Question

Which of the following is not true regarding aluminium as food packaging?

• A. No taste and odour
• B. Produce sulfide staining
• C. Excellent workability
• D. Light weight

Hint:

To prevent sulfide staining in tinplate cans, lacquers like C-emel (containing zinc oxide) are applied, which react to form white zinc sulfide instead of black iron/tin sulfide.
Aluminium turally avoids this staining because its sulfides do not form dark deposits on the surface under standard retort processing.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Aluminium is a widely used material in the food packaging industry due to its unique barrier properties, mechanical strength, and physical characteristics.
It is commonly utilized in the form of foil, lamited pouches, beverage cans, and aerosol containers.
Understanding the advantages and chemical limitations of metal packaging materials is critical for selecting the appropriate package for specific food types.

Step 2: Detailed Explation:
Aluminium possesses several outstanding properties that make it highly desirable for food packaging.
First, it is completely non-toxic, imparting no taste or odor to the packaged food, preserving the sensory quality of the food product.
Second, it has low density (\(2.7 \text{ g/cm}^3\)), making it extremely lightweight compared to tinplate or glass, which minimizes transportation costs.
Third, it has excellent workability and ductility, allowing it to be easily rolled into thin foils or shaped into complex can designs.
However, unlike steel or tinplate cans, aluminium does not produce sulfide staining when exposed to sulfur-containing foods.
Sulfide staining (typically the formation of dark iron sulfide or tin sulfide) is a well-known cosmetic defect occurring in tinplate cans containing high-protein foods like meats, fish, and poultry.
Aluminium does not react with hydrogen sulfide to form black precipitates under normal processing conditions.
Therefore, the statement that aluminium produces sulfide staining is incorrect, making it the correct choice for this question.

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