Reflections on a Half Century of Flavor Chemistry

Dr. John C. Leffingwell
President, Leffingwell & Associates and Honorary Member SFC

In 1954, the flavor use of coumarin was banned by FDA, television screens were small round and black & white and a fine house could be purchased for less than $17,000. It would be 4 years until congress enacted the Food Additives Amendment of 1958 and both FDA and FEMA began developing the GRAS Lists. The first commercial production of synthetic linalool, geraniol and derivatives had not yet started. Although the exact structure of leaf alcohol was established in 1938, it was not widely available until Bedoukian's process in 1961. Less than 500 volatile components had been found in foodstuffs. In 1955 the first primitive commercial gas chromatograph was introduced and it would be about 15 years later before the full power of capillary GC-MS became practical and another 15 with the use of computerized data bases. Nootkatone, 1-octen-3-ol, Ethyl maltol, Furaneol®, Damascenone and Rose oxide were unknown and the use of pyrazines, thiazoles, the meaty furanthiols as well as Raspberry ketone were yet to be discovered. Gamma-undecalactone was not considered nature identical and the importance of certain delta-lactones to butter flavor was unknown. Only 4 of the 5 basic tastes were generally accepted and theories of olfaction were extremely theoretical. Chirality was rarely considered as important in the synthesis of flavor or fragrance chemicals. The structure, synthesis, flavor & odor, pheromonal and plant growth regulation properties of the Methyl jasmonate enantiomers and the dihydro derivatives [Hedione®] (and many others) were yet to be elucidated. Much has occurred in the last 50 years. This talk will review many of the important accomplishments.

Historical Use of Natural Aromas

Robert S. DeSimone, Ph.D., MBA
CEO, Advanced Biotech

Nature has been a primary model for both how we develop flavors and the manner in which flavor chemistry has evolved. Progress in flavor aromatics science has its origins with early essential oil dealers and the Dutch Spice Houses. We will discuss this evolution, beginning with essential oils and extracts, through purified isolates, and ultimately to the wide array of modern synthetic flavor and fragrance aromatics, which are predominantly based on what has been found in natural aroma systems such as foods and floral extracts. We will review how the technical effort in synthetic aromatics surged after WWII concurrent with increased consumer demand, shortages of natural sources, and the development of the petrochemical and pine oil aromatics industries. This evolution of flavor and fragrance aromatics has come full circle in recent years with the expanded availability of Natural Aroma Chemicals.

The effects of sub-threshold compounds in liquid compound flavors and dry blend savory flavors

Richard F. Heinze
Flavor Knowledge Systems, Inc.

Over the years, flavorists have observed formulations containing ingredients below their sensory threshold values. Ingredients in this range are trial and error additions. Sub-threshold additions can contribute to an improved flavor profile, but also can be useless, and add significant cost to a formulation. Cost does not only include raw material costs.

Flavorists add sub threshold ingredients under the umbrella of "creativity", but that because we think these ingredients are all important in improving the flavor profile.
This presentation will attempt to show positive and negative effects of adding sub threshold compounds in flavors.

Food Flavorings - Quest for an "Open Global Positive" List

Ken Schrankel, Ph.D.
VP, Regulatory Policy and Industry Issues, International Flavors and Fragrances

This presentation will describe and provide an update on the various activities around the world that will eventually result in making the "open global positive" list a reality. This will include an overview of the safety program established by the International Organization of the Flavor Industry (IOFI).

The IOFI mission and supporting strategies will be mentioned along with IOFI's recent activities in Asia Pacific, e.g. Japan, Indonesia, China and India.

The History of the U.S. Flavor Industry (1785 - )

John Cassens
President, Cassens Consulting
Executive Director, Flavor Heritage Society

The U. S. Flavor Industry had its roots in Europe in the 18th century. New York City was the birthplace for the Flavor Industry, as early as 1795. Many of today's flavor companies started in the period 1830-1910.

By 1927, almost all flavor companies were centered within five blocks in lower Manhattan, near the East River (South Seaport). There were 72 flavor companies in 1927 in Manhattan. By 1977 there were 17 companies (per Rogers, Dorland). In 2004 only four companies that had the same name as in 1927 remain. The flavor industry first moved "uptown" in New York and then to New Jersey.

The speaker will not only trace company histories but will place special emphasis on the people who have contributed to the success and the rich heritage of the U.S. Flavor Industry.

Communication: Customer Service Along the Flavor Chain

Maria Wallack
Consultant, Wallack's Flavors

The Objective is to integrate the knowledge of Flavor Ingredient Suppliers, Flavorists, and Food Scientists. As a result of this integration, the development of more successful products will be expedited. By reviewing the ways in which we communicate today, including customer visits and the Internet, we can enhance what is most useful for everyone involved. We will discuss the technical knowledge a Flavor Ingredient Supplier can provide that creates superior flavors, as well as the services a flavor company can provide the food manufacturer in order to develop a superior finished product. One challenge is communicating flavor descriptors in a global marketplace.

Vanilla: Past, Present and Crystal-Ball

Michael Fasano
Director of Vanilla Technology, David Michael & Co.

Vanilla has been on a roller coaster since Cyclone Hudah struck the Madagascar growing region in April 2000, destroying not only cured beans ready for shipment but rootstock as well. We will look at the history of Vanilla, including the harvest and curing of beans, some of the effects of Hudah, where things appear to be at the moment and play the speculation game for the future. We will also look at and taste the extracts of beans from some of the different growing regions.

The Perception of Flavor Chemicals

Terry E. Acree, Ph.D.
New York State Agricultural Experiment Station, Cornell University

For 200 years, chemists and especially flavor chemists have believed that once we identified all the chemicals that contribute to flavor in food we would understand how it worked, measure it chemically and predict its behavior. Surprisingly, now that we know most of the flavorants in foods we still do not know how it works.

During the last 7 years, while assembling a database of all the published odorants detectable by GCO that have been reported in foods and beverages, two facts have emerged. The first is that the total number of odorants in the natural world is probably less than 1000 and second that food perceptions are a result of combinations of only a few tens of these odorants. This talk will discuss the advances in the sciences of psychophysics, neurobiology, and genetics that are starting to shed some light on the processes involved in the perception of flavor.

A Savory History Story
or
What did Napoleon have to do with Flavor?

Charles H. Manley, Ph.D.
Vice President, Science and Technology, Takasago International Corp. (USA)

The history of flavor development and creation had its beginnings with the use of natural extracts and synthetic aromatic chemical produced to match the flavor notes of those found in nature. Although many natural materials have very low amounts of volatile components that give rise to their impact they are readily available and can be isolated at useful levels. With the advent of the science of chemistry and, in particular, the discipline of organic and analytical chemistry, any of the “secrets” of the natural extract were discovered and duplicated.

As we all know many of the foods we enjoy are based on cooking or heat processing by various methods. Cooked meats, for example, have always been a craving for humans, yet one that has been is short supply during many times in history. Some 150 years ago a meat flavor substitute was created and since that time man has continue to improve on cooked foods by the creations of more sophisticated savory flavors.

The ‘process flavor’ of today has a long history of use and is one of the most complicated and science based flavor systems that the flavor industry makes today.  The term ‘thermal process flavors’ was coined by the industry to categorize flavors that are generated by cooking or heating processes. Flavors that include meat, coffee, and cocoa and even roasted nuts are in this category and their history and that of the science of ‘process flavors’ is the savory history that this talk will explore.

An Essential Oil Peddler's View of the Flavor Industry -
Past, Present and Future

Richard C. Pisano, Sr.
Citrus & Allied Essences, Ltd.

This presentation will be a lighthearted review of the industry over the last 45 years, recalling interesting and some amusing incidences.  I will also discuss the current challenges facing our industry and future problems which the industry could be facing.

Structure-Odor Relations: A Modern Perspective

Luca Turín, Ph.D.
CTO, Flexitral, Inc.

A novel theory of primary olfactory reception is described. It proposes that olfactory receptors respond not to the shape of the molecules but to their vibrations. It differs from previous vibrational theories (Dyson, Wright) in providing a detailed and plausible mechanism for biological transduction of molecular vibrations: inelastic electron tunnelling. Elements of the tunnelling spectroscope are identified in putative olfactory receptor and their associated G-protein. Means of calculating electon tunnelling spectra of odorant molecules are described. Several examples are given of correlations between tunnelling spectrum and odour in structurally unrelated molecules. As predicted, molecules of very similar shape but differing in vibrations smell different. The most striking instance is that of pure acetophenone and its fully deuterated analogue acetophenone-d8, which smell different despite being identical in structure. This fact cannot, it seems, be explained by structure-based theories of odour. The evidence presented here suggests instead that olfaction, like colour vision and hearing, is a spectral sense.

A perennial difficulty of structure-odor relations has been that both structure and odor have proved hard to pin down. Considered as a structure-activity problem, olfaction is several orders of magnitude more complicated than its conventional pharmacological counterparts because there are many more structures and a vast number of odors. There is also an additional problem: as a sensation, olfaction does not seem to enjoy the same status as, say, vision. Most biologists, indeed most people not directly involved with fragrances or flavors seem to think that odor sensation is “subjective” and not necessarily shared by others. It is striking how few experiments in which odorants are applied to biological preparations take into account the perceived odor of the molecules. We hope that biologists will realize that, once a vocabulary is agreed upon, odor is as reliable a sensation as pitch or color.

The Evolution of Flavor Encapsulation

Gary A. Reineccius, Ph.D.
Professor, Dept. Food Science and Nutrition, University of Minnesota

It is rare that an invention introduces a totally new concept to a field unless is through serendipity. Typically, advancements are made sequentially, one development building upon another until a particular science, or technique, is mature. In terms of flavor encapsulation, serendipity played a role in bringing spray drying to the industry. The accidental discovery that acetone, added to tomato puree to help maintain color and flavor of tomato powder, was retained well in the spray drying process started the development of encapsulated flavorings. Since Neil Revie (A. Boake Roberts and Co.) made this discovery in 1937, the technique of spray drying has advanced greatly through understanding the mechanisms of retention and thereby improving the process.

Encapsulation is typically carried out in commercial practice using one of a number of processes, including: spray-drying (as mentioned), spray-cooling/chilling, freeze-drying, fluidized-bed coating, extrusion, coacervation, co-crystallization and molecular inclusion. Of these processes, all but molecular inclusion are macro processes; processes that typically result in particles having diameters in the range 3-800 µm. In some cases the particles comprise droplets of flavoring material dispersed in a continuous matrix of carrier material, whereas in other cases, the core is continuous and surrounded by a shell of carrier. In contrast, the process of molecular inclusion occurs at the molecular level, whereby individual molecules of food or flavor ingredient are trapped or included within cavities present in individual molecules of carrier (most commonly a cyclodextrin).

In my lecture, I will present an overview of the development of these encapsulation processes and discuss how they have arrived at their current status.

Biotechnology Generation of Flavors and Fragrances

Daphna Havkin-Frenkel, Ph.D.
Vice-President of R&D, Bakto Flavors LLC

Plants make hundred of thousands of natural products, many of which are of huge importance in the flavor and fragrance industries. However, many of these important products are only produced in small amounts, and may come from rare plants grown in remote geographical regions with low accessibility. Recent advances in molecular biology and biochemistry make possible to reproduce nature's chemical range in vitro, in model plant systems, or microorganisms. The production of flavors and fragrances by bioconversion or de novo synthesis with isolated enzymes, plant cells or microorganisms transformed with plant genes will be discussed. These approaches create opportunities for the biotechnological production of a host of compounds. Biotechnologically produced flavors and fragrances bear the label of 'natural', overcome the problem of chirality encountered by chemical production or plant original synthesis. The new approaches afford an industrial scale and/or optimizing agronomic production of natural compounds. This concept will be illustrated by examples from known and yet to be explored plant natural product such as vanillin, benzaldehyde, methyl anthranilate or linanool.

Detection of Physical and Chemical Changes in Flavors

Frank L. Vollaro
Comax Vollaro

Physical and chemical changes occur in flavor compounds, when certain aroma chemicals and certain diluents, are present. These chemicals react and form other compounds that change the flavor, over time. We can measure these changes with gas chromatography and/or mass spectrometry, and we can verify these changes organoleptically. A number of examples will be presented to show how flavor compounds change over time, and how we can predict these changes. Suggestions will be made on how we can prevent certain reactions that are detrimental in flavors.

50 Years of Flavor Analytical Research

Thomas Parliment, Ph.D.
Parliment Consulting

Over the period of years from 1950 to 2000 the field of flavor analytical chemistry made a quantum leap in progress.  Prior to the advent of gas chromatography (GC) and gas  chromatography-mass spectrometry (GC/MS),  flavor isolations and identifications were accomplished by large scale sample workups.  The samples were analyzed by classical chemical isolation, purification and identification techniques. For these reasons, flavor knowledge progress was slow.  During the last half of the 20th century newer techniques permitted the more rapid and efficient isolation and identification of flavor compounds.  In addition, the focus gradually changed from one of identifying lists of compounds to that of identifying specific flavor compounds. In this regard, interest developed in determining the identity of critical flavor compounds. Additionally, we saw the advent of directed reaction chemistry to generate desired specific compounds and the use of biogeneration techniques to produce target compounds.  To support these efforts micro analytical chemistry developed to permit rapid and sensitive component identifications.

The purpose will review the analytical accomplishments of the last 50 years and give an appreciation of the advances that have occurred.  Particular emphasis will be placed on selected analytical isolation techniques which still retain value today and to sensory techniques which reveal critical flavor compounds.

The Flavor Chemistry of Culinary Techniques

Dolf De Rovira
Flavor Dynamics, Inc.

Hinnerk von Bargen, C.H.E.
Assistant Professor in Culinary Arts, The Culinary Institute of America

The standard and acceptable techniques use by Culinarians worldwide have been developed over many years of trial and error and passed down from expert to expert chef through a practical training and tutelage quite similar to that of the flavor chemist. 

The techniques used by the Culinarians have been developed to produce the most tantalizing flavors and the most acceptable results. Upon examination, each of these techniques is well founded in flavor chemistry and represents the optimization of the most complex flavor reactions, lending it to the most interesting and well-rounded flavor results.

We will explore each of the techniques and compare the flavors developed, why the culinary rules and techniques work and how by chemical analysis, and aroma profiling, these techniques have achieve their most favorable results.

1-     The Flavor Chemistry of Sauce Development
         a.      The Flavor Chemistry of The Roux
         b.      The Flavor Chemistry of Bone Extraction
         c.      The Flavor Chemistry of Pincage
         d.      The Flavor Chemistry of Emulsion Sauce Methods

2-     The Flavor Chemistry of Cooking Methods
         a.      The Flavor Chemistry of The Sauteé
         b.      The Flavor Chemistry of The Braise
         c.      The Flavor Chemistry of Frying
         d.      The Flavor Chemistry of Roasting
         e.      The Flavor Chemistry of The Grill

3-     Special Cooking Considerations
         a.      Marinades and Rubs
         b.      Spice Usage
                   i.      Toasting Spices
                   ii.      Smoking with Spices
                   iii.      Cutting, Grinding, etc.

4-     Conclusion
5-     Questions