Question

First unit operation in oil refining process is

• A. Blanching
• B. Winterization
• C. Deodorization
• D. Alkali treatment

Hint:

Refining sequence: Degumming $\rightarrow$ Alkali Neutralization $\rightarrow$ Bleaching $\rightarrow$ Winterization $\rightarrow$ Deodorization.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Chemical refining of crude vegetable oils involves sequential purification operations to remove phospholipids, free fatty acids (FFA), pigments, waxes, and volatile odorants.

Step 2: Detailed Explanation:
The standard sequence of unit operations in edible oil chemical refining is:
1. Degumming: Removal of hydratable phospholipids.
2. Alkali Refining Neutralization (Alkali treatment): Addition of sodium hydroxide (NaOH) solution to convert free fatty acids into insoluble soapstock.
3. Bleaching: Adsorption of pigments using activated bleaching clay.
4. Winterization Dewaxing: Crystallization and filtration of high-melting waxes.
5. Deodorization: High-temperature steam vacuum distillation to remove volatile odoriferous compounds.
Among the listed options, Alkali treatment is the first primary chemical refining operation.

Step 3: Final Answer:
Therefore, the first unit operation among the options is Alkali treatment, corresponding to option (D).