FuN Experiment 4 : On VitamiN C

Introduction: 

Vitamin C also known as ascorbic acid that is an essential nutrient to humans. The vitamins protect the body from oxidative stress and prevent scurvy. Plants can make it themselves as can some animals, but humans do not have the right enzyme.

One way to determine the concentration of vitamin C in food is titration of ascorbic using iodine. As long as Vitamin C in the solution, the iodine will react. A starch solution is used as an ‘indicator’ because it turns black in the presence of iodine. The black color is the end point of the titration. This titration procedure is appropriate to test the amount of Vitamin C in food and this experiment we are using white cabbage. This experiment will test the effect of boiling and prickles compared to raw cabbage in its Vitamin C concentration. Then, the application of starch oxidizing used to produce a magic ink.

Abstract

Target for this experiment is to measure the presence of vitamin C by using starch –iodine test and its application in daily life. So the food containing Vitamin C such as raw cabbage is used to be tested with starch solution. The cabbage blended with distilled water to produce strain extracts added with HCL, starch solution and then titrated with iodine solution. The addition of iodine to the extract with starch containing to measure the starch concentration is called titration. The addition of iodine is continuous until the extract solution stays in blue- black colour for 15 minute and its reading of iodine amount is recorded. The average is focussed on and the result is presence of 0.36 mg/ml concentration of Vitamin C in white raw cabbage. Raw cabbage is rich in Vitamin C as much as Lemon juice. Other test was held using boiled white cabbage, using the same concept, the iodine used to titrate the starch extract assumed as the concentration of Vitamin C presence in it. Result shows that boiled white cabbage has lower concentration of Vitamin C compared to raw white cabbage with average concentration only 0.10 mg/ml. Conclusion made that boiling technique will reduce the Vitamin C in white cabbage because it will change Vitamin C structure. For another test, pickled white cabbage is used and the results located between these two earlier test with average concentration 0.14 mg/ml of Vitamin C. so prickling also cause moderate loss of Vitamin C due to its water soluble characteristics. For the application of starch iodine test, magic writing experiment is conducted. The lemon juice is used as ink to write in a piece of paper and then submerged it in iodine solution. The results shows that the ink will be reveal after the paper is held near the heat because of oxidation occurs and turn brown when heated. So from this experiment we know that simple test of starch iodine interaction can test presence of Vitamin C concentration and it can be used to create magic ink too!. 

Procedure :

      1)      Preparing vitamin C extracts from raw white cabbage.

 

 

 

 

 2)      Measuring vitamin C in the food sample.

Results :

Volume of iodine use in titration = Volume of vitamin C in the raw white cabbage

a)      Calculation of Vitamin C in ascorbic acid (standard)

1 mg/ml of ascorbic acid = 77.00 ml of iodine solution (during titration)

b)      Calculation of Vitamin C in raw cabbage (Raw 1)

·         Volume of iodine used in titration until raw cabbage 1 turns to blue black in color is 26.10 ml. Compared with standard volume of Vitamin C acid in ascorbic acid.

1 mg/ml of vitamin C = 77.00 ml of iodine solution

X  mg/ml of vitamin C in raw cabbage 1 = 26.20 ml of iodine solution

X mg/ml of Vitamin C = (26.20ml/77.00ml) x 1 mg/ml

                                     = 0.34 mg/ml

·         Therefore, concentration of Vitamin C in raw cabbage 1 is 0.34mg/ml

·         If 0.34 mg/ml of vitamin C in raw cabbage = 30 g of cabbage

         X mg/ml of vitamin C in raw cabbage = 100 g of cabbage

         X mg/ml of vitamin C in raw cabbage   = (100g/30g) x 0.34 mg/ml

                                                                        =  1.13 mg/ml

·         Therefore, 100 g of raw cabbage contain 1.13mg/ml of Vitamin C.

  

c)      Calculation of Vitamin C in raw cabbage (Raw 2)

·         Volume of iodine used in titration until raw cabbage 1 turns to blue black in color is 28.80 ml. Compared with standard volume of Vitamin C acid in ascorbic acid.

1 mg/ml of vitamin C = 77.00 ml of iodine solution

X  mg/ml of vitamin C in raw cabbage 1 = 28.80 ml of iodine solution

X mg/ml of Vitamin C = (28.80ml/77.00ml) x 1 mg/ml

                                     = 0.37 mg/ml

·         Therefore, concentration of Vitamin C in raw cabbage 1 is 0.37mg/ml

·         If 0.37 mg/ml of vitamin C in raw cabbage = 30 g of cabbage

         X mg/ml of vitamin C in raw cabbage = 100 g of cabbage

        X mg/ml of vitamin C in raw cabbage   = (100g/30g) x 0.37 mg/ml

                                                                        =  1.23 mg/ml

·         Therefore, 100 g of raw cabbage contain 1.23mg/ml of Vitamin C.

d)     Average concentration of Vitamin C in 30g of raw cabbage

·         (0.34 + 0.37mg/ml)/ 2 = 0.36 mg/ml

  

Discussions :

            From this experiment, concentration of vitamin C from raw white cabbage has been determined by using titration method. Iodine was used in this titration process because it can react with vitamin C after it reacts with starch in the raw cabbage. In this experiment, we had determine that the concentration of Vitamin C  in average 0.36mg/ml per 30 g of raw white cabbage.

            White cabbage rich in Vitamin C as much as Vitamin C in lemon juice. Vitamin C helps heal cuts and wounds, maintain collagen and keeps gum healthy. Besides Vitamin C, cabbage also contains a lot of nutritional values that needed by the body such as high in bioflavanoids, good sources of manganese, folate, Vitamin B6, potassium and omega  3 fatty acids. Moreover, raw cabbage also rich in vitamin B1, vitamin B2, calcium, potassium, magnesium, Vitamin A and some protein.

Cabbage also rich in antioxidant nutrients which important in health maintenance and neutralize harmful chemicals that called “free-radicals” that cause cell damage in the body. Heat will give slightly effect to reduce vitamin C if the cabbage was overcooked. The best way to cooked raw cabbage is steaming rather than boiling because it minimize the loss of water-soluble nutrients like vitamin C. How long cooking time for the cabbage is actually depends on the surface area of the cabbage.

Conclusions :

In a conclusion, to keep vitamin C in its original form and value, we need to minimize its contact with water and cooked in short period of time.

 B) Boiled White Cabbage

      Volume of iodine use in titration = Volume of vitamin C in the boiled white cabbage

a)      Calculation of Vitamin C in ascorbic acid (standard)

1 mg/ml of ascorbic acid = 77.00 ml of iodine solution (during titration)

b)      Calculation of Vitamin C in boiled cabbage (Boiled 1)

·         Volume of iodine used in titration until boiled cabbage 1 turns to blue black in color is 7.50 ml. Compared with standard volume of Vitamin C acid in ascorbic acid.

1 mg/ml of vitamin C = 77.00 ml of iodine solution

X  mg/ml of vitamin C in boiled cabbage 1 = 7.50 ml of iodine solution

X mg/ml of Vitamin C = (7.50 ml/77.00ml) x 1 mg/ml

                                     = 0.10 mg/ml

·         Therefore, concentration of Vitamin C in boiled cabbage 1 is 0.10mg/ml

·         If 0.10 mg/ml of vitamin C in boiled cabbage = 30 g of cabbage

         X mg/ml of vitamin C in boiled cabbage = 100 g of cabbage

        X mg/ml of vitamin C in boiled cabbage   = (100g/30g) x 0.10 mg/ml

                                                                        =  0.33 mg/ml

·         Therefore, 100 g of boiled cabbage contain 0.33mg/ml of Vitamin C.

c)      Calculation of Vitamin C in boiled cabbage (Boiled 2)

·         Volume of iodine used in titration until boiled white cabbage 1 turns to blue black in color is 7.80 ml. Compared with standard volume of Vitamin C acid in ascorbic acid.

1 mg/ml of vitamin C = 77.00 ml of iodine solution

X  mg/ml of vitamin C in boiled cabbage 1 = 7.80 ml of iodine solution

X mg/ml of Vitamin C = (7. 80ml/77.00ml) x 1 mg/ml

                                     = 0.10 mg/ml

·         Therefore, concentration of Vitamin C in boiled cabbage 1 is 0.10mg/ml

·         If 0.10 mg/ml of vitamin C in boiled cabbage = 30 g of cabbage

         X mg/ml of vitamin C in boiled cabbage = 100 g of cabbage

         X mg/ml of vitamin C in boiled cabbage   = (100g/30g) x 0.10 mg/ml

                                                                        = 0.33 mg/ml

·         Therefore, 100 g of raw cabbage contain 0.33mg/ml of Vitamin C.

d)     Average concentration of Vitamin C in 30g of boiled cabbage

·         (0.10 + 0.10 mg/ml)/ 2 = 0.10 mg/ml

Discussion:

-           The concentration of Vitamin C in boiled white cabbage is lower than raw white cabbage. The average concentration of Vitamin C in 30g of boiled cabbage is 0.10 mg/ml rather than in raw cabbage 0.37 mg/ml. When we boiled white cabbage with water, Vitamin C inside it actually will degrade with heat.Vitamin C is one of the least stable of all vitamins in solution and is oxidized readily in light, air and when heated.

-          Besides that, Vitamin C is also water soluble. This means that heating in water (like white cabbage in boiling water) causes the vitamin to leach out of the food into the water and also oxidized. First oxidized to dehyroascorbic acid and then to diketogulonic acid.The spontaneous oxidation of Vitamin C occurs upon contact with air and is triggered by the presence of heat that speed up this reaction, so that the structure of Vitamin C is changed more quickly.

-          Therefore, when we used a method of boiling in cabbage we actually creating a heat-oxygen-water combination that acts in concert to change the structure of vitamin C.To make sure the Vitamin C is retain in greater percentage when we use a boiling method, make sure we take this prevention:

a)      Don’t soak vegetables in water prior to cooking them.

b)      Refrigerate the vegetable in a covered container until we already to boil the.

c)      Boil the vegetables whole if possible

d)     Use the smallest amount of water possible to boil the vegetables and don’t boil them any longer than is necessary.

e)      Serve the food immediately after remove them from water.

f)       Some vitamins are present in the water that used for boiling, so use the water in gravies or soups.

Conclusion:

-          In a conclusion, using boil technique in white cabbage will reduce the Vitamin C contain inside it. This is because Vitamin C is unstable water soluble and when it loss in water heat will change the structure of Vitamin C .

C) Pickled white cabbage

Volume of iodine used in titration =Volume of vitamin C in the boiled white cabbage

a) Calculation of Vitamin C in ascorbic acid (standard)

1mglml of ascorbic acid = 77.00ml iodine solution (during titration)

b) Calculation of Vitamin C in pickles cabbage (Raw 1)

·         Volume of iodine used in the titration of pickled white cabbage  1 turns blue black is 11.5 ml. Compared to the standard volume of vitamin C in the ascorbic acid.

            1mg/ml of vitamin C = 77.00ml of iodine solution

            X mg/ml of vitamin C in pickled cabbage 1= 11.5 ml of iodine solution

            X mg/ml of vitamin C = (11.5ml/77.00ml) x 1 mg/ml

                                                = 0.15 mg/ml

·         Therefore, concentration of vitamin C in the pickled white cabbage is 0.15 mg/ml

·         If 0.15mg/ml of vitamin C in pickled white cabbage = 30 g of cabbage

  

X mg/ml of vitamin C in pickled cabbage= 100g of cabbage

X mg/ml of vitamin C in pickled cabbage = (100g/30g) x 0.15mg/ml

                                                                   = 0.50 mg/ml

Therefore, 100g of pickled white cabbage contain 0.50mg/ml of vitamin C.

c) Calculation of Vitamin C in pickles cabbage (Raw 2)

·         Volume of iodine used in the titration of pickled white cabbage  1 turns blue black is 9.9 ml. Compared to the standard volume of vitamin C in the ascorbic acid.

            1mg/ml of vitamin C = 77.00ml of iodine solution

            X mg/ml of vitamin C in pickled cabbage 1= 9.9 ml of iodine solution

            X mg/ml of vitamin C = (9.9 ml/77.00ml) x 1 mg/ml

                                                = 0.13 mg/ml

·         Therefore, concentration of vitamin C in the pickled white cabbage is 0.13 mg/ml

·         If 0.13 mg/ml of vitamin C in pickled white cabbage = 30 g of cabbage

  

X mg/ml of vitamin C in pickled cabbage= 100g of cabbage

X mg/ml of vitamin C in pickled cabbage = (100g/30g) x 0.13mg/ml

                                                                   = 0.43 mg/ml

Therefore, 100g of pickled white cabbage contain 0.43 mg/ml of vitamin C.

d) Average concentration of Vitamin C in 30g of boiled cabbage

·         (0.15 + 0.13 mg/ml)/ 2 = 0.14 mg/ml

Discussion:

            From the result shown above, we can see that the vitamin C contained in pickled cabbage is less compared to the amount of vitamin C in the raw cabbage. But, the amount of vitamin C contained in the pickled cabbage is larger than vitamin C contained in the boil cabbage. This shows that pickling process causes the vitamin C to moderately loss from the cabbage. Pickling involves the used of vinegar which has lower pH. The lower the pH of solution causes higher concentration of hydrogen ion in the solution which will oxidize the vitamin C in the white cabbage. Thus, the vitamin C will degrades into the solution. The hydrogen ion oxidizes a vitamin C molecules by grabbing one electron from it. The vitamin C then will become dehydroascorbic acid. There are two types of pickling. Fermentation pickles and quick pickled. Fermentation pickles are usually soaked in a highly concentrated salt solution while quick pickled are usually soaked in a highly acidic solution for a short period of time. Fermented pickled allow microorganism to involved in the pickling process. This presence of microorganism reaction causes a greater number of changes due to the activity of the microorganisms and many of the resulting changes appear to be health-supportive. It was found that fat-soluble vitamins such as A, D, E, K are retained during pickling. But, the water soluble vitamin C might be loss in a small amount into the water or solution due to its solubility. 

Conclusion:

Pickling also causes moderate loss of vitamin C due to its water-soluble characteristic. This is due to the higher content of H\hydrogen ions in the lower pH solution which causes the vitamin C to degrades.

 2. Magic writing

Materials:

Beaker

Iodine

Lemon/lime juice

Notebook paper

Cup

Art brush

Procedures:

• Step A

·         Pour 100 ml water into a 500 ml beaker.

·         Add 10 ml of iodine to the water and stir.

• Step B

·         Cut a section from the notebook paper.

·         The paper must fit inside a 500 ml beaker.

• Step C

·         Squeeze the juice of the lemon / lime into another beaker.

• Step D

·         Dip the art brush into the lemon /lime juice.

·         Write a message on the piece of paper.

·         Allow the juice to dry on the paper.

·         Submerse the paper in the iodine solution in the bowl.

 Results:

                                 

Discussions:

Lemon juice is mildly acidic and acid weakens paper. The acid remains in the paper after the juice has dried. When the paper is held near heat the acidic parts of the paper burn or turn brown before the rest of the paper does. Lemon juice is an organic substance that oxidizes and turns brown when heated. Diluting the lemon juice in water makes it very hard to notice when you apply it the paper, no one will be aware of its presence until it is heated and the secret message is revealed. Other substances which work in the same way includes orange juice, honey, milk, onion juice, vinegar and wine. Invisible ink can also be made using chemical reactions or by viewing certain liquids under ultraviolet (UV) light.

Conclusion : 

 Raw white cabbage has highest concentration of Vitamin C compared to boiled and prickled white cabbage. While boiled white cabbage has least Vitamin C because it’s Vitamin C had been altered by heating process. The application for oxidation of acid creates a magic way to be used as ink using lemon juice. 

References :

Fresh Vegetable Growers Of Ontario ( 2007). Vegetable Facts: Cabbage. Retrieved from http://www.freshvegetablesontario.com/index.php?action=display&cat=3&v=9

George Mateljan (2001). How to Cook Cabbage To Preserve Quality. Retrieved from http://whfoods.org/genpage.php?tname=george&dbid=55

Peggy Trowbridge Filippone. Cabbage Health Information. Effects of Cabbage on Your Health. Retrieved from http://homecooking.about.com/od/foodhealthinformation/a/cabbagehealth.htm

http://www.sciencekids.co.nz/experiments/invisibleink.html

     Michael Hutchins. (2011). How Does Boiling Affect Vitamin C Content. Retrieved from http://www.livestrong.com/article/474276-how-does-boiling-affect-vitamin-content/

    Ann Wolters (2011). Does Pickling Process Takes Away The Tutrition? Retrieved from 
http://www.livestrong.com/article/536144-does-pickling-vegetables-take-away-the-nutrition/

   How do pickles compared to cucumbers in terms of nutrition? Retrieve from
http://www.whfoods.com/genpage.php?tname=george&dbid=274

Cham, Eelin Yee Lin. How Changing pH Affects The Rate Of Decomposition Of Vitamin C. Retrieved from
http://www.slideshare.net/wkkok1957/how-changing-ph-affect-the-rate-of-decomposition-of-vitamin-c