Lactic Acidity of Kimchi KIMCHI

Transcription

1 Lactic Acidity of KIMCHI

2 Chapter 1 Lactic Acidity of Lactic acid is a result of lactic acid fermentation. Bacteria produces certain types of acid as fermentation occurs. What exactly is lactic acid fermentation?

3 Section 1 Purpose/Question Scroll: Lactic Acidity: The lactic acidity changes in various types of over fixed intervals. When would be the most acidic point of the various types of over time? When would be the best time to consume kimchi? 2

4 Section 2 Background Information Lactic Acid and Fermentation: Fermentation is a metabolic process that converts sugar to acids, gases or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation. In the process of fermentation, healthy bacteria like lactobacillus will grow. In the case of kimchi, the kimchi will be covered with healthy lactobacilli and lactobacilli is a major part of the lactic acid bacteria group. Some lactobacillus species are produced when foods like kimchi, cheese, or yogurt goes through fermentation. The word bacteria seems to have a stereotype that they have negative effects towards the human body. However, lactobacilli are friendly towards a human body where they live in human s digestive, urinary, and genital systems without causing diseases. The lactobacilli metabolizes the sugar into lactic acid, which lowers the ph of the environment. As a result of lowering the ph, the food will have a sour taste overall. Lactic acid is a chemical compound that plays a huge role in various biochemical processes and was first discovered in the 1789s by the Swedish chemist Carl Wilhelm Scheele. lactic acid has a chemical composition of C3H6O3. As an example of producing lactic acid, kimchi goes through this process called the lactic acid fermentation. In this process of lactic acid fermentation, glucose, fructose, and sucrose is converted into cellular energy and metabolite lactate which are found in plants that undergo fermentation. Gallery 1.3 How to Make Fermented Food Choose fruits to ferment. 3

5 Lactic Acid Fermentation: Lactic acid fermentation is a biological process that makes use of sugar like glucose or fructose, which is converted it into cellular energy and metabolite lactate. During lactic acid fermentation, a redox reaction occurs where one substance is reduced and another oxidized. There are two different kinds of lactic acid fermentation which are heterolactic fermentation and homolactic fermentation. In heterolactic fermentation, a single molecule of pyruvate is converted into lactate. Another molecule of pyruvate is converted into ethanol and carbon dioxide. In homolactic fermentation, both molecules of pyruvate are converted into lactate. Also, homolactic fermentation is the only respiration process that does not produce gas as a byproduct. Ethanol Fermentation: There are two different types of fermentation and ethanol fermentation is one of them. This is a biological process that makes use of sugars like glucose or fructose to convert them into cellular energy and metabolite lactate. One glucose molecule is converted into two ethanol molecules and two carbon dioxide molecules. It is similar to lactic acid fermentation, but the result is different from heterolactic fermentation or homolactic fermentation. Ethanol fermentation reaction described with glucose: C6H13O6 ---> 2 C2H5OH + 2CO2 The main difference between heterolactic fermentation and homolactic fermentation is shown in a simple equation: Heterolactic fermentation with glucose: *Click on the picture *Click on the picture C6H12O6 ---> CH3CHOHCOOH + C2H5OH + CO2 Homolactic fermentation with glucose: C6H12O6 ---> 2 CH3CHOHCOOH 4

6 Glucose: Glucose is generally known has the grape sugar or dextrose which has a molecular formula of C6H13O6 and is present in starch. Glucose is a monosaccharide which means, they are the primary units of carbohydrates. Glucose is a monosaccharide because it is one of the smallest units which have the chemical properties of this class of carbohydrates. Glucose is generally used as an energy source in most organisms including organisms like bacterium, humans, animals, and plants. In plants, glucose is extremely important to their respiratory system of cells. However, since not all glucose is essential for their respiratory system, the leftover glucose is used to strengthen the cell wall or produce protein such as enzymes or chlorophyll. In the case of fermentation, glucose and fructose are fermented by yeast or bacteria. When fermentation happens, glucose and fructose is converted into alcohol and carbon dioxide which will remain dissolved within the water. Gallery 1.1 Open Chain Form of Glucose This is a 2D molecular structure of fructose. Interactive 1.1 Open Chain Form of Glucose Formula: C6H13O6 Molar Mass: g/mol Density: 1.54 g/cm³ Sources: All major carbohydrates Melting Point: 146 C This is a 3D molecular structure of glucose. 5

7 Fructose: Fructose is often interconnected to glucose, because they bond together to form disaccharides(sucrose). However, similar to glucose, fructose is alone a monosaccharide which means it is an isomer for glucose. Fructose is a type of sugar like glucose and also has a molecular structure of C6H13O6. However, glucose and fructose is a different type of sugar because the structure of fructose is different from glucose. Fructose is extremely similar to glucose, but fructose is present in fruits and vegetables and glucose is present in starches. Also, fructose has a different effect from glucose towards the plant which is a quick energy source and is much sweeter than glucose when it is in a raw state. Gallery 1.2 Open Chain form of Fructose This is a 2D molecular structure of fructose. Interactive 1.2 Open Chain Form of Fructose Formula: C6H13O6 Molar Mass: g/mol Density: 1.69 g/cm³ Melting Point: 103 C Sources: Honey, flowers, berries, most root vegetables. This is a 3D molecular structure of fructose. 6

8 Sucrose: Sucrose is a table sugar, which is a white, odorless, and crystalline powder with a sweet taste. It is the most common form that humans will come in contact to and sucrose has a molecular formula of C12H22O11. Unlike glucose and fructose which is a monosaccharide, sucrose is a disaccharide which means it is a more complex compound. Sucrose is composed of glucose and fructose which means they are combined to make sucrose. Even though glucose and fructose are perfectly fine for providing the necessary energy for plants to survive, there is a specific reason behind why plants produce sucrose. Once sucrose is made within plants, it is a compact form of glucose and fructose. It would be a much more efficient way to store the leftover energy from photosynthesizing. Gallery 1.3 Open Chain Form of Sucrose This is a 2D molecular structure of sucrose. Gallery 1.4 Table Sugar Formula: C12H22O11 Molar Mass: g/mol Density: 1.59 g/cm³ Melting Point: 186 C Source: Sugar beets, sweet peas, most dried fruit and some fresh fruit such as mangoes and peaches This is a picture of sucrose (table sugar). 7

9 How Glucose and Fructose are Made: Glucose and fructose is a result of photosynthesis in plants where plants undergo to make energy for themselves. When plants undergo the process of photosynthesizing, they need three components which are light, water, and carbon dioxide. Light energy is converted into chemical energy and that energy is stored inside a bond of sugar and oxygen is produced as a byproduct. Photosynthesis takes place in the chloroplasts, particularly using chlorophyll, the green pigment that is required in photosynthesis. As a result of photosynthesis the sugars glucose and fructose are produced. Sucrose is also produced, but sucrose has to undergo another step, which is glucose and fructose combining. Sucrose is then stored in the plant, therefore sucrose is the sugar most commonly extracted from plants by humans. Law of definite proportions: Using the law of definite proportions, it is able to be seen that all fructose, sucrose, and glucose use the same elements. However, they all have different ratios of elements needed, but regardless of the amount, a compound is always composed of the same elements in the same proportion by mass. By using the law of definite proportions, scientists were able to determine the three different types of sugar, which are glucose, fructose, and sucrose. Audio 1.1 Photosynthesis The process of photosynthesis described: Carbon Dioxide (CO2) + Water (H2O) (Using light energy and chlorophyll) ---> Carbohydrate (Glucose and Fructose) + Oxygen Listen to this background music when reading this page. (Media) 8

10 : is a traditional fermented Korean side dish that consists of vegetables with a variety of seasonings. is often described as spicy (the spice includes hot pepper) or sour (the process of lactic acid fermentation results the kimchi to get sour) and it is stored underground in jars for over months. However, since refrigerators are usually existent in most homes, people store it in the refrigerator instead of storing underground in jars. The Field Museum has documented 187 historical and current varieties of kimchi. How each kimchi is differentiated by the different types of ingredients or spices added. The ingredients that are added to the are not fixed, but the most common ingredients include: Influence of the : is known to be an extremely healthy food to the many other countries. According to the Taste of Asia, kimchi is one of the top five healthiest foods in the world. has become a controversial issue in the food aspect. Health Magazine named kimchi in its list of top five World s Healthiest Foods for being rich in vitamins, aiding digestion, and even possibly reducing cancer growth. is still being researched and studied by scientists because they are trying to figure out the positive effects of the kimchi.amongst all 187 documented historical and current varieties of kimchi, white radish kimchi, leek kimchi, cabbage kimchi, and cucumber kimchi is the most commonly known kimchis. All four of these have the same spice, but the main ingredient is different. The white radish, leek, cabbage, and cucumber will result the kimchi to have a different amount of water or salt. 1. Brine 2. Scallions Gallery 1.1 Ingredients Necessary for Making 3. Spices 4. Ginger 5. Garlic 6. Shrimp sauce 7. Fish sauce Brine (salt water) 9

11 Movie 1.1 Necessary Ingredients for Making This is the process of how kimchi is made and the necessary ingredients. 10

12 Section 3 Hypothesis and Variables Hypothesis: 1st hypothesis: If the lactic acidity change in several types of over fixed intervals is measured, then the amount of lactic acid will increase the first 3 to 4 days, but will decrease afterward. This is because the bacterium within the will start dying after 3 to 4 days, resulting in the to have less lactic acid. Variables: Controlled variables: Temperature, amount of, types of. Independent variable: Intervals that the observer measured. Dependent variable: Lactic acidity change within a. Gallery 1.5 Lactobacilli Bacterium 2nd hypothesis: If the lactic acidity changes, the greatest time to consume would be on the 3rd or 4th day, because that moment is the time where lactic acid exists the most. If the lactic acidity is high, that means bacterium exist more. The healthy bacteria called lactobacilli found in is healthy for the human body. This is a picture of a lactobacilli bacterium. 11

13 Section 4 Material List and Methods Gallery 1.6 Materials Required for this Experiment Material List: g of Cabbage g of White Radish g of Cucumber g of Leek g of spice for each 6. 4 containers that are made up of plastic that has a lid for each that is made up of rubber. Each container with the lid has a volume of 590mL. 7. ph meter 1. 30g of cabbage kimchi with 200g of spice. The container is made out of plastic and the lid if made out of rubber. 12

14 Method: Interactive 1.3 How the ph Meter Works 1. Measure the temperature of the room with a thermometer. ph Meter: 2. Make sure the temperature of that specific room doesn t change and the temperature should be 25ºC, since the room temperature is 25ºC. Power Button 3. Prepare 800 g (200 g for each ) of spice in order to make. 4. Prepare 30 g of cabbage, 30 g of white radish, 30 g of cucumber, 30 g of leek. Set Hold: Thermometer: 5. Combine 30 g of each vegetable to 200 g of spice to make. 6. Prepare 4 containers that are made up of plastic so it conducts heat slowly from the exterior. 7. Prepare 4 lids that are made out of rubber to fit on each Gallery 1.7 Measuring the ph with the ph meter container, so it prevents air from the exterior. 8. Check the lactic acidity with the ph meter daily for 2 weeks. 9. Record the ph of each daily. 10. Repeat procedure 4 to 6 at fixed intervals. Record the data. These are leek kimchi, cabbage kimchi, white radish kimchi, and cucumber kimchi in order. The experiment is carried out with measuring the ph (lactic acidity) with the ph meter. 13

15 This video shows the lactic acidity being measured with the ph meter. This is just visual presentation to show how the ph meter is used to carry out this experiment. Movie 1.2 How the Experiment is Carried Out This is not the real process of experimenting, since the ph meter needs to be rinsed every time the ph meter enders a substance. Also, the lactic acidity of each kimchi needs to be recorded, However, this video is to show how the experiment will look like if the tester followed the procedures. 14

16 Section 5 Data Analysis ph Data Chart: Day / White Radish Leek Cabbage Cucumber Patterns: The ph of the kimchi started out the same which was 3.6. After the first day, the ph of all 4 kimchi seemed to be rising constantly until the fourth day. This represents that the lactic acid has decreased, but on the fifth day, the ph went down, which means the lactic acid has increased. The solution is more acidic if the ph is lower and the solution is more basic if the ph is higher. Starting from the sixth day, the ph increased constantly until the tenth day. On the eleventh day, the ph has dropped and after the eleventh day, the ph kept increasing until the fourteenth day. Patterns are difficult to find in this ph data chart. However, the most noticeable change in this ph data chart is that the ph of all 4 kimchis dropped drastically on the fifth day. The ph dropped by one which means the amount of lactic acid has increased. 15

17 5 White Radish Leek Cabbage Cucumber ph Change of Several s Over Time ph Day 16

18 Observations before the experiment: When the experiment first started, these were some observations that were first observed: Sight: The vegetables are able to be seen and the color of all 4 kimchi is red. Hearing: N/A Touching: The vegetables are rigid, and the spice mostly consists of water, so it feels like water. Smell: It smells like vegetables and spice Tasting: The taste is spicy Observations after the experiment: These are some observations that changed throughout the whole experiment: Sight: The vegetables are able to be seen and the color of all 4 kimchi is red. Hearing: N/A Touching: The vegetables are rigid, and the spice mostly consists of water, so it feels like water. Smell: It still smells like vegetables and spice, but it smells extremely bad. This is due to lactic acid fermentation. Tasting: The taste is spicy and extremely sour. The sour taste overwhelms the spicy taste. Observations during the experiment: During this experiment, there were some remarkable observations that could be made with the changes. It has been stated in the background information that lactic acid fermentation, biological process that makes use of sugar like glucose or fructose, which is converted it into cellular energy and metabolite lactate. There are two main types of lactic acid fermentation which are heterolactic fermentation and homolactic fermentation. Heterolactic fermentation with glucose: C6H12O6 ---> CH3CHOHCOOH + C2H5OH + CO2 If this equation is correct, a byproduct, carbon dioxide is produced in the process of the experiment. This reaction was noticeable in the experiment because the containers for the kimchi were slightly opened. Once the rubber lid from the container was removed, it sounded like if gas wanted to escape that container. This proves that the heterolactic fermentation happened within the kimchi. Gallery 1.8 Heterolactic Fermentation The container on the right compared to the container on the left has the rubber lid slightly open. This proves that carbon dioxide was produced on the right container. 17

19 Section 6 Conclusion Purpose of this Experiment and Summarization: The purpose/question was The lactic acidity changes in various types of kimchi over fixed intervals. When would be the most acidic point of the various types of over time? The purpose of this lab was to figure out the most acidic point of kimchi over time. gets more acidic if more lactic acid is produced by bacterias called lactobacilli. In this experiment, the tester demonstrated the lab for 2 weeks accordingly to the procedure. The observer had to measure the ph for each kimchi, leek kimchi, cabbage kimchi, white radish kimchi, and cucumber kimchi daily, under the same circumstances. By recording the data and assembling the data to make a graph, the lactic acidity for each kimchi was able to be observed smoothly. As data was collected from the experiment, the main inquiry was solved by figuring out when kimchis had the highest lactic acidy. Another purpose of this experiment was to figure out When would be best time to consume kimchi? Even though the best time to consume kimchi is completely subjective, the best time to consume kimchi exists. Through figuring out the most acidic point of kimchi, When would be the best time to consume kimchi? would be solved automatically. Gallery 1.9 Acid-Base Indicator Through using the acid base indicator, you can figure out if a substance is acidic or basic. 18

20 Summarization of Results and Relationships: The purpose/question was: The lactic acidity changes in various types of over fixed intervals. When would be the most acidic point of the various types of over time? When would be the best time to consume kimchi? Fermentation is a metabolic process that converts sugar to acids, gases or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation. In the process of fermentation, healthy bacteria like lactobacillus will grow. In the case of kimchi, the kimchi will be covered with healthy lactobacilli and lactobacilli is a major part of the lactic acid bacteria group. Lactobacilli grows in the process of fermentation, and they produce a unique type of acid called the lactic acid. Lactic acid is a chemical compound that is essential in various biochemical processes. Lactic acid has a chemical composition of C3H6O3. As an example of producing lactic acid, kimchi goes through this process called the lactic acid fermentation. In this process of lactic acid fermentation, glucose, fructose, and sucrose are converted into cellular energy and metabolite lactate which are found in plants that undergo fermentation. Fermentation is caused by lactobacilli that produce lactic acid and as a short term, this is called the lactic acid fermentation. Lactic acid fermentation is a biological process that makes use of sugar like glucose or fructose, which is converted it into cellular energy and metabolite lactate. During lactic acid fermentation, a redox reaction occurs where one substance is reduced, and another oxidized. When lactic acid fermentation occurs in kimchi, the lactic acidity of kimchi is diverse dependent on the time. As the data was continuously being recorded daily, the question, When would be the most acidic point of the several types of over time? was able to be solved. According to the table in section 1.5, the fifth day had the highest lactic acidity. From the first day of the experiment to the fourth day, the lactic acidity constantly went down, and the acidity was not changing drastically. However, on the fifth day, the lactic acidity unexpectedly went up from approximately ph 4.2 to ph 3.1. The fifth day had the highest acidity rate. Day / White Radish Leek Cabbage Cucumber

21 However, after the fifth day, the lactic acidity went down and did not have any major transitions until the end of the experiment. Day / White Radish Leek Cabbage Cucumber When lactic acid fermentation occurs in kimchi, lactic acid is being produced by a bacteria called lactobacilli. The word bacteria seems to have a stereotype that they have negative effects towards the human body. However, lactobacilli are friendly towards a human body where they live in human s digestive, urinary, and genital systems without causing diseases. The lactobacilli metabolizes the sugar into lactic acid, which lowers the ph of the environment. As a result of lower the ph, the food will have a sour taste overall. Another question of this experiment was to figure out When would be best time to consume kimchi? Even though the best time to consume kimchi is completely subjective, the best time to consume kimchi exists. Lactobacilli is a type of a bacteria that releases lactic acid in the process of fermentation. Since lactic acid is healthy for the human health, the most acidic point of kimchi would most likely be the best time to consume kimchi. Through figuring out the most acidic point of kimchi, When would be the best time to consume kimchi? was solved automatically. The fifth day had the highest lactic acidity so the fifth day after kimchis are made would be the best to consume kimchi. The ph of white radish kimchi was 3, leek kimchi was 3.2, cabbage kimchi was 3.1, and cucumber kimchi was 3. This was such a short period of time and the short period of time and amount of lactobacilli are correlated. Bacteria in common cannot live long when they are outside without protection. Lactobacilli will reproduce and produce lactic acid during those first four days, and when the lactobacilli reaches its maximum number, they will make lactic acid for that short period of time and die. 20

22 Hypothesis: 1st hypothesis: If the lactic acidity change in several types of over fixed intervals is measured, then the amount of lactic acid will increase the first 3 to 4 days, but will decrease afterward. This is because the bacterium within the will start dying after 3 to 4 days, resulting in the to have less lactic acid. I reject this hypothesis because the amount of lactic acid only drastically increased on the fifth day. The first hypothesis states that the amount of lactic acid will constantly increase until the bacterium dies. However, lactobacilli released a large amount of lactate acid only on the fifth day. Rather than the lactic acid constantly increasing, the amount of lactic acid decreased in a slow rate. Day / White Radish Leek Cabbage Cucumber nd hypothesis: If the lactic acidity changes, the greatest time to consume would be on the 3rd or 4th day because that moment is the time where lactic acid exists the most. If the lactic acidity is high, that means bacterium exists more. The healthy bacteria called lactobacilli found in is healthy for the human body. I reject this hypothesis because the number of lactobacilli only suddenly increased on the fifth day. The second hypothesis states that the greatest time to consume kimchi is on the third or fourth day. Therefore, the fifth day would be the greatest time to consume kimchi since the amount lactic acid has increased the most on the fifth day. Day / White Radish Leek Cabbage Cucumber

23 Data that Could Have Gone Wrong: While demonstrating the lactic acidity in kimchi lab, there were variety of aspects that could have gone wrong. First, the temperature of the room might have changed the data outcome. Since the experiment continued on to 14 days, the temperature was not exactly 25ºC everyday. The goals was to leave the room temperature to be 25ºC, but there were some days colder than others. The reproduction of lactobacilli or the speed of producing lactic acid might be dependent on the room temperature. Two Questions Related to this Topic: 1. If kimchi grew bacterium in the process of fermentation, then when would the bacterium reach its maximum limit? 2. Which fermented food produces lactic acid the most? *Scroll Second, the amount of water within the container might have led to wrong data. The initial amount of water that went inside the container was 200g, but since there is water within the vegetables themselves, it might have changed the amount of water. The amount of water is extremely important because the ratio of amount of lactic acid : water should be reasonable for each experiment. Third, the distribution of spice might have led to wrong data. The spice for all four kimchis was all the same. However, in the process of distributing spice to each vegetable is different. There are certain types of vegetables that absorb more spices than others. 22

24 Section 7 Review Review 1.1 Photosynthesis Review 1.2 Sucrose Review 1.3 Bacteria What kind of sugar is produced right after photosynthesizing? A. Glucose B. Table Sugar C. Sucrose What two types of sugar do plants convert to make sucrose? A. Table sugar and Glucose B. Glucose and Fructose C. Fructose and Table sugar What kind of bacteria produces lactic acid? A. Mitis Group B. Escherichia coliare C. Staphylococcus aureus D. Lactobacillus Check Answer Check Answer Check Answer 23

25 Review 1.5 Types of Review 1.4 ph Meter What do each number represent in this ph meter? Which of these four is leek kimchi? Temperature ph ph Temperature Check Answer Check Answer 24

26 Section 8 Resources "Lactic Acid 3D." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "." Wikipedia. WIkimedia, n.d. Web. 17 Mar < Fresh, Maangchi. Maangchi LLC, n.d. Web. 17 Mar < "How to Ferment Fruit." WikiHow. MediaWiki, n.d. Web. 17 Mar < "Outline." CELLULAR RESPIRATION: HARVESTING CHEMICAL ENERGY., n.d. Web. 17 Mar < mnmelanchapter_9_cellular_respiration.htm> "Glucose." Wikipedia. WIkimedia, n.d. Web. 17 Mar < < "Photosynthesis." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Brine." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Scallions." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Spices." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Ginger." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Garlic." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Fructose" Wikipedia. WIkimedia, n.d. Web. 17 Mar "Shrimp Sauce." Wikimedia. WIkimedia, n.d. Web. 17 Mar < < %BC:Korean.cuisine-Jeotgal-Saewoojeot-02.jpg> "Sucrose" Wikipedia. WIkimedia, n.d. Web. 17 Mar "Fish Sauce." Wikimedia. WIkimedia, n.d. Web. 17 Mar

27 < "Lactobacillus." Wikimedia. WIkimedia, n.d. Web. 17 Mar < "Bacillo Lacto Wikimedia. WIkimedia, n.d. Web. 17 Mar "Science company." ph., n.d. Web. 17 Mar < "SF Gate." ph., n.d. Web. 17 Mar < W162.aspx> "Photosynthesis." Leaf Structure ph., n.d. Web. 17 Mar < "Cheese." Wikipedia. WIkimedia, n.d. Web. 17 Mar < "Wine." Wikipedia. WIkimedia, n.d. Web. 17 Mar < Yogurt Wikipedia. WIkimedia, n.d. Web. 17 Mar < 26