbage is needed in glycolysis, which is first part of the fermentation. Salt that had iodine added to help our body stay healthy. In the textbook, it says we need non-iodized salt because iodized salt would already be including salt. So non-iodized won’t work in this experiment. Is the second stage of a cellular respiration that happens in mitochondria. In this process, pyruvic acid is broken down into carbon dioxide in a series of enegy-extracting reactions. Something very similar to this process occurs in the lactic acid fermentation. A group of related bacteria that produce lactic acid. This is the result of lactic acid fermentation with carbohydrates. Is a type of fermentation that produces lactic acid, which generates NAD+ so that glycolysis can continue. It is mainly caused by fungi and bacteria. Is a genus of Gram-positive facultative anaerobic bacteria. This is the common bacteria that cause the lactic acid fermentation. I am assuming that most of the fermentations in my experiment are caused by this anaerobic bacteria.
 * Fermentation**
 * Glycolysis**
 * Glucose**
 * Iodized salt**
 * Krebs Cycle**
 * Lactic Acid Bacteria**
 * Lactic Acid Fermentation**
 * //Lactobacillus//**

Is an organism that is microscopic, or too small for us to see.
 * Microorganism**


 * Mitochondria**


 * Oxidized** (The complete breakdown of [|glucose] to carbon dioxide and water requires two major steps: 1) glycolysis and 2) [|aerobic] respiration. Glycolysis produces two ATP. Thirty-four more ATP are produced by aerobic pathways if oxygen is present. )

Is a measure of the acidity or alkalinity of a solution. I measure the pH of kimchi in order to see if it turned acidic. Is an indicator that measures the pH. I used the pH indicator-papers that changes color according to each pH. Is a process by mostly plants convert light energy and carbon dioxide to a oxygen and energy. This is a way for plants to convert the energy to a useful one, similar to fermentation. Is a colorless liquid formed as an intermediate in fermentation and is an end product in glycolysis.
 * pH**
 * pH indicator**
 * Photosynthesis**
 * Pyruvic acid**

Appendix II
Glycolysis is the first stage of fermentation. The glycolysis takes place in cytoplasm of the cell. This breaks down the glucose in the food, to the substances that helps produce ATP, which is the source of energy needed for fermentation. The Process of Glycolysis (**http://www.bbc.co.uk/scotland/education/bitesize/higher/biology/cell_biology/respiration2_rev.shtml) In the process of Glycolysis, the glucose, which is 6-carbon sugar, turns into 3-carbon Pyruvic acids. The first part is when some carbons in the sugar, usually 2 carbons, seperates and join the NAD, then the NAD becomes NADH2. These is a net gain of 2 ATP. As a result of this process, there are two of 3-carbon pyruvic acids.
 * Glycolysis**
 * [[image:01glycolysis.gif align="left"]]

How are ATP is gained when it is also used in this process?? Two ATPs are used to make this process work, however there are overall two gain of ATPs.

The first ATPs are used, and converted into ADP. Then as the NADH forms, ADP is increased to 4. Then they are converted into 4 ATPs. However there are net gain of two ATPs, because two of the four ATPs are used to continue glycolysis. Picture: (http://www.phschool.com/science/biology_place/biocoach/cellresp/glycolysis.html)

This is a really important process needed to make the fermentation of kimchi succeed. Without stages of Glycolysis, there would be no energy to make the fermentation happen. http://www.esf.edu/efb/course/EFB325/lectures/glycolys.htm

-**Lactobacillus casei ([|bioweb.usu.edu/ microscopy/Research.htm])** Lactobacillus is a major bacteria which causes the fermentation. One of them is called Lactobacillus. I found out that there are more than one tyoe of lactobacillus. They are Lactobacillus casei, Lactobacillus bulgaricus, and Lactobacillus brevis. Bacteria ingest the sugar (from the food), and release an alhocol, acid and carbondioxide. It acts as a mitochondrion in Aerobic Respiration.
 * Bacteria**

Bacteria cause the fermentation. It ingest the sugar (from the food), and release an alcohol, acid, and carbondioxide. Bacteria is know as the thing that changes the glucose in the food to the lactic acid, in most of the fermentation. For example, in yogurt fermentation, the bacteria produce lactic acid, which turns the milk sour, hampers the growth of disease-causing bacteria, and gives a flavor to the yogurt in the end.

(http://sps.k12.ar.us/massengale/images/modlacticacidferm.jpg This is a diagram that shows the process of fermentation. First, the glucose in the food goes into the stage of Glycolysis. As you read in the section of Glycolysis above, the glucose is turned into pyruvid acid in Glycolysis. Those pyruvic acids are used; the cells convert NADH to NAD by passing high energy electrions back to the NAD, which is the electron carrier. This process helps Glycolysis to continue, letting it reuse the NAD. The pyruvic acids are then converted into the lactic acids, producing the net gain of two ATP molecules. This process, after the Glycolysis, is very similar to the Krebs Cycle in the cellular respiration. In the Krebs Cycle, the pyruvic acids are taken, and many of the ATPs are produced by changing NAD to NADH. However, this cannot be part of the lactic acid fermentation because of the absense of oxygen. Oxygen is very important to the Krebs Cycle.
 * Fermentation**

Fermentation is a biggest part of my experiment. It releases energy from food molecules by producing ATP in the absence of oxygen, which is called anaerobic.

In my experiment, I put the chinese cabbage in the Zip-lok and sucked up all the air to make it anaerobic. The process of the fermentation is not only used to make kimchi, but also used to produce wine, vinegar, and yogurt.