Acid value

1. Acid Value
Definition, Formula, Procedure &
Applications

2. Definition
• • Acid value is the number of mg of KOH
required to neutralize the free fatty acids
present in 1 g of fat or oil.
• • It is an important parameter in food,
cosmetic, and lubricant industries to
determine the quality and freshness of
oils/fats.

3. Formula
• Acid Value = (V × N × 56.1) / W
• Where:
• V = Volume of KOH used (mL)
• N = Normality of KOH
• 56.1 = Molecular weight of KOH
• W = Weight of sample (g)

4. Procedure (Titration Method)
• 1. Weigh a known amount of oil/fat sample.
• 2. Dissolve in ethanol-ether mixture.
• 3. Add phenolphthalein indicator.
• 4. Titrate with standard KOH solution.
• 5. Note the volume of KOH used.
• 6. Calculate acid value using formula.

5. Applications
• • To assess the freshness of edible oils.
• • To check rancidity in fats and oils.
• • Used in cosmetic industry for oil quality
control.
• • In lubricants, high acid value indicates
degradation.

6. Conclusion
• • Acid value is a key parameter for
determining the quality of oils and fats.
• • Lower acid value indicates better quality and
freshness.
• • Regular monitoring ensures safety and
stability of products.