Flavor Analysis Integral to Product Development
LABORATORY
The flavor of a food product is the single most important factor that determines its commercial success, according to Varoujan Yaylana, Associate Professor of Food Chemistry at McGill University (Canada). “Knowledge of the differences in flavor composition between different samples can lead to a better understanding of the differences in their processing conditions and the presence of specially added ingredients that give rise to the perceived differences,” he said.
I spent most of my life practicing that philosophy in food product development, and now I find I was really a practicing food chemist or flavor technologist without knowing it. Food scientists spend a lot of R&D time improving flavors and customer acceptance, but that is always after first assuring themselves of product safety. It doesn’t take a food scientist at the workbench long to realize that if a little bit tasted good, adding a lot more didn’t make it taste better!
In the companies I worked for, we had some flavor control through the process used. But for delicate or sensitive flavors, for the starting level of usage that would please a majority of our customers, or for the reason why a product didn’t sell beyond the first free sample, we turned to our supplier’s flavorist or to our own in-house sensory evaluation panels to guide us. We quickly found that the company vice-president who thought the new product tasted “yummy” was not an expert on flavors throughout our customer base.
Scientists are still studying why the Maillard reaction (or browning reaction) changes the flavor in some foods and the lack of browning in the microwave cooking process causes less acceptance of a flavor in many foods. Considerable progress has been made in achieving freshly baked flavors, meat flavors, or more acceptable colors in microwave cooking, but many more research hours and sometimes expensive equipment are required. Techniques include pyrolysis coupled with gas chromatography/mass spectroscopy, linked-scan mass spectroscopy, high-performance liquid chromatography (HPLC) with a multi-detector system, and Fourier transform infrared spectroscopy (FTIR).
I contacted various flavor experts to discuss flavor perception , sensory analysis, and flavor development. Here’s what they said.
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Flavor Perception
Gary K. Beauchamp, Director of Monell Chemical Senses Center, Philadelphia, Pa. (phone 215-898-6666), stressed the dependence of food qualities on flavor. “The flavor of a food or beverage is dependent upon the taste, odor, and some esthetic characteristics imparted by the ingredients,” he said. “We are investigating basic mechanisms of flavor perception, including how flavor molecules interact with sensory receptors in the oral cavity, how the central nervous system processes this information, and how flavors influence behavior.
“Although a primary question asked in food flavor testing is how much people like a particular flavor,” he added, “it is also important to evaluate qualitative and quantitative issues of flavor perception. Typically, highly trained panels of people are employed to do this, but recently, complementary techniques that use animals and animal and human tissue and receptors have been developed for the first stages of flavor screening.
“For example, we are using olfactory, trigeminal, and taste receptor cells, taken at biopsy from humans or other mammals, to screen for flavor modifiers. These techniques allow one to efficiently screen many compounds for candidates that may have specific flavor effects. Analogous techniques with receptors and receptor cells are being used by biotechnology companies such as Senomyx and Linguagen.”
Another technique used at Monell for certain purposes, particularly in conjunction with pharmaceuticals, involves animal models. “During drug development,” Beauchamp said, “it is unwise or impossible to test humans for their perception of a drug, but it is possible to develop animal, generally mouse, models which can be used as an initial screening tool both to determine taste profiles and to investigate possible modifiers such as inhibitors of bitter or off-tastes.
“For a more global measure of human flavor perception,” he continued, “brain imaging techniques hold great promise but remain mainly experimental at this time. These techniques, such as functional magnetic resonance imaging (fMRI), offer the potential to directly visualize parts of the human brain that are activated by specific flavors. Brain imaging techniques have many problems, technical and financial, but they are likely to provide important tools in future flavor testing. At Monell, scientists are investigating brain areas involved in liking and cravings for flavors using fMRI. In the future, it should be possible to obtain nonverbal measures of liking, preference, and choice using brain imaging,” Beauchamp concluded.
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Sensory Evaluation
Flavor measurement and its related attributes are also often evaluated through the expertise of trained sensory panelists, for both product development and formulation improvement. These sensory panels may be conducted in-house or through outside firms. One such firm is Food Marketing Support Services, Oak Park, Ill. (phone 708-386-7809), a contract R&D company with experts in the sensory evaluation and product research fields that specializes in new product design and optimization.
Nancy Rodriguez, President, said that the company applies a highly creative development approach based on descriptive analysis, a sensory method that combines precise analytical measurement techniques and the abilities of highly trained, articulate panelists with creative application situations.
“Our use of descriptive methodology extends beyond the roundtable into real-world situational experiences,” she said. “We listen, touch, smell, taste, and feel the world’s stimuli, targeting consumer-generated need states. We talk with consumers, assimilate consumer research into the design plan, and travel beyond the laboratory before we begin working at the bench level.”
“Our descriptive abilities have enabled us to create concepts that reach beyond the obvious,” she added. “We design to precise appearance, aroma, flavor, texture, and handfeel targets or models that result primarily from consumer-based key driver analyses. Using descriptive models as guidelines supports robust product design. Ingredient sourcing, manufacturing, and packaging requirements, as well as quality assurance specifications, are targeted during the development process. We benchmark product adjustments during the development process. As the product evolves, descriptive documentation provides cause-and-effect direction, as well as clarity about ‘model fit.’
“Creative, exploratory descriptive models and descriptive benchmarking throughout development minimize risk for clients,” she said. “When the target or model is achieved, predicted consumer liking and purchase intent hurdles will be met.”
Working with Flavor Suppliers
“Taste is always crucial among consumers, and with the latest ingredient and technological innovations, it is the food technologist’s task to design great products with great taste,” said Mariano Gascon, Flavor Laboratory Director, Wixon, Inc., St. Francis, Wis. (phone 414-769-3000).
Ingredients and processing factors such as heat, process time, and even packaging can affect the flavor of the finished product, he said. Therefore, involving a flavor supplier at an early stage in the development process can significantly improve the product quality and make a successful product in the market.
For instance, a food technologist wishing to develop a vanilla pudding that would be sold out of the refrigerated section of the supermarket would start with milk, which provides the liquid and the protein for the system. Then, he would add starch to thicken the formulation, and design a preservation system to guarantee a safe product with a three-month shelf life. At this point, the food technologist would approach a flavor supplier to request a flavor for the product.
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The food technologist might request a vanilla flavor for a pudding and that the sample be delivered within a week. Flavor chemists would work on the product and ship the sample in six days. After an excruciating wait of three weeks, the food technologist might respond that “It’s good, but it needs to be less caramel and more vanilla.” The food technologist knows exactly what that means, but the flavor chemist finds the request difficult to interpret. Depending on the product, this could go back and forth for several more attempts. This represents a huge problem, Gascon said, because customers often expect the flavor chemist to get the flavor right the first time, or within two or three shots.
Once the right flavor is designed, the food technologist makes the product in the lab and approves it. Then he makes a pilot trial that fails. Why? Because many times ingredients and processing conditions affect the flavor of the finished product. Factors such as heat, process time, and even packaging will alter the flavor of the finished product. The food technologist now must go back the drawing board and start all over.
“Having flavor chemists work side by side with the product developer, almost in a partnership,” Gascon said, “could make the traditional product development better and faster, for two reasons: First, the flavor chemist can bypass the expensive and error-prone effort to understand the food technologist’s needs in detail. Second, the trial-and-error cycles that inevitably occur during product development can progress much more quickly because the iterations will be performed in a closer environment of communication.”
Besides the sensory evaluation expertise provided, he added, working closely with the flavor chemist can also bring a multitude of analytical equipment into the picture, such as GM-MS, HDLC, spectrophotometer, etc. “These tools are often used to analyze and develop flavors,” he said, “but they can also be used to identify ingredient interactions or side reactions that are affecting the flavor of the finished product developed by the food technologist.”
Does smelly cheese smell ‘good’ or ‘bad’?
In late November 2004, it was announced to the food industry that the newest “smelliest” soft, yet still firm French cheese is Vieux Boulogne. The artisan-made cheese was tested for its smell along with other known pungent cheeses by researchers at Cranfield University, UK, on behalf of Fine Cheeses from France.
The cheese—which is derived from cow’s milk which is matured by washing with beer—was tested against (and beat) other strong-aroma cheeses like Levered, Brie, and Munster. And if that wasn’t enough insult to the old classics, Pont l’Eveque—another cheese from cow’s milk, washed with a type of brandy—won second place. Camembert de Normandie AOC—which has a natural rind having a mushroomy aroma—came in third.
“Love it or loathe it, the sign of a fine cheese is often its characteristic smell as well as its flavor and texture, and we wanted to find out if France’s reputation for producing smelly cheeses was true,” said Sally Clarke of Fine Cheeses from France.
Stephen White, Senior Research Officer at Cranfield University, used an electronic nose and a human olfactory panel to sniff 15 cheeses selected with the help of cheese experts in France and the UK. “The results suggest that electronic nose technology could be a useful tool for cheese characterization, quality control, and authenticity testing in the future,” White said. More information on the test is available at www.cranfield.ac.uk/university/press/2004/26112004.cfm. More information about French cheeses is available at www.frencheese.co.uk.
by DEAN DUXBURY
Contributing Editor
Consultant, Oak Brook, Ill.
[email protected]