FUN EXPERIMENT 5: Lipid

Abstract:

Saponification number primarily serves to determine the proportion of fatty acid esters in the sample. Saponification number also used as an indicator to fatty acid chain length in triglyceride. This number can be measured by the concentration of KOH used to complete the hydrolysis of one gram of fat or oil. Triglycerides containing high fatty acid number will have a lower saponification number than triglycerides with low fatty acids number. In this experiment, corn oil were used as a sample of triglycerides. From the experiment, corn oil shows higher saponification number which is meant corn oil have lower fatty acid chain in triglycerides.The application of using lipid is by making soap. Soap is known as an excellent emulsifier due to its amphipathic structures molecules where it has hydrophilic head group and hydrophobic portion group. This structure becomes nonpolar hydrocarbon portion of the micelled that will break up the nonpolar dirt/grease molecule. 

Introduction:

Triglyceride is an ester composed glycerol and three fatty acids. It is a blood lipid that helps bidirectional transference of adipose fat and blood glucose from liver. There two categories of triglycerides; saturated and unsaturated. Saturated compounds contain high amount of hydrogen in the molecule. Meanwhile unsaturated compounds contain double bonds between the carbon atoms (C=C) which reduce the number of places where hydrogen atoms can bond to carbon atoms. Saponification is the process of making soap. Meanwhile, saponification number which  also referred as “sap” shows the number of potassium hydroxide required in milligrams to saponify 1 g of fat under specified condition.

1) Saponification of triglycerides

Procedure:

Results: 

Discussion:

           Saponification number is a measure of the total free and combined acids especially in a fat, wax, or resin expressed as the number of milligrams of potassium hydroxide required for the complete saponification of one gram of substance. Throughout this experiment, corn oli have higher saponification number compared to palm oil. According to Lewkowitsch (1922), the actual saponification number of palm oil is higher than the number of saponification in corn oil. The actual saponification of corn oil is between 188-193 mg while saponification number of palm oil is in range between 196-205 mg. The high saponification number of corn oil is due to the large proportion of lauric acid and myristic acid that they contain. According to Niir Board (2002), oleic acid and linoleic acid usually comprise over 80% of the fatty acids in a ratio 1:2 – 1:3. Linoleic acid is either absent or present in traces. Palmitic acid is the main saturated fatty acid (10%). The triglycerides are mainly di- and triunsaturated. 
         In this experiment, The difference in the molar amount of HCl used to neutralize the control and the amount of HCl used to neutralize the sample equivalent to the molar amount of KOH used to saponify the test sample because one mole of HCl reacts with one mole of KOH. Thus, the test sample requires more acid to neutralize it because it contains more alkali than the control. Since the ratio concentration of HCL and KOH is 1:1 reaction, so the moles of KOH and HCl are equivalent.

Conclusions:

In a conclusion, the highest saponification number in corn oil indicates its fatty acid chain length in triglyceride is lower.




2) Application: Making soap


Procedure: 

Corn Oil weighted

NaOH added

Results:

Soap 1

Soap 2

Discussion: 

            In this experiment, we used corn oil to make soap. Soaps are mixtures of sodium or potassium salts of fatty acids which can be derived from oils or fats by reacting them with an alkali (such as sodium or potassium hydroxide) at 80°–100 °C in a process known as saponification. Each soap molecule has a long hydrocarbon chain, sometimes called its 'tail', with a carboxylate 'head'. In water, the sodium or potassium ions float free, leaving a negatively-charged head.

Soap is known as an excellent cleanser because of its ability to act as an emulsifying agent. An emulsifier is capable of dispersing one liquid into another immiscible liquid. This means that while oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed. Soap can act to disperse dirt/grease by its amphipathic molecules structure because it has a hydrophilic head group and hydrophobic portion. The organic part of a natural soap is a negatively-charged, polar molecule. Its hydrophilic (water-loving) carboxylate group (-CO₂) interacts with water molecules via ion-dipole interactions and hydrogen bonding. The hydrophobic (water-fearing) part of a soap molecule, its long, nonpolar hydrocarbon chain, does not interact with water molecules. The hydrocarbon chains are attracted to each other by dispersion forces and cluster together, forming structures called micelles. In these micelles, the carboxylate groups form a negatively-charged spherical surface, with the hydrocarbon chains inside the sphere. Because they are negatively charged, soap micelles repel each other and remain dispersed in water.

Grease and oil are non polar and insoluble in water. When soap and soiling oils are mixed, the non polar hydrocarbon portion of the micelles break up the nonpolar oil molecules. A different type of micelle then forms, with non polar soiling molecules in the center. Thus, grease, oil and the 'dirt' attached to them are caught inside the micelle and can be rinsed away.

           In saponification, boiling the oil (triglycerides) will react with alkali (potassium hydroxide) to produce glycerol and fatty acids salts. Triglycerides exist in the organic phase while the hydroxide exists in the aqueous phase. By increase stirring, the reactants will happen to be in the same phase. Therefore, the oils can be hydrolyzed to form glycerol and fatty acid salts. So, glycerol and fatty acid salts which having distance different solubility in both phases can be formed. The reagent will increase in concentration in the phase which is most favored by the other as the reaction progress.

Conclusion:

Soap can act to disperse dirt/grease by its amphipathic molecules structure where it has a hydrophilic head group and hydrophobic portion. This structure becomes nonpolar hydrocarbon portion of the micelled that will break up the nonpolar dirt/grease molecule. 

Reference:

1. Anne Marie Helmenstine. How Soap Cleans, Soap is an Emulsifier. Retrieved from   

             http://chemistry.about.com/od/cleanerchemistry/a/how-soap-cleans.htm

2. Structure of Lipids. Retrieved from http://dwb.unl.edu/Teacher/NSF/C10/C10Links/mills.edu/RESE 

           ARCH/FUTURES/JOHN B/struct urefunction/724.html

3.  Soap. Retrieved from http://www.chemistryexplained.com/Ru-Sp/Soap.html

4. Lewkowlts, J.(1922). Chemical Technology and Analysis of Oils,Fats and Waxes. London, Macmillan. 

             Retrieved from http://www.journeytoforever.org/biofuel_library/fatsoils/fatsoils2.html

5. Niir Board (2002). Oils, Fats & Its Derivatives. Delhi : Asia Pacific Business Press Inc. Retrieved from      http://books.google.com.my/booksid=rChwMIJHdE8C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

6. Triglycerides. Retrieved from http://en.wikipedia.org/wiki/Triglyceride

7. Saponification value. Retrieved from http://en.wikipedia.org/wiki/Saponification_value

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