Lab Report 3: Triglyceride

INTRODUCTION

Triglycerides are fat in the blood. They are used to give energy to our body. If it is excess, they are stored in different places, to be used later. They are important to life and are the main form of fat, called lipids in the body. They are the end product of digesting and breaking down fats in food. Some are made in the body from other energy sources such as carbohydrates. 

But high triglycerides might raise your risk of heart disease and may be sign of metabolic syndrome. Metabolic syndrome is the combination of high blood pressure, high blood sugar, too much fat around the waist, low HDL and high triglycerides. 

 Vegetable oils and animal fats are the main materials that are saponified. These greasy materials, triesters called triglycerides are mixtures derived from diverse fatty acids. triglycerides can be converted to soap in either one or two step process. 

MATERIALS

Triglyceride sample (coconut oil, corn oil, palm oil, margarine, butter) solvent (1:1 ethanol/ether), 0.5M KOH/ethanol solution, phenolphtalein, 0.5M HCl.

PROCEDURE

1. 1.0 g sample triglyceride was placed into a small beaker and dissolved in 4 ml solvent(1:1 ethanol /ether).

2. Dissolved triglyceride was transferred into a small distillation flask and beaker wshed twice with 1 ml solvent to collect all residual material. “wash” also added to the distillation flask.

3. 25 ml of 0.5 M KOH/ethanol solution was added.

4. Exact volume of the mixture was measured.

5. Second system as “control” was set up with 25 ml 0.5 M KOH/ethanol solution + 2 ml of 1:1 ethanol/ether solvent for a final volume identical to our test sample solution.

6. Reflux condenser was set up on each flask and boiling water bath was placed in for 30 minutes. Hydrolysis occur.

7. Flask allowed to cool. Three drops indicators (phenolphthalein) was added to both flasks and titrated with 0.5 ml HCl solution.

RESULT

Sample
B (ml)
T (ml)
Saponification number (mg KOH/1g)
Palm oil
23.00
22.00
28.06 mg KOH/1g
Sunflower
22.20
21.00
33.67mg KOH/1g
Corn oil
23.00
22.00
28.06mg KOH/1g
Margerin
23.00
20.00
84.17mg KOH/1g
Butter
28.00
25.00
84.17mg KOH/1g

DISCUSSION

The saponification number (sap) measures the bonded and unbonded acids present in an oil or fat. It defines the exact amount of potassium hydrate in mg necessary to emulsify 1g of fat or oil.  The smaller the molar mass of the fat, the higher the saponification value. For saponification of triglycerides experiment to determine the saponification number of triglycerides, we were using palm oil as a sample for our group. Different group used different lipid which are sunflower oil, corn oil, margarine and butter. Then at the end of the experiment we obtained the final results for each sample. Based on the results obtained, sunflower oil has the higher saponification number between oil which is 33.67 mg KOH/1g compared to corn oil and palm oil which has the same value at 28.06 mg KOH/1g. So it shown that, sunflower oil has shorter fatty acids. However, margarine and butter has the highest saponification number at 84.17 mg KOH/1g. It is because Fats and oils can be characterized by their saponification numbers. One mole of fat requires three moles of potassium hydroxide for complete saponification. If a fat contains fatty acids of relatively high molecular weights, then one gram of the fat will consist of fewer moles. Thus, fats having greater percentages of high molecular weight fatty acids will have lower saponification numbers than fats having greater percentages of lower molecular weight fatty acids.
Theory said that triglycerides containing long fatty acids will have a lower saponification number than triglycerides with shorter fatty acids. Since 1 gram of lipid containing long chains will have less chains in total than 1 gram of lipid containing short chains. Actually, we should get the higher saponification number for palm oil followed by corn oil and the lowest is sunflower oil.  Low fatty acid fats like coconut oil or palm kernel fat have high saponification numbers of 250, whereas most vegetable oils have a saponification number of approximately 190 It means that, palm oil have the shorter fatty acid chain than corn oil and sunflower oil. For the palm oil and corn oil, the saponification number should higher than sunflower oil because they have shorter fatty acid chain than sunflower oil. A few error occur during the experiment that effect the results obtained that are, there is no standard colour of solution when turns colourless. The pinkish colour might still there. So, this affect the titration process. It then, affect the volume of HCl used.

CONCLUSION

 From this experiment, we are able to calculate the saponification number (mg KOH/1g) and can differentiated which fats or oil that containing high fatty acid number based on their saponification number.

 REFERENCES

 1. http://www.chemistryexplained.com/Di-Fa/Fats-and-Fatty-Acids.html#ixzz4gYl8E55s
2. https://en.m.wikipedia.org/wiki/Saponification
3. www.webmd.com/cholestrol-management/tc/high-triglycerides-overview