Activity 3 laboratory (Final) PDF

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Aivan Karl T. Ambagan

Bachelor of Science in Nursing 1-B ACTIVITY 3 Qualitative Test for Fats and Oils

Theory What are Fats and Oils? Fats and oils are concerted source of energy. Certain percentage of body weight of human being is fat and 20-35% of calories should come from fat. Fats in the diet are essential for good health and are needed for the growth of the body and the processing of vitamins. They make up part of all cells and help to maintain the body temperature. They form fatty tissue around delicate organs to protect them from injury. Chemically fats and oils are triesters of glycerol and higher fatty acids. They are of animal or plant origin. Desi ghee is animal ghee while vanaspati ghee is vegetable ghee. Fats are solids while oils are liquids at ordinary temperature. Fats and oils may be saturated or unsaturated. Saturated fat Saturated fats contain only single bonds within the carbon chain. Saturated fats are of animal origin and are usually present in solid form. It increases the blood cholesterol level. Some examples are meat fat, butter etc. Coconut oil and palm oil also contain saturated fat. Unsaturated fat Unsaturated fats contain double bonds within the carbon chain. Unsaturated fat is found in fish like salmon and tuna, nuts, seeds etc. Some Important Tests for the Detection of Oils and Fats Solubility test Oils and fats are soluble in organic solvents like, chloroform, alcohol etc. but are insoluble in water. Translucent Spot test Fats and oils have higher boiling points so at room temperature they cannot absorb enough heat to evaporate. When fat or oil is place on a sheet of paper, it diffracts light. The diffracted light can pass from one side of the paper to another side and produces a translucent spot. Acrolein test Acrolein test is used to detect the presence of glycerol or fat. When fat is treated strongly in the presence of a dehydrating agent like potassium bisulphate (KHSO 4), the glycerol portion of the molecule is dehydrated to form an unsaturated aldehyde, acrolein that has a pungent irritating odour.

Aivan Karl T. Ambagan

Bachelor of Science in Nursing 1-B

Baudouin test This test is used to detect the presence of seasame oil. Seasame oil gives a characteristic rose red colour with concentrated hydrochloric acid and furfural solution. Vanaspati ghee contains 5% seasame oil while pure desi ghee does not contain seasame oil. So this test can be applied to find out whether the given sample of desi ghee contains vanaspati ghee or not. Huble's test This test is used to detect the degree of unsaturation in oil or fat. Huble’s reagent reacts with alcoholic solution of iodine that contains some mercuric chloride. During the reaction, the violet colour of iodine fades away if the oil or fat is unsaturated. If the oil or fat is saturated, the violet colour of iodine does not fade away.

Aivan Karl T. Ambagan

Bachelor of Science in Nursing 1-B

A. Complete the table below: Procedure: (After watching the video please write what are the procedures in performing the Activity) • •

Prepare all tools, reagents, and record sheet. Wear personal protective equipment.

The following procedures for each test are discussed subsequently. Solubility with Water 1) Take a small quantity of the samples of desi ghee, vegetable ghee, and refined oil in test tubes A, B, and C respectively. 2) Pour small amounts of distilled water in test tubes A, B, and C. 3) Shake each test tube well. 4) Record observations. Solubility with Alcohol 1) Take a small quantity of the samples of desi ghee, vegetable ghee, and refined oil in test tubes A, B, and C respectively. 2) Using a dropper, add few drops of ethyl alcohol into each test tube. 3) Shake each test tube well. 4) Record observations before heating the test tubes. 5) Using the Bunsen burner and triangular tripod stand, heat water inside a beaker. 6) Place the test tubes in a boiling water bath in a beaker. 7) Record observations after the test tubes are heated. Solubility with Chloroform 1) Take a small quantity of the samples of desi ghee, vegetable ghee, and refined oil in test tubes A, B, and C respectively. 2) Using a dropper, pour small amounts of chloroform in test tubes A, B, and C. 3) Shake each test tube well. 4) Record observations. Translucent Spot Test 1) 2) 3) 4) 5)

Using a spatula, take a small quantity of the sample of desi ghee. Transfer it to a filter paper. Press the substance with another filter. Repeat the experiment with vegetable ghee and refined oil. Take the filter papers and place them in front of a lighted candle and move them in front of the flame. 6) Record observations.

Aivan Karl T. Ambagan

Bachelor of Science in Nursing 1-B

Acrolein Test 1) Take a small quantity of the samples of desi ghee, vegetable ghee, and refined oil in test tubes A, B, and C respectively. 2) Using a spatula, add small amounts of potassium bisulfate crystals in test tubes A, B, and C. 3) Using the tongs heat each test tube over the Bunsen burner. 4) Record observations. Baudouin Test 1) Take a small quantity of the samples of melted desi ghee and melted vanaspati ghee in two test tubes A and B respectively. 2) Using a dropper, add small amounts of concentrated hydrochloric acid into the test tubes A and B. 3) Using another dropper, add small amounts of 2% furfural solution in alcohol into the test tubes A and B. 4) Shake the test tubes well and keep them aside for 5 to 10 minutes. 5) Record observations. Huble’s Test 1) Take two test tubes labeled as A and B. 2) Using a dropper, add small amounts of chloroform into the test tubes A and B. 3) Using another dropper, add small amounts of cotton seed oil into the test tube A and linseed oil in test tube B. 4) Shake the test tubes well. 5) Using another dropper, add few drops of Huble’s reagent in each test tube. 6) Record observations. Precautions: • • • •

• • • • • • • • • •

Handle the chemicals with care. Use lab coats and gloves while performing the experiment. Use droppers to take the reagents. Make sure to turn off the Bunsen burner, then clean the tools, dispose reagents properly, and clean the station.

Reagents Distilled water Vegetable ghee Refined oil Ethyl alcohol Chloroform Potassium Bisulfate (KHSO4) crystals Melted desi ghee Melted vanaspati ghee Concentrated HCl 2% Furfural solution in alcohol

Apparatus • • • • • • • • • • •

Test tubes Test tube racks Spatula Candle Tongs/ Test Tube holder Filter paper Bunsen Burner Droppers Beakers Triangular Tripod Stand for Bunsen Burner Bunsen Burner

Aivan Karl T. Ambagan

• • •

Bachelor of Science in Nursing 1-B

Cotton Seed Oil Linseed oil Huble’s reagent

• • •

Tests

Solubility Test with Water

Test Tube A B C

Solubility Test with Alcohol

A B C

Solubility Test with Chloroform

A B C

Translucent Spot Test

A B C

Acrolein Test

A B C

Sample

Safety Gloves Lab gown Safety Goggles

Results Observation

Desi Ghee Vegetable ghee Refined oil

Immiscible Immiscible

Desi Ghee Vegetable ghee Refined oil

Sample forms a lower layer which dissolves on heating. Sample forms a lower layer which dissolves on heating.

Desi Ghee Vegetable ghee Refined oil

Miscible Miscible

Desi Ghee Vegetable ghee Refined oil

Translucent spot appears on the filter paper.

Desi Ghee Vegetable ghee Refined oil

A pungent irritating odour of acrolein.

Immiscible

Sample forms a lower layer which dissolves on heating.

Miscible

Translucent spot appears on the filter paper. Translucent spot appears on the filter paper.

A pungent irritating odour of acrolein. A pungent irritating odour of acrolein.

Baudouin Test

A B

Desi ghee Vanaspati ghee

No formation of rose-red colour. Rose-red colour appears.

Huble’s Test

A

Cotton seed oil Linseed oil

Violet colour does not fade away.

B

Violet colour fade away.

Questions: 1. What is rancidity? Rancidity is a condition in which the substance with oil and fats get oxidized when they are exposed to air. A substance is said to be rancid when there is a change in smell, taste, and color. 2. What reagent was used to test the presence of unsaturation in a given sample of fat or oil?

Aivan Karl T. Ambagan

Bachelor of Science in Nursing 1-B

Huble’s reagent. Huble’s reagent reacts with alcoholic solution of iodine that contains some mercuric chloride. During the reaction, the violet color of iodine fades away if the oil or fat is unsaturated. If the oil or fat is saturated, the violet color of iodine does not fade away. 3. What is acrolein? Acrolein is a substance mostly used to make acrylic acid. It is also used to control plant and algae growth in irrigation canals. Acrolein kills or controls microorganisms and bacteria in oil wells, liquid hydrocarbon fuels, cooling-water towers and water treatment ponds. In papermaking, acrolein is used to control slime.

4. Rose red colour appears when vanaspati ghee is subjected to Baudouin test. What does it indicate? Rose-red color is formed due to the presence of sesame oil. Thus, it indicates that vanaspati ghee contains sesame oil whereas pure desi ghee does not contain sesame oil. So, this test is used to distinguish between desi ghee and vanaspati ghee.

Conclusion: Qualitative tests for fats and oils are used to identify the presence, chemical properties, solubility, and reactivity of fats and oils with other substances. For instance, in the solubility test with water, all samples are immiscible which indicate that oil or fat is present in the solution. Substances in alcohol that form a lower layer which dissolve in heating shows the presence of oil or fat. In the solubility with chloroform, samples that are miscible also reflect the existence of oil or fat in the solution. Moreover, since fat and oil have the ability to diffract light, the appearance of translucent spot on the filter paper indicates the presence of oil or fat in the translucent spot test. A pungent irritating odour of acrolein confirms the presence of oil or fat in the Acrolein test. On the other hand, Baudouin test helps distinguish between desi ghee and vanaspati ghee. Finally, the Huble’s test is used to detect the degree of unsaturation in oil or fat. In the experiment the sample with cotton seed oil does not fade away its violet color. Hence, it is saturated. The different chemical tests explored in this laboratory have specific reactions designed to identify, characterize, and qualify fats and oils....