Question

Match the following physico chemical constants with properties /fatty acid profile of lipids
List I
A. Iodine number
B. Melting point
C. Reichert Meissl
D. Polenske
E. Saponification number
List II
I. Free and esterified
II. Volatile water insoluble
III. Degree of unsaturation
IV. Volatile water soluble
V. Spreadability
Choose the correct answer from the options given below:

• A. A - III, B - V, C - II, D - IV, E - I
• B. A - III, B - V, C - IV, D - II, E - I
• C. A - II, B - IV, C - III, D - I, E - V
• D. A - V, B - III, C - IV, D - II, E - I

Hint:

Remember the volatile fatty acid split: - Reichert-Meissl (RM) $\rightarrow$ Water-soluble volatile fatty acids (Butyric, Caproic) - Polenske $\rightarrow$ Water-insoluble volatile fatty acids (Caprylic, Capric).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Physicochemical constants of lipids are standardized values that reflect the chemical structure, average chain length, and degree of unsaturation of the constituent fatty acids.

Step 2: Detailed Explanation:
Let us match the chemical constants in List I with their corresponding properties in List II:
- A. Iodine number: This value measures the amount of halogen (iodine) absorbed by 100 grams of fat.
It directly indicates the number of double bonds, which represents the Degree of unsaturation (III).
- B. Melting point: The melting point and solid fat content profile of milk fat dictate the physical hardness, crystallization, and Spreadability (V) of products like butter.
- C. Reichert-Meissl (RM) value: This constant measures the milliliters of 0.1N alkali needed to neutralize the steam-volatile, water-soluble fatty acids distilled from 5 grams of fat.
It measures Volatile water-soluble (IV) fatty acids, primarily butyric and caproic acids.
- D. Polenske value: This constant measures the milliliters of 0.1N alkali needed to neutralize the steam-volatile, water-insoluble fatty acids.
It measures Volatile water-insoluble (II) fatty acids, primarily caprylic and capric acids.
- E. Saponification number: This is the milligrams of KOH required to saponify 1 gram of fat.
It represents the average molecular weight of all fatty acids present in both Free and esterified (I) states.
This gives the match: A-III, B-V, C-IV, D-II, E-I.

Step 3: Final Answer
The correct option is (B).