Denise Farmoz explains various food tests, detailing the processes and apparatus involved. The lesson covers the Biuret test for proteins, Benedict’s solution for reducing sugars like glucose, iodine for starch, and ethanol for fats. The step-by-step procedures demonstrate how to identify the presence of food biomolecules, with specific color changes indicating positive results, such as the blue-black color for starch when using iodine.