Question

The most common shape of lactose crystal is

• A. Pyramid
• B. Tomahawk
• C. Rhomboid
• D. Globular

Hint:

Lactose Crystal Geometry:
$\alpha$-Lactose Monohydrate = TOMAHAWK Hatchet shape ($< 93.5^\circ\text{C}$).
$\beta$-Lactose Anhydrous = Needle Kite shape ($> 93.5^\circ\text{C}$).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Crystallography of lactose monohydrate: $lpha$-lactose monohydrate crystallizes from supersaturated aqueous solutions in a characteristic prism shape resembling a Native American tomahawk (hatchet).
Key Formula or Approach:
\[ \text{Supersaturated Lactose Solution } (T < 93.5^\circ\text{C}) \longrightarrow \alpha\mathbf{\text{-Lactose Monohydrate Crystal [Tomahawk / Axe Shape]}} \]

Step 2: Detailed Explanation:
In dairy carbohydrate physical chemistry and crystallography:
- Lactose exists in two principal anomeric crystal forms: $\alpha$-lactose monohydrate (crystallizing below $93.5^\circ ext{C}$) and anhydrous $\beta$-lactose (crystallizing above $93.5^\circ ext{C}$).
- In supersaturated dairy products (Sweetened Condensed Milk, Ice Cream, concentrated whey):
- $\alpha$-Lactose Monohydrate crystals grow with asymmetrical face velocity along the c-axis, developing a pathognomonic Tomahawk Shape (Hatchet Axe-head shape) (B).
- If crystal size exceeds $10 - 15\;\mu\text{m}$, these hard, sharp tomahawk crystals cause the sensory defect of 'Sandiness' in sweetened condensed milk and ice cream.

Step 3: Final Answer:
Therefore, the most common shape of lactose crystal is Tomahawk, corresponding to option (B).