Question

Which one of the following is not fining agents used in clarification of fruit juices?

• A. Gelatin
• B. Albumen
• C. Sorbitol
• D. Casein

Hint:

Remember that most traditiol fining agents are proteins (Gelatin, Casein, Albumen, Isinglass) or mineral clays (Bentonite) that interact via electrostatic forces and hydrogen bonding.
Sorbitol is purely a carbohydrate-derived additive used for sweetening and texture.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Clarification is an essential step in fruit juice processing aimed at removing suspended solids, pectins, and polyphenolic compounds that cause turbidity and haze.
Fining agents are substances added to the juice to bind with these haze-causing elements and form insoluble complexes that can be easily removed by filtration or centrifugation.
Key Principle:
Effective fining agents are typically polymeric or proteiceous molecules that carry electrical charges, allowing them to electrostatically bind to oppositely charged colloidal particles in the juice.

Step 2: Detailed Explation:
Gelatin is a positively charged animal protein that easily binds with negatively charged tannins and polyphenols to form large flocs.
Albumen (egg white protein) and Casein (milk protein) are also proteiceous agents used to remove phenolic substances and suspended proteins.
Sorbitol is a polyol (sugar alcohol) commonly used as a humectant, sweetener, and texturizer in sugar-free foods.
Sorbitol does not carry the necessary macromolecular structure or electrical charges to react with suspended solids or polyphenols.
Consequently, it cannot act as a clarification or fining agent in juice processing.

Step 3: Fil Answer
Sorbitol is the correct answer because it is a low-molecular-weight sugar alcohol and lacks any clarifying properties.