Olive oil, the treasure of Mediterranean

Materials Needed:

• Safety Gear: Gloves, goggles, and aprons

• Ingredients:

  • Olive oil (500 ml)

  • Coconut oil (200 ml)

  • Lye (sodium hydroxide) (100 g)

  • Distilled water (250 ml)

  • Essential oils (optional, for fragrance)

  • Natural colorants (optional, e.g., turmeric, cocoa powder)

• Equipment:

  • Digital scale

  • Heat-resistant glass or stainless steel bowls

  • Stainless steel spoon or spatula

  • Stick blender

  • Soap molds

  • Thermometer

  • Measuring cups and spoons

  • Parchment paper

  • Plastic wrap

  • Labeling materials

  • Divide students into small groups. Have each group measure out the olive oil, coconut oil, lye, and distilled water..Discussion: Explain the role of each ingredient in the soap-making process.

  • Show how to slowly add lye to water (never water to lye) and mix until fully dissolved. Allow the solution to cool to around 100°F (38°C). Have students heat the olive oil and coconut oil mixture to the same temperature (100°F) in a heat-resistant bowl. 

  • Demonstrate how to combine the lye solution with the oils and use a stick blender to blend until "trace" is reached (the mixture thickens and leaves a trail when drizzled on the surface).

  • Optional: Allow students to add essential oils and natural colorants to their soap mixture, stirring thoroughly.

  • Have students pour their soap mixture into molds lined with parchment paper. Show how to smooth the tops and cover the molds with plastic wrap. 

  • Discuss the curing process, explaining that the soap needs to sit undisturbed for 24-48 hours until it hardens enough to unmold. Inform students that the soap will need an additional 4-6 weeks to cure completely, allowing the lye to neutralize fully.

  • In the next day (once it has hardened), demonstrate how to carefully unmold and cut the soap into bars.

  • Optional: Allow students to create labels with the ingredients, date made, and any special notes.

  • Discussion: Reflect on the process, the benefits of olive oil in skincare, and how traditional practices can be integrated into modern routines.

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  • 2. Oil Quality Analysis:

  • Objective: Educate students on the chemical properties and quality indicators of olive oil, by measuring the acidity of different olive oil samples.

  • Materials Needed:

  • Safety Gear: Gloves, goggles, and aprons

  • Chemicals:

  • Phenolphthalein indicator solution

• Sodium hydroxide (NaOH) solution (0.1 N)

• Ethanol

• Equipment:

• Burette

• Burette stand

• Pipette (10 ml)

• Erlenmeyer flask (250 ml)

• Measuring cylinder (100 ml)

• Olive oil samples (extra virgin, virgin, and regular)

• Distilled water

• Calculator

• Notebooks and pens

• Explain what acidity in olive oil means and why it is an important measure of quality. Discuss the different grades of olive oil (extra virgin, virgin, and regular) and their acidity levels, by using the video:

• https://www.youtube.com/watch?v=TaN1CimEqfY

• Divide students into small groups. Have each group set up their burette, ensuring it is clean and free of any air bubbles. Explain the titration process and the role of each chemical used in the experiment.

• Step-by-Step Procedure:

• Measure Olive Oil: Pipette 10 ml of the olive oil sample into an Erlenmeyer flask.

• Add Ethanol: Add 50 ml of ethanol to the flask. This helps dissolve the oil for the titration.

• Add Indicator: Add 2-3 drops of phenolphthalein indicator to the mixture in the flask.

• Titrate: Fill the burette with 0.1 N sodium hydroxide solution. Slowly add the NaOH solution to the flask while constantly swirling until a persistent pink color appears, indicating the endpoint.

• Record Volume: Record the volume of NaOH solution used to reach the endpoint.

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• Calculation:

  • Use the following formula to calculate the acidity: Acidity (%)=[(Volume of NaOH (ml)×Normality of NaOH×28.2)/Weight of olive oil sample (g))]×100

  • Have students calculate the acidity for each sample and compare results across different olive oil types. Compare the calculated acidity levels with the standards for extra virgin, virgin, and regular olive oils. Discuss how acidity affects the flavor, quality, and health benefits of olive oil. 

3. Field Trip

1. Visit to an Olive Oil Mill:

   • Activity: Organize a field trip to a local olive oil mill or invite an olive oil producer to speak to the class.

   • Objective: Provide students with a real-world perspective on olive oil production.

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