Question

When milk is heated, the development of brown colour is due to non-enzymatic browning called?

• A. Malting reaction
• B. Maillard reaction
• C. Gelatinisation reaction
• D. Dextrinisation reaction

Hint:

Protein + Reducing Sugar + Heat = Maillard Reaction. It's why bread crusts, roasted meat, and boiled milk turn brown and smell delicious.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to identify the specific chemical reaction that causes milk to turn brown when subjected to heat, such as during the making of condensed milk or khoya.

Step 2: Detailed Explanation:

• Browning in food is categorized as enzymatic (caused by enzymes like polyphenol oxidase) or non-enzymatic.

• In milk, the non-enzymatic browning occurs due to the interaction between the amino acids of milk protein (casein and whey) and the reducing sugar (lactose).

• This specific chemical interaction is called the Maillard reaction. It produces melanoidins, which are brown pigments, and develops the characteristic cooked flavor.

• Caramelization is another type of non-enzymatic browning, but it involves only sugars heated to high temperatures without proteins.

• Gelatinization (C) refers to starch granules swelling in water. Dextrinization (D) is the breakdown of starch into dextrins by dry heat. Malting (A) is a biological process in grains.

Step 3: Final Answer: The browning of milk upon heating is due to the Maillard reaction.