Which procedure would be part of a laboratory investigation designed to determine if a specific nutrient is present in a food?

A common procedure to determine if a specific nutrient is present in a food is to use qualitative tests specific to that nutrient. For example, to test for starch, you would add iodine solution to the food sample; a blue-black color indicates the presence of starch. For proteins, the Biuret test can be employed, where a violet color change signifies protein presence. Additionally, for reducing sugars, a Benedict's test can be conducted, with a color change indicating the presence of sugars.