Glenn Roy began training in the science of flavors and fragrances in 1971 with Tombarel Freres in Grasse, France. As a field laborer from before sunrise to 12 noon, he harvested botanic raw materials and processed them to produce essential oils and absolutes. Perfumery studies continued as part-time employment with Givaudan Corp. and Roure, Bertrand, Dupont, Inc. both in NJ. In 1975 he was graduated with a B.A. in chemistry from St. Michael’s College in Winooski, VT. There Mr. Roy researched and published with the late Dr. Gilbert Grady a new method for the purification of eucalyptol 1,8-cineole from its olfactorally undesirable 1,4-isomer. Subsequently, he was graduated with a M.S. (1977) and Ph.D. (1980) degree in Organic Chemistry from study and research at The Ohio State University, Columbus OH under Dr. Philip D. Magnus, Royal Chemistry Society Fellow. A discovery of new organosilicon reagent methodology was illustrated in the syntheses of Frontalin, a beetle pheromone and Latia Lucifern, a firefly luminescence principle. The organosilicon reagents are now commercially available from Petrarch Co.. In 1980 Dr. Roy entered a career in the food industry. Six years of research were conducted in flavor generation, high potency sweeteners and taste modifiers at (then) General Foods Corp. (Tarrytown, NY). Over 20 US patents were granted for new sweeteners. In 1986 a wonderful opportunity arose to pursue research at The NutraSweet Co. (Mt. Prospect, IL) in the area of non-fermentable, non-caloric sugar and fat macronutrient substitutes. Additional research in taste modification resulted in the discovery and patenting of bitterness inhibitors. In 1989, Dr. Roy returned to France as a guest speaker on taste and taste modifiers. However, the impending break-up of The NutraSweet Co. R&D with the expiration of the Aspartame sweetener patent prompted a 1990 move to a managerial position in Food Processing Technical Services with Calgon Carbon Corp. in Pittsburgh, PA.
Dr. Roy published the first book on the use of Activated Carbon in Food Processing and Pharmaceutical Applications with Technomic Publishing Co. in Lancaster, PA. He also received a US patent for a continuous food-frying oil treatment to reduce color and polymer formation. The process was not commercialized as regulations for oil contaminants emerged. Used frying oil is now burned as fuel oil. In November 1994, the corporate downsizing of Calgon Carbon Corp. resulted in unemployment (again). In March 1995, Glenn Roy joined The Pepsi-Cola Company (Valhalla, NY) as a Principal Research Scientist in Ingredient & Flavor Technology of Nutritional and Botanical Beverages. In April 1997, Modifying Bitterness: Mechanism, Ingredients, Applications was published. This was the first book of its kind. Dr. Roy has now compiled a book on in vitro Taste Sensors (The Electronic Tongue). In February 1999, Dr. Roy was appointed as a Research Fellow at PepsiCo as a result of taste modifier work to develop Pepsi ONE. Most recently he has discovered natural ingredients to prevent UV-induced color fading of beverages, a tea browning inhibitor to replace ascorbic acid, and bubble modifying ingredients for soft drinks, all enabling the commercialization of new PepsiCo beverage products. In 2011, Dr. Roy designed a fractionation laboratory and led a team of 4 analytical chemists in the fractionation of botanical extracts for new sweeteners in the $1.6MM lab. A Corporate career model change was an incentive for my early retirement.
Dr. Roy’s interests also include: competing in British Sport Car Shows and Races with personally restored British Leyland Triumphs 1964 TR4 (my very first car) and a 1973 Stag V8, vacationing at my log cabin on 67 acres in Granby VT, bow hunting for deer (to fill the deep-freezer), and trout fishing.
In Vitro Taste Sensors: The Technology and Applications
The flavor, aroma, and texture of foods and beverages drive consumer preference and purchase intent. Generally, in product development stages, products are tested in sensory panels to determine which variant of a chosen set are the preferred and the ideal candidate for further consumer testing leading to commercialization. So sensory panels are the industry's standard in product development and they give the indication of what specific attributes are important to the taste, aroma and texture of a product. Sensory tasting panels are fatiguing and require commitment on the part of panelists to attend and be consistent in their evaluation of blinded samples. In the absence of a willing, precise and trained human taste panel, as well as the need for a high through-put screening tool capable of real time assessment of product quality, the need for in vitro taste sensors correlated to human sensory perception is growing. Consistent product quality in production assures the consumer's receipt and consumption of what was intended to be the product desired. In the industrial and academic limelight, this technology is affectionately called an electronic tongue. This presentation will review the literature on the Technology of Electronic Tongue Sensing Devices (Artificial Membranes: lipid/PVC/DOPP, phospholipid LB films; Natural Sensors: Enzyme LB Films; adzuki bean roots; Light Addressing Potentiometers (LAP); Surface Photovoltage; Surface Plasmon Resonance (SPR); QSFET; Water/Oil/Water Liquid Membrane; Agar-Gel Salt Bridge; and Optical Fibers). We will examine the measures and interpretations of device effects on the basic tastes of sweet, salt, sour, bitter and umami. Illustrations will help us discuss the Principal Component Analyses for Sensory Applications of Food and Beverage QC in beer, coffee, carbonated soft drinks, tomato juice, sake (amino acids), milk; soy sauce, red wine, apple wine, consome, vinegars, juices, miso, soybean, mineral water, boiled rice, tea, wort and beer, analgesics, drugs, sweeteners, and sesame oil.
Modifying Bitter Taste
The oral sensation of bitter taste is often unpleasant to the human palate, and therefore, formulations of foods, beverages, and oral pharmaceuticals attempt to alleviate or ameliorate bitter taste perception. The Calorie Control Council (CCC) reported that food research into bitter taste modulation has reached a new level of importance to the flavor industry by using knowledge learned from the pharmaceutical industry and rational flavor design. I published a comprehensive review of the most recent literature, Modifying Bitterness; Mechanism, Ingredients, Applications, in April 1997, and this presentation will highlight the book. The context is ingredient or processing approaches effecting bitter-taste reduction or inhibition. Additionally, a brief biochemistry clinic will provide an understanding of the mechanism by which bitter taste is perceived and its similarity to sweet taste perception. The utility and advances of taste sensors will be briefly reviewed to point out their unique and potential ability to screen for bitter tasting substances and formulations without recruiting a willing human taste panel. Some additional identification of bitter chemical principles and sources of bitter food products are summarized for their relevance speaking to the topic of future end-product palatability. Some discussion will also address bitterness in salt substitutes (KCi) and the taste control of sweeteners with a bitter aftertaste (e.g., Sweet N' Low or saccharin, Sunett or acesulfam-K). The presentation will make recommendations of applications and techniques in oral pharmaceuticals to control bitter taste. Oral pharmaceuticals are the most successful marketplace for the possible use of a specific inhibitor for bitter taste. In closing, the presentation will offer a cautionary and futuristic perspective of what could be done to add another staple to the table, i.e., a bitterness inhibitor to complement a salt and pepper shaker. However, when using bitter taste reduction and inhibition, fair warning to those practicing the molecular design and synthetic chemistry for bitterness inhibition and reduction.
The electronic tongue applied to bitterness inhibition of acesulfame and saccharin
Sensory panels are the beverage industry's assessment standard for taste, aroma and texture in beverage product development. There is an observed human unwillingness to return attendance for bitter-tasting beverage taste panels. Therefore, the need exists for an alternative assessment tool correlated to human sensory perception of bitterness and its reduction. There is also a need for a high throughput screening tool capable of assessing bitterness inhibition when potential taste modifying substances cannot be legally tasted due to untested toxicology or questionable efficacy in bitterness inhibition. The electronic tongue (an in vitro taste sensor) has been utilised to screen numerous chemical classes of literature-reported bitterness inhibitors when added to the bitter after-tasting sweeteners acesulfame (Sunette brand) or saccharin in a low pH carbonated or non-carbonated beverage model. Multivariate Statistics of the beverage model with additives provides Principal Component Analyses and Discriminant Factorial Analyses compared to reference standards of good, better, and best bitter- reduced model beverages. These analyses illustrate the quantitative inhibition effect of the bitter aftertaste. In certain cases where tasting is legally permitted, there is a defined positive sensory correlation to the device's interpretations of bitterness inhibition. We believe we have a high throughput screening assay (assessment tool) for evaluating potential new bitterness inhibitors when employing Soft Independent Modeling of Class Analogy (SIMCA) to quantify specific characteristics of new lead compounds. Appropriate toxicology and regulatory procedures may permit human sensory evaluations to confirm the absolute utility of the device.
Retired, Research Fellow
PepsiCo, Global Long Term R&D