High performance size exclusion chromatography analysis (HPSEC) of polar compounds extracted from the lipid fraction of biscuits was able to separate and quantify the different classes of substances formed by to both oxidation (triglyceride oligopolymers and oxidized triglycerides) and hydrolysis (diglycerides) of triglycerides, providing a reliable measure of the quality of edible fats. Mean values in 42 samples were 0.61%, 0.89%, and 4.69% for triglyceride oligopolymers, oxidized triglycerides, and diglycerides, respectively. These results indicated a considerably high extent of hydrolytic and oxidative degradation of the biscuits’ lipid fraction.