50 years of mass spectrometry at Firmenich: a continuing love story.

Mass spectrometry (MS) has been intensively used in the field of flavor and fragrance since its beginning in the 1950s, and it remains an essential technique for current and future research in this field. After a short historical section on the introduction and development of MS at Firmenich, this work reviews the main applications of MS-based techniques published by Firmenich researchers over the past 5 years. It exemplifies the use of gas chromatography (GC)-MS for the discovery of new odorant - hence volatile - molecules in a broad range of natural products, such as fruits, meats, and vegetables. Non-volatile compounds play a major role in taste attributes and are also possible precursors of odorant molecules. Their identification by liquid chromatography (LC)-MS in the context of malodor generation from sweat is a typical example of such a relationship. With their high selectivity and sensitivity, GC-MS and LC-MS instruments are used in the fields of flavor and fragrance not only for identification, but also as unique tools for the accurate quantitation of compounds in complex matrices. This is particularly important for regulatory analyses such as dosage of potential allergens in perfumes and for the development of delivery systems. Finally, because of the rapid response time of MS, the kinetics of processes such as the release of flavors in the mouth during food consumption can be monitored by direct sampling into the mass spectrometer.

Qualitative and quantitative analysis of volatile constituents from latrines.

More than 2.5 billion people defecate in the open. The increased commitment of private and public organizations to improving this situation is driving the research and development of new technologies for toilets and latrines. Although key technical aspects are considered by researchers when designing new technologies for developing countries, the basic aspect of offending malodors from human waste is often neglected. With the objective of contributing to technical solutions that are acceptable to global consumers, we investigated the chemical composition of latrine malodors sampled in Africa and India. Field latrines in four countries were evaluated olfactively and the odors qualitatively and quantitatively characterized with three analytical techniques. Sulfur compounds including H2S, methyl mercaptan, and dimethyl-mono-(di;tri) sulfide are important in sewage-like odors of pit latrines under anaerobic conditions. Under aerobic conditions, in Nairobi for example, paracresol and indole reached concentrations of 89 and 65 µg/g, respectively, which, along with short chain fatty acids such as butyric acid (13 mg/g) explained the strong rancid, manure and farm yard odor. This work represents the first qualitative and quantitative study of volatile compounds sampled from seven pit latrines in a variety of geographic, technical, and economic contexts in addition to three single stools from India and a pit latrine model system.

Four windows on modern science in flavor and fragrance chemistry at Firmenich.

Four young scientists, recently hired by Firmenich, presented lectures at the University of Geneva. The objective was to stimulate young students to choose sciences. The challenges in the discovery, synthesis, or extraction of new molecules were presented, as well as the structure-activity relationships of human odorant receptors.

Structure elucidation of a pungent compound in black cardamom: Amomum tsao-ko Crevost et Lemarié (Zingiberaceae).

Natural plant extracts containing taste modifier compounds will gain more commercial interest in the future. Black cardamom, Amomum tsao-ko Crevost et Lemarié, used as a spice in Asia, produces a nice refreshing effect in the mouth. Therefore, an ethyl acetate extract was prepared, and constituents were separated by liquid chromatography. Guided by the tasting of each fraction (LC tasting), a new pungent compound was discovered, (+/-)-trans-2,3,3a,7a-tetrahydro-1H-indene-4-carbaldehyde. To confirm this new structure, a synthesis was performed starting from cyclopentene-1-carbaldehyde. The Wittig conditions were determined to control the stereochemistry of the ring fusion to prepare (+/-)-trans-(2,3,3a,7a-tetrahydro-1 H-inden-4-yl) methanol and (+/-)-cis-(2,3,3a,7a-tetrahydro-1H-inden-4-yl) methanol. After oxidation, (+/-)-trans-2,3,3a,7a-tetrahydro-1H-indene-4-carbaldehyde and (+/-)-cis-2,3,3a,7a-tetrahydro-1H-indene-4-carbaldehyde were tasted in water and only the trans-2,3,3a,7a-tetrahydro-1H-indene-4-carbaldehyde, present in black cardamom, produced a trigeminal effect in the mouth.