In the food field there is an increasing effort to establish objective methods via chemical and physical tests for measuring properties of foods that can be related to human odor and taste sensory properties. In current objective-subjective flavor studies, practically all of the human flavor evaluation techniques have relied upon sensory methods designed to eliminate personal preference judgments. Because of the nature of the information needed for correlation purposes, descriptive sensory analyses appear to be the most satisfactory. The availability in recent years of highly sensitive instruments and newer analytical technologies has proved to be a considerable stimulus to flavor researchers to determine volatile constituents in all manner of fresh and cooked fruits, vegetables, fish, and meat. In most of the work, the analysts have been satisfied to name chemicals found present without attempting to make human response correlation with the food substance under test. While many analytical approaches are being utilized, none has attained the success and degree of use as has the gas Chromatograph coupled with the mass spectrometer. Some literature references describe instances in which good correlation can be made on certain single flavor notes, but not on total flavor. There are some data accumulating on single purified substances in order to determine benefits and limitations of gas chromatography in the odor fractionation and detection field.