Which of the following reagent is used for testing the presence of protein in food?

Explanation

Benedict's reagent is used to test for the presence of reducing sugars in a sample; it is a chemical test that detects the presence of simple carbohydrates with free aldehyde or ketone functional groups, like glucose and fructose. 

Fehling's reagent is used to test for the presence of reducing sugars; specifically, it detects the presence of an aldehyde functional group within a molecule, which is why it can be used to differentiate between reducing and non-reducing sugars like sucrose. 

Millon's reagent is used to test for the presence of tyrosine, an amino acid that contains a phenol group, which is typically found in proteins; a positive reaction with Millon's reagent indicates the presence of tyrosine in a sample. 

Sudan's reagent is used to test for the presence of lipids (fats) in a sample, typically used in food analysis or examining stool samples for fat malabsorption; it works by staining lipids with a dye like Sudan III or Sudan IV, which turns red when it binds to fat molecules. 

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