Determination of free fatty acids

Question 1

How are free fatty acids liberated from food?

Answer 1

FFAs are produced through the hydrolysis of triglycerides due to the action of temperature and activity of lipases in the presence of water

Question 2

What is acid value?

Answer 2

It is defined as the milligram(Mg) of potassium or sodium hydroxide required to neutralize fatty acids present in 1 gram of fat.
It is a indicative measure of rancidity in fats and oils

Question 3

How to determine acid value in real life?

Answer 3

It is determined by titrating fats and oils in ethanol against standardized potassium hydroxide or sodium hydroxide

Question 4

What did we do in experiment 1 ?

Answer 4

We dissolved measured oil samples in 95% ethanol and 1ml of indicator solution. We boil the mixture in water bath for 5 minutes to make sure oil sample is well dissolved in ethanol. We then titrate against standard sodium hydroxide.

Question 5

How do you calculate acid value of an oil?

Answer 5

(56.1 x V x N)/W
Acid value = %FFA x 1.99
Acid value is expressed in mg
Base volume in ml = V
Normality of base = N
Sample weight in g = W

Question 6

List 2 possible errors that can occur with titration

Answer 6

1. Misjudging the color of the indicator above and below the end point
2. Misjudging the volume of the base due to parallax error

Question 7

Find 3 antioxidants that can be used in fats and oils

Answer 7

Tocopherols
Beta-carotene
BHT (Butylated Hydroxytoluene) Toluene is a CH3 bonded to a aromatic ring

Question 8

How do you calculate N?

Answer 8

N = Weight of Solute (gram) × [Equivalent weight × Volume (L)]

N = Molarity M x Number of proton hydrogen atoms in the chemical formula
For example 36.5 grams of hydrochloric acid (HCl) is a 1 N (one normal) solution of HCl.