Spencer symposium, Letters, October 2008

1. I met Ron during my time as a “post-doc” at the USDA back in 1995 through 1997. First of all I hardly met another person who showed such great devotion to his research. He really is an astonishing accumulation of consolidated knowledge in his field. I got to know him as a very helpful person with a good sense of humor as well as great amount of wisdom. Any question whatsoever, he always knows an answer or at least some clues to guide you to the right direction. To work with him has always been a pleasure and inspiring at the same time. I could apply a lot of what I learned from him in my later work at different places. I have had a great time with him and his group both in terms of working/learning as well as personal. I congratulate him on the occasion of winning the 2008 Kenneth A. Spencer Award and wish him all the best for the future. Dr. Gerhard Full Chief Quality Control Drom Fragrances GmbH & Co. KG Oberdiller straße 18 D-82065 Baierbrunn Germany

2. When I was getting into flavor research in the 1980s there was a handful of research institutes and names worldwide that were tied to the rapid progress of this relatively new discipline. In particular, the drastically improved analytical capabilities (capillary gas chromatography combined with high resolution mass spectrometry) led to the discovery of hundreds of new genuine flavor components that made it all of a sudden possible to gain a much better understanding of how Mother Nature composes the flavors of the most important foods. One of the most striking challenges was to distinguish the sensorially impactful ones from the not so important ones. Ron Buttery is one of these early pioneers whose name is placed right next to the ones of Roy Teranishi, Walter Jennings, Werner Grosch, Roland Tressl, Pat Williams, Peter Schreier, and some others. The Western Regional Research Center (WRRC) of the USDA in Albany, CA where Ron was working side by side with Roy Teranishi was one of these centers that I was fortunate to visit for the first time in Spring 1985. I will never forget the moment when Ron showed me and explained his dynamic headspace equipment which he was using to collect volatiles from different foods. He had already isolated and identified 2-acetyl-1-pyrroline as the impact component of basmati rice a couple of years before, undoubtedly one of the most impactful flavor components in a food. I also remember his work on bis(2-methyl-3-furyl) disulfide which he identified as an impurity hidden under a much larger peak being the key component of the odor of thermally degraded thiamin and having one of the lowest odor thresholds ever published (0.00004 ppb). Ron never really liked to say too much but one could always sense the passion for his work and for the people around him. I always enjoyed reading his very thoroughly written publications in Journal of Agricultural and Food Chemistry and other journals. I would like to sincerely congratulate Ron for receiving the 2008 Kenneth A. Spencer Award. It is very well deserved. I will always be thankful to him and others for instilling in me the passion for flavor research and giving me reassurance that my career was going in the right direction. Cheers, Ron! Best Regards/Mit besten Gruessen, Dr. Matthias Guentert President Matthias Flavor & Nutrition Division NA __________________________ Symrise Inc.

3. I have had little personal interaction with Ron, but I like many others have been strongly influenced by his published work. Many years ago one of my ex-P&G colleagues, Mike Sevenants, consulted with Ron on the subject of potato chip flavor. At that time, in the early 70's as I remember, we were all trying to understand the origin of potato chip flavor and how to best reproduce it in Pringles. Much of the work then revolved around the chemistry of pyrazines as you might recall. And, around that time similar work was going on in Albany. In 1969 Ron broke new ground in flavor chemistry with the first isolation, characterization and synthesis of a methoxypyrazine, one of the first and still one of the most potent "character impact' compounds to be discovered in food flavors. Years later I became involved with corn chips and corn chip flavor and Ron's work on 2-acetyl-1-pyrroline, 2-acetyltetrahydropyridine shed a lot of light on the significance of those and related compounds in fried corn products. The WRRC flavor research group is world renown for the originality, thoroughness and relevance of its projects due in large part to the contributions of Ron Buttery. I'm sure if I searched my files I could fill a page with more examples as have others you may have contacted. He is truly deserving of the Kenneth A. Spencer Award. Wish him all the best from me. George Rizzi, Ph.D. Procter & Gamble Company Winton Hill Business Center 6300 Center Hill Road Cincinnati, Ohio 45224.

4. Dr. Buttery has made so many contributions; it is difficult to select highlights. To illustration how Dr. Buttery’s research has benefited an industrial flavor scientist, I’ve categorized these benefits into methodology, flavor generation, and off flavor identification. From a methodology perspective, Dr. Buttery has made simple yet profound contributions. He identified the benefits of using Teflon squeeze bottles for aroma assessment. Use of this technique has minimized changes to aroma profiles during evaluations, which has enabled more consistent training and demonstrations. This is particularly helpful when trying to illustrate how various components contribute to overall aroma perception. Dr. Buttery also provided tools to compare partition ratios. This has been extremely helpful in providing the scientific basis for explaining why more is not always better when adding flavor to a product, or why there is not a linear relationship between the amount of flavor added and perceived flavor intensity. Dr. Buttery’s work on the flavor thresholds of nitrogen heterocyclic compounds in Popcorn/ Crackers/ Tortillas, has demonstrated the importance of positional isomers in regards to flavor intensity. In essence this research establishes key analytical benchmarks. From an industrial perspective, these benchmarks establish targets for optimizing flavor generation, and serve as a guide for selecting key ingredients and process conditions. Mike Michael J. Morello PepsiCo Chicago, QTG R&D

5. In regards to off flavors, Dr. Buttery’s research serves as a basis for root cause assessments, which enable rapid issue resolution and more importantly issue avoidance. His research indicating methyl iso-borneol as the key driver of musty flavor in carrots has enabled QC parameters to be established that assure off-flavors are avoided. His work establishing the extremely low odor threshold of bis-(2-methyl-3-furfuryl) disulfide has indicated products fortified with thiamin will eventually develop off flavors, and that the only practical means to completely eliminate this off flavor is to remove thiamin from the fortification package. These are just a few of the many ways in which Dr. Buttery’s research has been applied from an industrial perspective and hopefully illustrates how his research has lead to a more desirable flavor experiences for everyone. Mike Michael J. Morello PepsiCo Chicago, QTG R&D 617 West Main Street Barrington, IL 60013

6. In 1980, when I was a post-doc at the University of Munich, Germany, I had been asked to take care of a project on bread aroma compounds. But as a newcomer at that time, it was a challenge for me to find the right approach, because many people in aroma chemistry just focused their work on volatile identification without any correlation to human perception. However, finally, I found a study on hop aroma compounds by Ron (from 1966), who was among the few researchers proposing the new concept of odor units or aroma values. His basic idea was that only food constituents being present above their odor thresholds are key players in food aromas. I was really fascinated by this approach, and successfully applied this approach in my own post-doc study on bread aroma. Further, with the help of Ron' s data on 2-acetyl-1-pyrroline in Basmati rice, I was able to identify this unstable trace odorant also in wheat bread crust. I have always admired the thoughtful approach behind all of Ron' publications, and it is for sure that he is among the few people who strongly influenced my own research. Univ. Prof. Dr. Peter Schieberle Chair for Food Chemistry/Faculty of Chemistry/ Technical University of Munich and Director, German Research Center for Food Chemistry

7. Today, after 28 years of own research in the area of food aroma chemistry, we call this approach "molecular sensory science", and it is without doubt that Ron is one of the fathers of this idea, which meanwhile has shown many successful application in plant breeding, food processing and, also, flavor creation. Following Kenneth Spencer's statement that "There is no field of human endeavor so enduringly important to man’s welfare as the field of agricultural and food chemistry. Men of vision in agricultural chemistry have always labored to improve on life’s necessities by providing nourishing foods, ......." I strongly believe that Ron is among such men with visions in agricultural and food chemistry. Univ. Prof. Dr. Peter Schieberle Chair for Food Chemistry/Faculty of Chemistry/ Technical University of Munich and Director, German Research Center for Food Chemistry (a member of the Leibniz Association; WGL) and Hans-Dieter-Belitz-Institute for Cereal Research