if you wanted to test a piece of food to see if it contained protein which chemical would you use?

To test a piece of food for protein, the chemical commonly used is the Biuret reagent, which is a solution made by combining sodium hydroxide (NaOH) and copper sulfate (CuSO4). When this reagent is added to a food sample containing protein, it reacts with the peptide bonds in the protein, producing a violet or purple color. This color change indicates the presence of protein in the sample. The Biuret test involves mixing the food sample with distilled water, adding sodium hydroxide solution, then adding a few drops of copper sulfate solution. If the solution turns violet or purple, it confirms protein presence. Thus, the Biuret reagent is the key chemical for testing protein in food.