A Level: Ethanol Emulsion For Testing Of Fats

Materials:

• Ethanol
• Brownies
• Sticky Rice
• Bread
• Whole
  Bread
• White Bread
• Oil
• Water

Equipments:

• Evaporating Dish
• Test Tube
• Test Tube Rack
• Filter Funnel
• Filter Paper
• Pestle/Mortar
• Pipette
• Tongs

Preparations of a solid sample:

1. Completely crushes adequate amount of food with a clean and dry mortar and pestle.

2. Transfer an adequate amount of crushed food sample to a clean test tube

3. Adds 2cm ethanol above the food sample

4. Shakes the test tube thoroughly and safely .

5. Allows the solid to settle for about 3 min

6. Decants the ethanol carefully into a clean,dry test tube without transference of food particles.

7. Adds 2cm of de-ionized water to the test tube

8. Compares each result with the negative control

9. Compares the heights of the emulsion layer of all the samples

Process:

1. Add the food sample to 2 cm3 of ethanol, shake well.
2. Allow to settle in a test tube rack for 2 minutes for food to dissolve in ethanol.
3. Empty any clear liquid into a test tube containing 2 cm3 of distilled H2O.
4. A MILKY-WHITE EMULSION is a positive result: lipid is present.
5. If the mixture remains clear, there are no fats present in the sample

RESULTS

SUBSTANCE TESTED	PRESENCE OF SPOT	LIPIDS PRESENCE
Brownies	Yes	Yes
Rice	-	-
Sticky Rice	-	-
Cooking Oil	Yes	Yes
White bread	Yes
Whole bread	No	No

By: Nadia Hasna Karimah