Question

1. which of the following would test positive in the biuret test, and negative in the sudan red test? skim milk wheat bread meatloaf vegetable oil

Explanation:

The Biuret test detects proteins, while the Sudan Red test detects lipids (fats).

• Skim milk has high protein content and minimal fat, so it tests positive for Biuret and negative for Sudan Red.
• Wheat bread is mostly carbohydrates, so it tests negative for both.
• Meatloaf contains both protein and fat, so it tests positive for both.
• Vegetable oil is pure lipid, so it tests positive for Sudan Red and negative for Biuret.

Answer:

skim milk