This document discusses fats and oils. It explains that fats and oils are triglycerides composed of glycerol and long chain fatty acids. It then covers the main reactions of fats and oils including hydrolysis, hydrogenation, and rancidity. The document also outlines several methods for analyzing fats and oils such as acid number, saponification number, iodine number, ester number, Reichert-Meissl number, and acetyl number. These analytical methods are used to determine properties like acid content, ester content, and concentrations of volatile fatty acids.