Question

Separation of liquids from solids by application of pressure is known as:

• A. Extraction
• B. Expression
• C. Rendering
• D. Leaching

Hint:

To remember: "Expression" is like "pressing." You apply pressure to express the liquid out. "Leaching" is like "soaking" where a solvent does the work.

Answer 1

The Correct Option is B

Concept: Solid-liquid separation in food processing can be achieved through mechanical or chemical means.

• Mechanical separation: Uses physical force (pressure).

• Chemical separation: Uses solvents to dissolve the target liquid.

Step 1: Defining Expression.
Expression is the process of squeezing a liquid out of a solid-liquid mixture. It relies entirely on mechanical pressure to rupture cells or compress materials.

Step 2: Identifying common applications.
This method is used in oilseed crushing (screw presses) and sugarcane juice extraction. It is also used to press juice from fruits like grapes or apples.

Step 3: Distinguishing from Leaching.
Leaching (solvent extraction) uses a liquid solvent to "wash out" the oil. Since the question specifies "application of pressure," the correct term is Expression. Final Answer: (B)