Question

Parboiling leads to:

• A. Nutrient loss
• B. Nutrient migration into grain
• C. Starch hydrolysis
• D. Protein loss

Hint:

Remember: Parboiling = Soaking + Steaming + Drying.
It drives vitamin B-complex from the outer bran deep into the endosperm, which prevents beriberi disease in rice-dependent populations.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks about the primary nutritional or structural outcome of parboiling paddy (rice) before milling.
Parboiling is a hydrothermal process applied to paddy rice, which involves three main stages: soaking, steaming, and drying, prior to the mechanical milling process.

Step 2: Key Formula or Approach:
The approach involves examining the biochemical and physical changes that occur during the parboiling process.
By understanding how moisture and heat interact with the outer layers (aleurone layer, germ, and bran) and the inner core (endosperm) of the rice grain, the nutritional impact of parboiling can be determined.

Step 3: Detailed Explanation:
The key phenomena and effects of parboiling are detailed below:

• Nutrient Migration into Grain: Rice bran and germ are highly rich in water-soluble vitamins (such as Thiamine (\( B_1 \)), Riboflavin (\( B_2 \)), and Niacin (\( B_3 \))) and essential minerals.
During the soaking stage of parboiling, these water-soluble nutrients dissolve in the absorbed water.
During the subsequent steaming stage, the high heat and pressure push these dissolved nutrients deep into the starch-rich endosperm.
As a result, even when the outer bran layer is removed during milling, the milled rice grains retain a significant portion of these essential nutrients.
This is why parboiled rice is highly nutritious compared to raw milled white rice.

• Starch Gelatinization: The starch in the endosperm undergoes gelatinization rather than hydrolysis.
This gelatinization makes the rice grain harder, resulting in a higher yield of head rice (less breakage during milling).
Therefore, "starch hydrolysis" is incorrect (eliminating Option C).

• Reduction of Loss: Because the nutrients are safely locked inside the endosperm, the overall loss of nutrients during subsequent washing and cooking is highly reduced.
Thus, parboiling prevents nutrient loss and protein loss, making Options A and D incorrect.

Step 4: Final Answer:
Hence, parboiling of paddy primarily leads to the migration of water-soluble nutrients into the grain's endosperm.