Question

Packaging of khoa at __________ °C extends its shelf life to 14-21 days at 37 °C.

• A. 40-50
• B. 80-90
• C. 60-70
• D. 50-60

Hint:

Hot packaging of traditional dairy products like Khoa or Chhana-podat must be carried out above the thermal death point of common vegetative molds and yeasts, which is why temperatures of \(80\text{--}90^\circ\text{C}\) are preferred.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Khoa is a traditional Indian heat-desiccated dairy product.
Because it contains significant moisture and nutrients, it is highly susceptible to mold growth, yeast fermentation, and bacterial spoilage when stored at ambient temperatures (\(37^\circ\text{C}\)).
"Hot packaging" is a preservation technique designed to prevent post-processing contamination.

Step 2: Detailed Explanation:
During the final stages of Khoa making, the milk is boiled down to a semi-solid paste.
At this point, the product is practically sterile due to the high processing temperatures.
However, as it cools down, exposure to air, equipment, and packaging materials can introduce yeast and mold spores.
If Khoa is packaged while still hot, at \(80\text{--}90^\circ\text{C}\), in suitable laminate pouches:
- The high heat of the product pasteurizes the inner surfaces of the packaging material.
- It eliminates any vegetative yeast and mold cells that may have settled on the product surface during handling.
- It expels residual oxygen from the pouch, creating a partial vacuum after cooling, which further inhibits aerobic molds.
This hot-packaging technique effectively extends the shelf life of Khoa to 14--21 days even at a warm incubation temperature of \(37^\circ\text{C}\).
In contrast, cold-packaged Khoa (packaged at \(30\text{--}40^\circ\text{C}\)) spoils within \(3\text{--}5\) days under similar conditions.

Step 3: Final Answer:
Packaging Khoa at a high temperature range of \(80\text{--}90^\circ\text{C}\) is required to extend its shelf life.