ABSTRACT
The analysis of flavors is challenging for various reasons: flavors are complex mixtures of volatile molecules with sensory properties. They occur only in small amounts in a wide range of natural products with different matrix compositions (including fat, protein, carbohydrates, water, minerals, and active enzymes). Flavors and flavoring molecules are prone to chemical and physical alterations such as evaporation, contamination, oxidation, degradation, and enzymatic and intermolecular reactions. All volatile molecules do not contribute equally to the overall flavor profile. An analytical flavor chemist therefore needs extensive knowledge, skills, and tools to isolate the traces, separate the mixture, identify the molecules, and validate the sensory properties. Developments in the last 30 years have made this task manageable and a matter of routine [1-4]. Methods and microtechniques are available to isolate flavors from small samples such as single fruits during a ripening process without destroying the fruit [5]. High-resolution capillary gas chromatography combined with sensitive, fast mass spectrometers allow efficient separation and identification of volatile molecules out of complex mixtures, based on reliable, complete mass spectral databases. Suitable equipment is commercially available. Quanti-fication is simplified by the use of stable isotope derivatives of the key components [6]. Training in sensory evaluation has been drastically improved, using standardized descriptive languages and quantitative flavor profiling [7]. Gas chromatography (GC) sniffing is widely used to recognize and quantify key impact molecules [8-10]. Yet, there are still skills and tools to improve:
Identify the critical steps in analyzing flavors. Link analytical and sensory results. Handle rare and complex samples.
