Biomolecules Identification in Food Samples

Biomolecules Identification

• Identifying biomolecules in 10 food samples using different reagents:
  • Iodoform test for starch
  • Vibri reagent for proteins
  • Fehling and PeLienk reagents for reducing sugars
  • Sudan 3 and vegetal dye for lipids

Starch Identification

• Iodoform test:
  • Add 2-3 drops of iodoform reagent to each tube
  • Shake the tubes well
  • Observe color change:
    • Positive result: blue-black color (starch present)
  • Results:
    • Tube 6 (potato): positive result
    • Tube 7 (sausage): positive result
    • Tube 8 (starch): positive result
    • Tube 9 (milk powder): positive result

Protein Identification

• Vibure reagent:
  • Add 5 drops of Vibure reagent to each tube
  • Shake the tubes well
  • Observe color change:
    • Positive result: purple color (proteins present)
  • Results:
    • Tube 4 (egg white): strong positive result
    • Tube 2 and Tube 7: weaker positive results
    • Milk and milk powder: may contain proteins, but white color masks the purple color

Reducing Sugars Identification

• Fehling and PeLienk reagents:
  • Add 5 drops of Fehling's reagent to each tube
  • Add 5 drops of PeLienk reagent to each tube
  • Observe color change:
    • Positive result: red brick color (reducing sugars present)
  • Results:
    • Tube 3 (glucose): strong positive result

Lipid Identification

• Sudan 3 and vegetal dye:
  • Add 1 mL of vegetal dye to each tube
  • Add 3 drops of Sudan 3 to each tube
  • Observe color separation:
    • Positive result: Sudan 3 mixes with lipids, while vegetal dye stays at the bottom
  • Results:
    • Tube 10 (oil): Sudan 3 mixes with lipids, while vegetal dye stays at the bottom

Biomolecules Identification

• 4 types of biomolecules identified in 10 food samples using different reagents
• Reagents used: iodoform, Vibure, Fehling, PeLienk, Sudan 3, and vegetal dye

Starch Identification

• Iodoform test detects starch
• Procedure: add 2-3 drops of iodoform reagent, shake, and observe color change
• Positive result: blue-black color indicates starch presence
• Results: starch present in Tubes 6 (potato), 7 (sausage), 8 (starch), and 9 (milk powder)

Protein Identification

• Vibure reagent detects proteins
• Procedure: add 5 drops of Vibure reagent, shake, and observe color change
• Positive result: purple color indicates protein presence
• Results: strong positive result in Tube 4 (egg white), weaker positive results in Tubes 2 and 7

Reducing Sugars Identification

• Fehling and PeLienk reagents detect reducing sugars
• Procedure: add 5 drops of Fehling's reagent and 5 drops of PeLienk reagent, observe color change
• Positive result: red brick color indicates reducing sugar presence
• Results: strong positive result in Tube 3 (glucose)

Lipid Identification

• Sudan 3 and vegetal dye detect lipids
• Procedure: add 1 mL of vegetal dye and 3 drops of Sudan 3, observe color separation
• Positive result: Sudan 3 mixes with lipids, while vegetal dye stays at the bottom
• Results: positive result in Tube 10 (oil)