The making of a meal: Take a bite out of research that improves America’s favorite meal
By Stephanie Jacques
The perfect savory, salty and sweet traditional American meal of a hamburger, fries and ice cream starts far before the raw ingredients arrive in the kitchen.
Kansas State University researchers know the secret ingredients: the bun’s ability to withstand juiciness, the patty’s safe delivery of rich nutrients and the vegetable toppings’ important nutritional qualities. Scientists are keeping all of this in mind as they serve up improvements to the global food systems supply chain.
Making a perfect hamburger bun starts with breeding the ideal wheat plant and extends to every step along the wheat supply chain — from wheat farmers to millers and bakers.
Every year, Allan Fritz, professor of agronomy and a wheat breeder, works to develop and evaluate numerous wheat varieties for their profitability, yield and quality. After pairing parental varieties in the greenhouse, Fritz ends up with about 3,000 to 5,000 new wheat lines within the first five years of an 11-year process. He tests those varieties for the next several years in about 20,000 plots statewide.
“Most of the 5,000 different lines are destined for the trash can, but we should still be able to find one or two really good ones out of that,” Fritz said.
With constant environmental changes, Fritz has to consider multiple factors, such as a plant’s ability to withstand diseases, drought and heat.
“Every year is so different in Kansas,” Fritz said. “We have to identify varieties that can grow in a wide range of environments — not just from location to location, but year to year. That’s a challenge.”
While Fritz is trying to develop the ideal wheat variety, Romulo Lollato, assistant professor of agronomy, is working with farmers to understand how management of nitrogen and sulfur in the wheat field can produce profitable, high-protein wheat.
“Nitrogen contributes to wheat’s protein, which gives the bread better stability, more dough strength and more volume,” Lollato said. “Sulfur, if deficient, can limit yields and the volume of the bread.”
Nitrogen fertilizer is one of the most expensive aspects of wheat production. Farmers don’t want to use any more than needed, but if they don’t deliver wheat with a certain amount of protein, they may see price reductions at the grain elevator, Lollato said.
“We want the wheat to have about 12 percent protein to maintain the baking quality,” Lollato said. “If protein is much below 11.5 percent, then the farmer did not have enough nitrogen to maximize yield.”
Both Lollato and Fritz have worked with Becky Miller-Regan, assistant professor of bakery science and former director of the university’s Wheat Quality Laboratory, to examine wheat varieties for their bread-making quality.
Miller-Regan uses a K-State-developed dough mixing test called the mixograph, which determines the strength of the flour and how much mixing time is needed. The lab also relies on baking tests to better understand the end product’s quality.
“If you are going to see if a wheat variety is good for making bread, then the best test is to actually make bread with it,” Miller-Regan said. “We bake bread and judge the bread based on its size, crumb structure and elastic balance. For example, a hamburger bun needs to have enough strength to hold its shape but flow out a little bit to fill the shape of the pan.”
According to Miller-Regan, bread’s end quality is determined 30 percent by the variety of wheat and 70 percent by environmental factors such as fertilizer, rain and temperature. This makes evaluating the data from Fritz and Lollato extremely important in determining if a variety of wheat will be better suited for a scone, pizza crust or a hamburger bun.
A juicy hamburger patty is the product of one of the world’s best conversion systems. Grasslands have great ecological and economical importance, and while they are a vast resource that is largely indigestible to humans, they can be converted to high-quality nutrients such as zinc, iron and protein for people.
KC Olson, professor of animal sciences and industry, is ensuring cattle’s nutrient conversion of grassland by controlling the growth of sericea lespedeza, an invasive plant species. Sericea has a bitter taste to cattle, and it robs them of natural dietary proteins the animal needs to maintain health, Olson said.
“Cattle, the predominate herbivore in Kansas grasslands, pretty much leave sericea alone because it has tannins that are astringent like lemons or radishes,” Olson said. “Tannins, once they’re in the rumen, bind dietary proteins and render them unavailable for fermentative digestion.”
About 80 percent of cattle’s lifetime calories comes from forages like those in Kansas grasslands, Olson said.
Unfortunately, the progressive invasiveness of sericea displaces nutritious, native plant life for cattle and decreases economic returns for ranchers.
Olson’s research has shown that changing the timing of grassland burning, traditionally done in the spring, can help control the spread of sericea by introducing fire in the summer right before it goes to seed. After spring burns, Olson saw sericea grow from less than 2 percent of a field’s plant population to 11 percent, whereas summer burns helped sericea remain at less than 2 percent. This research gives beef producers a better understanding of how to control a potentially damaging plant.
In addition to managing grasslands, ranchers have been breeding cattle with desired traits for centuries to improve their herds. Megan Rolf, assistant professor of animal sciences and industry, helps ranchers look beyond physical appearances.
“Beef producers have had the ability to use genetic selection tools for several decades in the form of expected progeny differences, or EPDs,” Rolf said. “They now have the ability to use genomic testing as part of those tools to select for traits that are economically and environmentally important.”
Rolf is using RNA, DNA’s messenger in biological roles, in kidney tissue to understand why some animals need less water than others. Her research can help ranchers look at the genetic information of a cow and a bull and decide if their offspring could be more environmentally friendly.
“We want to quantify how much variation there is in both feed and water intake so we can select for more efficient animals, while simultaneously not giving up productivity in other traits that are important for producers and consumers,” Rolf said. “It will help us use land and water resources effectively, which will decrease the footprint of beef production.”
K-State researchers also are looking out for the beef consumer. Randy Phebus, professor of animal sciences and industry and interim director of the university’s Food Science Institute, is part of a $25 million multi-institutional U.S. Department of Agriculture grant to address beef safety.
“We are looking at the prevalence of public health pathogens, particularly Shiga toxigenic Escherichia coli, or STEC, in cattle on the farm and how they find their way into fresh raw beef,” Phebus said. “This group of pathogens produces a toxin that can cause a devastating illness in people.”
According to Phebus, a few hundred STEC cousins can be present naturally in cattle’s intestinal tracts without harm to them. Beef processing can spread contaminants into meat products, and when consumed by humans, the pathogen releases a deadly toxin in the gut.
Phebus helps meat and poultry companies validate their safety processes to control pathogens like STEC and salmonella. Learn more about food safety research from Phebus.
“At the university’s Biosecurity Research Institute, we test multiple antimicrobial applications and processes at a commercial scale using high levels of real pathogens to reduce public health risks in the food chain,” Phebus said
Although food safety is of the upmost importance, a hamburger patty would not be near as popular if it was not satisfying. Travis O’Quinn, assistant professor of animal sciences and industry, is making sure a good old fashioned hamburger still tastes delicious as people become more health conscience.
According to O’Quinn, a burger’s juiciness is tied to its fat content, which is perceived to improve taste. O’Quinn did a blind survey where participants tasted various blends of lean versus fat in hamburger, such as 70 percent lean/30 percent fat, 80 percent lean/20 percent fat and 90 percent lean/10 percent fat. Participants rated each patty on tenderness, juiciness and flavor. In a second test, each patty was labeled by the quality of the cuts of meat ground into the hamburger: ground round, ground chuck or ground sirloin.
“What was really fascinating is all of the differences once we told consumers what it was,” O’Quinn said. “We got a huge change in their rating from the blind to the informed testing, especially with the labels of sirloin and 90/10 fat content.”
O’Quinn said that the 90/10 ground sirloin wasn’t one of the high-performing patties in the blind tasting, but its rating improved 14 percent in the labeled testing.
“This was the first study that really demonstrated that consumer perception has as big of an impact as what is in the meat,” O’Quinn said. “All that branding makes a difference.”
Kelly Gude, doctoral student in horticulture at the K-State Research and Extension Center in Olathe, is shining a light on yield and nutritional quality of tomatoes and leaf lettuce grown in high tunnels. According to Gude, high tunnels — structures similar to greenhouses that allow farmers to manipulate light over produce — have improved crop productivity with fruiting vegetables and leafy crops, but they may come at a cost.
“There are sporadic reports of inconsistent and negative impacts on nutritional quality of produce grown in high tunnels compared to an open field,” Gude said. “In particular,
ultraviolet light can affect antioxidant capacity and other phytochemical production of the plant.”
Gude is testing basic slicing tomatoes, “BHN-589,” and two lettuce varieties, “Red Fire” and “Two Star.” She is measuring nutrients such as beta-carotene, lycopene and lutein, which are precursors to vitamin A and are cancer-fighting antioxidants also important for human eye health.
Gude is evaluating how different high tunnel coverings filter light and temperature and how they affect crop yield, storage life and nutritional quality of tomatoes and lettuce. The research could help producers maintain good yields and vegetable nutrition.
Sweet potato fries are growing in popularity, but producing the seed that can support the nutritious orange spud proves to be more difficult in the Midwest. Zachary Hoppenstedt, master’s student in horticulture at the K-State Research and Extension Center in Olathe, is digging around ways to get slips — stem cuttings used for sweet potato reproduction — to local producers.
“In the U.S., commercial sweet potato production and propagation is largely concentrated in southern and coastal states and a Midwest supply of organic sweet potato slips can be limited,” Hoppenstedt said.
As the demand for locally sourced produce increases, Hoppenstedt is improving wholesale production methods for organic sweet potato slips in the region. His trial evaluates the use of greenhouse-like high tunnels as ways to give producers in colder climates greater flexibility for planting and harvest.
“Increasing the capacity for local growers to produce their own planting material is one way to support sustainable community and economic development,” Hoppenstedt said.
The secret behind ice cream as delicious as the ice cream made at K-State’s Call Hall Dairy Bar comes down to chemistry. According to Karen Schmidt, professor of animal sciences and industry, a good ice cream, at its basic level, has a blend of ice crystals, air bubbles, protein, fat and sugar. All of those properties combine to give ice cream a fluffy texture.
“Heating the cream, milk and sugar helps the proteins bind water, which adds a foaming texture that prevents it from freezing solid like hamburger,” Schmidt said. “Also, the faster you freeze the mix, the smaller the ice crystals will be, which results in a smoother and creamier ice cream.”
Schmidt is studying heat treatments to kill microorganisms in nonfat dry milk, which increases foaming and gelling textures in commercial foods, ranging from ice cream to hamburger buns, for greater firmness and cohesion.
Textures aside, a great ice cream also needs to tantalize the taste buds. The most notable ice cream flavor made at K-State’s Call Hall Dairy Bar is Purple Pride, which is made with blueberries. The fruit is just one of the many kinds of produce that could benefit from bio-based food packaging research at K-State.
Valentina Trinetta and Umut Yucel, both assistant professors of animal sciences and industry in the university’s Food Science Institute, are developing a special food packaging film that would guard against foodborne pathogens and microorganisms to extend the shelf life of berries.
“We have put together an active packaging system for food that has active ingredients that are released over time,” Trinetta said. “The packaging makes the food safer and last longer because it has active antimicrobial properties encased in nano-emulsions that act against foodborne pathogens.”
The researchers tested the film on strawberries and observed a 20 to 30 percent reduction in microbes, a two-day longer shelf life and improved color retention. A patent is approved for the packaging and consumers should see longer shelf lives for berries in the near future.