Determination of Free Fatty Acids (FFA)
Objective
To determine the free fatty acid content in oils and fats through titration method.
Materials Required
- Burette (50 mL)
- Pipette (25 mL)
- Conical flask (250 mL)
- Analytical balance
- Sodium hydroxide (NaOH)
- Phenolphthalein indicator
- Ethanol (95%)
Solution Preparation
1. 0.1N NaOH Solution
- Weigh 4.0 g NaOH pellets
- Dissolve in 500 mL distilled water
- Standardize using potassium hydrogen phthalate (KHP)
2. Neutral Ethanol Solution
- Mix 95% ethanol with equal volume of distilled water
- Add 1 mL phenolphthalein indicator
- Neutralize with 0.1N NaOH until faint pink color appears
3. Phenolphthalein Indicator
- Dissolve 1 g phenolphthalein in 100 mL 95% ethanol
Procedure
- Weigh 5±0.2 g oil sample into conical flask
- Add 50 mL neutral ethanol
- Heat gently to dissolve (60-70°C)
- Titrate with 0.1N NaOH while hot
- Endpoint: Persistent pale pink color (30 seconds)
Calculation
FFA % (as oleic acid) = (V × N × 282) / (10 × W)
Where:
V = Volume of NaOH used (mL)
N = Normality of NaOH
W = Sample weight (g)
Safety Precautions
- Wear PPE (lab coat, gloves, goggles)
- Handle NaOH with care – corrosive!
- Ethanol is flammable – no open flames
Note: All glassware must be properly cleaned and dried before use.
Store NaOH solutions in plastic containers.
Free fatty acids (FFAs)
Free fatty acids (FFAs), also known as non-esterified fatty acids (NEFAs), are fatty acids that are not bound to glycerol (unlike triglycerides or phospholipids). They circulate in the blood, primarily bound to albumin, and serve as a critical energy source, metabolic regulator, and signaling molecule.
Sources of Free Fatty Acids
FFAs are released from:
- Adipose tissue (via lipolysis of stored triglycerides).
- Dietary fat digestion (breakdown of triglycerides in the gut).
- Lipoprotein lipase (LPL) activity (hydrolysis of circulating triglycerides in chylomicrons & VLDL).
Regulation of FFA Levels
| Factors Increasing FFAs | Factors Decreasing FFAs |
|---|---|
| Fasting/starvation | Insulin (suppresses lipolysis) |
| Exercise | High-carbohydrate diet |
| Stress hormones (catecholamines, cortisol) | Antilipolytic drugs (e.g., niacin) |
| Low insulin (e.g., diabetes) | Omega-3 fatty acids |