Volatile compounds are low-molecular-weight components that can naturally occur in raw food material as well as develop during food processing, i.e., roasting, smoking, baking, fermentation, and aging. They significantly contribute to food sensorial properties in terms of aroma and flavor characteristics and play an important role in consumer acceptance and appreciation of foods. On the other hand, unwanted chemical and microbiological changes also yield off-odor compounds that can be used as a spoilage indicator in foods. The following chapter describes quantitation and aroma profile screening methods for the volatile compounds with gas chromatography flame ionization detector (GC-FID) and gas chromatography mass spectroscopy (GC-MS).