The pulpy leftovers of juicing and crushing, called “pomace,” are finding their way into products as diverse as gluten-free muffins, biodegradable flowerpots and edible food wrappings, thanks to Oregon State Extension researcher Yanyun Zhao and cereal chemist Andrew Ross. Loaded with antioxidants and dietary fiber, pomace also controls bacteria and preserves fats, making it versatile as well as nutritious.

“We now know that pomace can be a sustainable source of material for a wide range of goods,” says Zhao.

Juyun Lim, assistant professor of food science at Oregon State University

Did you ever wonder why so many people are attracted to junk food? Why ice cream, french fries and soda pop so often win out over brown rice and broccoli?

It’s not actually a conspiracy by fast-food companies to bewitch people into eating things that aren’t good for them. Well, not completely. It’s largely due to an evolutionary instinct that was useful when people wondered around in the woods searching for food, 100,000 years ago.

In the distant past, we heavily depended on our senses to make a decision of what to eat and what not to eat. In nature, foods that were sweet were almost always safe to eat and were good for us; they made our hunger go away. Foods that smelled odd or tasted bitter or sour usually meant they were potentially toxic or spoiled — and less safe to eat. That was pretty useful information for a person who lived in a hunting and gathering era and wanted to avoid starving or getting poisoned.

In the modern environment where we buy food in supermarkets or restaurants, those same survival instincts are serving only to make us obese and chronically ill.

We have a routine choice of what to eat and how much to eat, and with depressing consistency, we often choose the wrong ones, the ones that carry lots of macronutrients like carbohydrates, sodium and fats. Because foods that are high in sugars, sodium and fats are readily palatable to us, we eat them too much!

Tomomi Fujimaru, a student at Oregon State University, tastes green vegetable juice while wearing a nose clip in research on the role of blocked retronasal olfaction.

The science of flavor – how we taste and smell it, why we like or don’t like it – is still in its infancy. In a series of recent publications in Chemical Senses, we learned that the “congruency” of the different components of flavor is a key to how we perceive the overall flavor of foods. Flavor components that seem to “go” together, like vanillin and sugar, are perceived as a unified sensation that seems to come from the mouth. And barely detectable vanillin becomes so much stronger when sugar is added to vanilla-flavored drink or custard, making it even more palatable.

Actually, that’s our brain playing a trick on us. Vanillin, the primary component of the vanilla bean, has no sweet taste at all, it’s only a smell. And the pleasant sensation is coming not from your mouth but from the nose, through the passageway between the back of the mouth and the back of the nose.

Then, the final decision about what something tastes like is made in neither the mouth nor nose. It’s in your brain, where sensory signals are processed and “bind” as a unified, harmonious perception, like “vanilla custard.” That data gets relayed back to your mouth where you believe the sensations are coming from.

There’s just a lot we don’t know about exactly how people perceive flavor and how it plays a role in food choice and selection. When we learn more about these processes, it might be possible to more effectively teach our palates to like what is good for us. In other words, to really enjoy eating broccoli just as much as eating an ice cream sundae.

The science of flavor is complicated. Some of the players include taste such as sweet, sour, salty, bitter and savory, which is detected solely on the tongue; smell such as vanilla and basil, which is exclusively detected in the nose; and somesthesis, which includes things like touch (the texture of Crème brûlée), temperature (the warmth of soup), and irritation (the burn of hot peppers). All of these sensations provide data to the brain, and it makes the final call.

If you really think you can “taste” everything in your mouth, take a sip of your favorite drink while pinching your nose, and see what it tastes like. Don’t recognize it? Open your nose, and the familiar taste will reveal itself.

The perception of flavor is partly instinct but also a learned behavior. And because it can be learned, there are probably ways that we can teach it. Hardly anyone really likes the bitter taste of coffee the first time they drink it. Since the caffeine in coffee makes them feel energized, however, they learn to like its flavor.

We may never completely lose our desire for ice cream, and we don’t have to. But science may help us find a way to deal a little better with our foods and our dietary choices.

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Juyun Lim is an assistant professor in the Department of Food Science and Technology at Oregon State University. She’s an expert on human sensory perception of food, and sensory and consumer testing methodology. This article appeared in the Huffington Post on June 12, 2012.

Rachel Miller will head for Poligny, France, this summer to test ice-cream recipes. (Photo: Lee Sherman)

When Rachel Miller was shadowing a pie scientist in her hometown of Spokane, Washington, no one — not her teachers, not her parents, and certainly not she herself — could have predicted that her high school job shadow would lead to possibly the coolest summer internship in the universe: tasting ice cream in France.

OK, so let’s back up a minute. A pie scientist? Really? The year was 2008, and transfats were the newest boogeyman in the food industry. The scientist Miller shadowed at Cyrus O’Leary’s Pies was reformulating recipes, replacing shortening with healthier palm oil. Sugar, too, was on the food industry’s hit list as Americans’ waistlines swelled and their blood sugar spiked. Enter low-sugar pies and yet another reformulation.

Miller admits that her teenage choice of a job shadow had more to do with her sweet tooth than with any carefully thought-out career goal. Nonetheless, a career path began to unfold for this child of a meteorologist dad and a veterinarian mom (who worked with bomb-sniffing dogs during a military tour in Kuwait). After a senior-year visit to Oregon State University, Miller set her sights on the Department of Food Science and Technology. Studying food appealed to her practical nature.

“Food science is so applicable to everyday life,” she says. “It’s not one of those sciences where you have to work in a lab. Your kitchen can be your lab.”

A part-time freshman gig crunching data for OSU cheese researcher Lisbeth Goddik introduced Miller to the chemistry, microbiology and artistry of curds and whey. So a logical spot for her first summer internship was Oregon’s famous Tillamook Cheese Factory, where she chemically analyzed milk samples and inspected incoming ingredients like sugar and salt. The next summer, she worked at the Darigold plant back home in Spokane.

Finally, her professional life looped back to its origins: that sweet tooth. At the end of her senior year at OSU, Miller was accepted as a summer intern at ENILBIO, the National School of Dairy Industry and Biotechnology. Tucked away in the picturesque French town of Poligny, the school resides in one of the world’s finest cheese-making regions. The school also researches ice cream.

Miller’s delighted grin seems to say, “Can you believe it?” as she explains her summer job testing the texture of ice cream made without chemical emulsifiers — compounds like polysorbate 80, monoglycerides and diglycerides — that give ice cream its smoothness, free of gritty ice crystals.

“It’s all about mouth feel,” she says, sounding very much like a vintner after swishing, sipping and spitting a pinot noir. “Consumers want a creamy, pleasant mouthfeel, but they don’t want the substances that create that pleasant texture. It’s a Catch 22.”

In France, she’ll be looking at what happens to ice cream, texturally, without those multisyllabic emulsifiers. It’s all part of an international trend, Miller says. More and more, consumers avoid foods listing unpronounceable additives and unrecognizable terminology on their packages. “There’s a big push to clean up the labels on food products, to limit the number of ingredients and to use only natural ones,” she says.

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For more information about education abroad opportunities for OSU students, contact the International Degree & Education Abroad (IDEA) office at 541-737-3006.

Cellulose Power

Professor Michael Penner in the Department of Food Science and Technology is studying one of the holy grails of the bio-based fuel industry: the economical conversion of woody plant materials into ethanol and other value-added products. In the Pacific Northwest, where woody biomass is an abundant source of potential energy, the search for enzymes that can break down the tough-walled cellulose holds huge promise. Unlike the starches found in agricultural crops like corn, which can be easily converted to sugar and then to liquid fuel, woody materials are, in Penner’s words, “recalcitrant” to conversion — that is, they require extra chemical intervention before they reach the simple-sugar stage. Penner’s lab is working on cost-effective ways to attain this critical “sugar platform.”

Bleaching Agent

Fungi that commonly colonize old tree stumps may benefit the paper industry and the environment. In the Department of Chemical Engineering, Christine Kelly is using white-rot fungi and yeast to create a nontoxic alternative for bleaching paper. She has transferred a gene from the fungi, which produce an enzyme that degrades lignin, into yeast that can be cultivated under industrial conditions.

While the enzyme — manganese peroxidase — has shown promise as a bleaching agent in the laboratory, Kelly and Curtis Lajoie, a research professor in Civil, Construction, and Environmental Engineering, are refining the production process. Their goal is to coax the yeast to create an active, stable and highly concentrated enzyme that can replace currently used chemicals.

Microbe Energy

Turning sewage into voltage is the aim of Assistant Professor Hong Liu’s research in OSU’s Department of Biological and Ecological Engineering. Some bacteria living in wastewater can kick off electrons from pollutants. So Liu is developing microbial fuel cells to capture the energy stored in wastewater, while simultaneously treating the water. She envisions a day when developing nations, such as her native China, will have waste-treatment facilities powered by the very waste they process, making them energy self-sufficient and thus more widely affordable.

Liu is also working with Kaichang Li in Wood Science and Engineering to generate electricity from wood. A mixture of the hundreds of small, organic compounds in hydrolyzed wood, the researchers have recently discovered, can be converted directly into electricity with microbial fuel cells. “Liu and I are seeking funding to build the world’s first integrated, portable, compact system for generating electricity directly from wood,” says Li.

Natural Rubber

OSU agronomist Daryl Ehrensing is part of a private-sector initiative to develop a domestic source of natural rubber. With support from Akron, Ohio-based start-up Delta Plant Technologies, Ehrensing is principal investigator for the Department of Crop and Soil Science breeding program to grow a high-yield variety of the Russian dandelion. The plant, native to Kazakhstan, produces a high-quality latex that can be used in auto and aircraft tires. Other universities working on the project are Ohio State, Washington State and Montana State. In another rubber-related project at OSU, this one funded by a German rubber chemical company, Kaichang Li in Wood Science and Engineering is investigating ways to use cellulose crystals instead of silica and carbon black in tire manufacturing.

Food Coatings

Yanyun Zhao, an associate professor in the Department of Food Science and Technology, is focusing on the freshness, health benefits and market value of foods. She is developing biodegradable and edible films and coatings to prolong the shelf-life of perishable delicacies such as strawberries and other small fruits. Other projects include vacuum impregnation and infusion techniques for value-added fruit and vegetable products.

For Jim Kennedy, it’s all about mouth feel. The sensation of wine on the palate can be silky and smooth or coarse and hard. Wine experts call it texture. And along with color, taste and aroma, a luscious texture can cause some people to plunk down $100 or more on a bottle of Pinot noir or Cabernet.

Kennedy is a wine chemist in the OSU Department of Food Science and Technology, and he is trying to put his finger on what creates great texture in red wine. Armed with such information, he says, winemakers could add substantial value to Oregon’s wine production as well as to the grape crop itself. It was the state’s fourth most valuable fruit crop (behind winter pears, sweet cherries and apples) in 2005, worth about $36.5 million, according to the OSU Extension Service.

“If you think about how you sense red wine, first there’s the visual aspect,” Kennedy says. “Then you smell it. That’s the most complicated part of it. There are hundreds and hundreds of volatiles (aromatic compounds) in wine. Then you taste the wine. You’ve got organic acids and some alcohols. Then you feel the wine as it’s in your mouth. That’s the final sensation. I attribute it to tannins, that astringency, a dryness.”

Tannins — a class of compounds with arms-length names (proanthocyanidins, for example) that can readily react with proteins and other molecules — are the focus of Kennedy’s research. But texture is more complicated than tannins, and Kennedy and his colleagues are still trying to tease out all the factors. “We don’t have standards for texture,” he says. “It is such an elusive little thing to figure out, a tough nut to crack.”

The issue is critical for the wine industry. “Texture is one of the two or three sensory measures of great wine,” says Harry Peterson-Nedry, founder and winemaker at the Chehalem winery in Newberg and a member of the Oregon Wine Board. “The feel on the palate, the weight of the wine in the mouth, is extremely important.” Winemakers want to maximize texture, but they lack techniques that are reliable and effective, he adds.

A chemist with industrial experience in experimental design, Peterson-Nedry has provided wine samples for Kennedy’s texture experiments, and the two men have given joint presentations at the annual Oregon Wine Industry Symposium. “Jim Kennedy is one of the premier tannin chemists in the world,” he says. The wine board, which funds Kennedy’s research (along with the U.S. Department of Agriculture and the American Vineyard Foundation), is impressed with his multifaceted approach, collaborating with other OSU researchers with expertise in yeast, flavor and viticulture.

“We’re lucky to have Jim,” adds Rollin Soles, Soles, co-organizer of the annual symposium and winemaker at the Argyle Winery in Dundee. Kennedy’s research, he says, will create the tools for the industry to promote wine texture through practices in the vineyard and in the winery. And those tools need to be adaptable. “If you live in Oregon, you know how conditions can change from wet and cold one year to hot and dry the next. We have to move with Mother Nature to achieve balance in our wines,” he says.

In order to find the chemical fingerprint of texture, Kennedy and his colleagues are working with Peterson-Nedry, Soles and others in the industry to study growing conditions that influence the vigor of the vines and the chemical composition of the grapes. The location of grape clusters on the vine, says Kennedy, affects exposure to sunlight and tannin concentrations in grape skins. Researchers are monitoring the changing chemical environment inside growing fruit, starting from the time when tannins are first produced.

In the laboratory, they experiment with winemaking techniques and submit the results to chemical analysis and the ultimate judges — human tasters. (Lest this appear to be high living disguised as science, Kennedy says of one recent batch of samples, “They were all pathetic.”) Working with Kennedy is an international team of undergraduate and graduate students and a visiting professor and Ph.D. student from Chile on a Fulbright Scholarship.

They have made progress, publishing reports in agricultural and wine industry journals and offering information to growers at the annual Oregon industry symposium. But what they have is just part of the story. “We understand the skeleton (the tannins),” Kennedy says. “Now we’re going to put the flesh on.”

Kennedy has been studying tannins for more than a decade. During his doctoral research at UC Davis in the mid-1990s, Kennedy was looking for a change in tannins that could be related to winemakers’ perceptions of grape ripeness. “They can go out in the vineyard one day and say they (grapes) are not ripe, and the next day, they are,” says Kennedy. “Well, what’s an unripe tannin versus a ripe tannin? The winemakers would say, ‘we don’t know but we can identify it.’”

Despite developing new techniques for analyzing tannins, Kennedy didn’t answer the question in chemical terms during his work at Davis or during his subsequent fellowship at the University of Adelaide in Australia. Determining ripeness is still more art than science, and it remains a holy grail for scientists.

Kennedy’s passion for wine comes from more than chemistry and a desire to help an industry grow. He makes his own — about a barrel a year — and prefers reds. “I love making wine, and I love red wine, but I definitely leave the science out of it. Just the passion. It keeps me grounded in the laboratory,” he adds.

His first attempt at Pinot noir, Oregon’s signature wine, was less than successful. When he came to Corvallis in 2001, Kennedy bought the grapes, crushed them and fermented the juice. He had high hopes. The best wine he had ever tasted was a Pinot noir with a “velvety texture.” He learned first-hand why this grape has earned a reputation for difficulty. “It was the worst wine I ever made in my life,” he says.

When it comes to texture, some wines “carry” tannins better than others. Pinot noir is known as a “temperamental” grape. Tannin concentrations that work in a Zinfandel or a Cabernet can turn a Pinot noir harsh.

Moreover, the source of tannins makes a difference. Skin tannins tend to be “soft” and “more approachable” than seed tannins, says Kennedy, creating a wine that is ready to be consumed sooner. Thus, a selective emphasis on skin tannins helps winemakers produce a balanced wine that matches a trend in wine consumption. Most buyers tend to drink their wine within 24 hours of purchase.

Historically, Oregon’s wine industry has built a reputation for small, family-run businesses producing high-quality wines, especially Pinot noir. That grape accounts for about half of the state’s 14,000 acres of vineyards, which are concentrated in the north Willamette Valley’s hill country southwest of Portland. However, the industry is expanding at the southern end of the valley, eastward into the Columbia and Walla Walla valleys and into southern Oregon where it tends to be hotter and drier.

Kennedy and his colleagues hope their research will help to guide the industry’s growth. Their studies are maturing just as the texture of Oregon’s wine industry is changing, becoming a more robust reflection of the state.