Question

Which vitamin would show maximum destruction during Khoa making?

• A. Vitamin B6
• B. Vitamin C
• C. Folic acid
• D. Vitamin A

Hint:

Vitamin Heat Sensitivities in Dairy Processing:
Maximum Destruction during Boiling/Khoa making = VITAMIN C (Ascorbic Acid, $> 90\%$ lost) $>$ Thiamine ($\text{B}_1$) $>$ Folic acid.
Highly Heat Stable = Riboflavin ($\text{B}_2$), Biotin, Vitamin A, Vitamin D.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Thermal degradation kinetics of milk vitamins: prolonged atmospheric boiling and open-pan dehydration during Khoa manufacturing ($> 100^\circ ext{C}$ with continuous scraping) destroys 80--95% of heat- and oxygen-labile ascorbic acid (Vitamin C).
Key Formula or Approach:
\[ \text{Khoa Making: Open Pan Atmospheric Boiling } (100 - 105^\circ\text{C, Intense Aeration}) \implies \mathbf{Vitamin \text{ } C \text{ (Ascorbic Acid) Loss } > 85 - 95\%} \]

Step 2: Detailed Explanation:
In nutritional dairy chemistry and heat processing of indigenous dairy products:
- Khoa (Mawa) is manufactured by continuous thermal evaporation of whole milk in an open shallow iron karahi over direct flame, concentrating total solids to $65 - 72\%$ under intense stirring and atmospheric exposure.
- Vitamin C (L-Ascorbic Acid) (B) is the most thermolabile, oxygen-sensitive, and water-soluble vitamin in milk:
- The combination of prolonged boiling ($100^\circ - 105^\circ ext{C}$ for 30--45 minutes), continuous incorporation of atmospheric oxygen, and catalytic iron ions from the pan causes maximum destruction ($> 85\% - 95\%$ loss) of Vitamin C.
- (In contrast, fat-soluble Vitamin A shows high retention $> 80\%$, and Vitamin $\text{B}_6$ shows moderate retention).

Step 3: Final Answer:
Hence, Vitamin C shows maximum destruction during Khoa making, matching option (B).