In dairy technology, which enzyme treatment is routinely used to improve milk digestibility for lactose-intolerant consumers by hydrolyzing lactose into simpler sugars?

Introduction:Lactose intolerance arises from insufficient intestinal lactase, leading to gastrointestinal discomfort when consuming milk. Industrial processing can pre-hydrolyze lactose to enhance digestibility and sweetness. This question checks knowledge of the specific enzyme used for that purpose.

Given Data / Assumptions:

• Goal: improve digestibility of milk sugars.
• Target substrate: lactose, a disaccharide of glucose and galactose.
• Processing: enzymatic hydrolysis prior to or during consumption.

Concept / Approach:Lactase (β-galactosidase) cleaves the β-1,4 bond in lactose, yielding glucose and galactose. The products are readily absorbed and impart higher perceived sweetness, enabling reduced added sugar in flavored dairy products.

Step-by-Step Solution:Step 1: Identify the digestion barrier: unmetabolized lactose.Step 2: Apply lactase to hydrolyze lactose into monosaccharides.Step 3: Confirm improved digestibility and sensory benefits.Step 4: Select lactase from the options.

Verification / Alternative check:Commercial “lactose-free” milk consistently uses lactase treatment or immobilized lactase reactors to reduce lactose content to near-zero levels.

Why Other Options Are Wrong:

• RNase: Acts on RNA; irrelevant to milk sugar digestion.
• β-amylase: Releases maltose from starch; lactose is not starch.
• none of these: Incorrect because lactase is correct.
• pepsin: A protease acting on proteins; does not hydrolyze lactose.

Common Pitfalls:Confusing proteases or amylases with lactase; forgetting that lactose is a β-galactoside requiring β-galactosidase activity.

Final Answer:lactase