Monday, August 24, 2015

Americans Support Local Food Markets to Feel Part of Something Bigger Than Themselves

Newswise, August 24, 2015 — CHICAGO — More Americans than ever before are supporting their local food markets, and it’s not just because they believe the food is fresher and tastes better.

According to a new University of Iowa (UI) study, people are shopping at farmers markets and joining food co-ops in record numbers because they enjoy knowing who grows their food. These so-called “locavores” are also driven to eat locally grown produce and locally raised meat because their commitment to do so makes them feel a part of something greater than themselves — a community that shares their passion for a healthy lifestyle and a sustainable environment.

For these enthusiasts, supporting the local food movement is a sort of civic duty, an act to preserve their local economy against the threats of globalization and big-box stores.

“It’s not just about the economical exchange; it’s a relational and ideological exchange as well,” said Ion Vasi, an associate professor with a joint appointment in the Department of Sociology and Tippie College of Business at the UI and the lead author of the study.

Vasi said the local food market is what sociologists call a “moralized market,” that is a market in which people combine economic activities with their social values. Among their findings, the UI researchers discovered local food markets were more likely to develop in areas where residents had a strong commitment to civic participation, health, and the environment.

“It’s about valuing the relationship with the farmers and people who produce the food and believing that how they produce the food aligns with your personal values,” said Vasi, who will present the research at the 110th Annual Meeting of the American Sociological Association (ASA).

As part of their study, Vasi and his co-authors examined the development of local food markets by looking at the number of farmers markets, food co-ops, community-supported agriculture providers, and local food restaurants in cities across the United States. The researchers also conducted 40 interviews with consumers and producers in different local food markets in Iowa and New York.

From a historical perspective, the recent growth of local food markets is rather surprising.

In 1971, Jane Pyle predicted farmers markets were “doomed by a changing society” in an article penned for The Geographical Review. At the time, there were about 340 farmers markets left in the United States and many were “populated by resellers, not farmers, and were on the verge of collapse,” Pyle wrote.

However, according to the United States Department of Agriculture (USDA), national direct-to-consumer food sales increased three-fold between 1992 and 2007, growing twice as fast as total agricultural sales. 

The number of farmers markets listed in the USDA National Farmers Markets increased from 3,706 in 2004 to 8,268 in 2014. Plus, Vasi and his co-authors found the number of Internet searches for farmers markets almost tripled during that same 10-year period and the number of newspaper articles that mentioned farmers markets almost quadrupled.

So, what’s behind this need to know who grows your food and to believe in how it’s produced?

It was the onslaught of big-box stores and globalization forces that reignited “buy local” campaigns across the country in the 1990s, said the UI researchers.

“A growing number of communities have attempted to gain control of their own economies by encouraging civic engagement that supports investing in locally owned businesses instead of outside companies,” states the study.

Sara Rynes, a professor of Management & Organizations in the UI’s Tippie College of Business, and co-author of the study, said the researchers also found that local food markets (i.e., farmers markets, food co-ops, etc.) were more likely to be located in cities and counties with higher education levels, higher income levels, and more institutions of higher education.

“Sociologists and political scientists have argued that higher income allows people to make consumption decisions based on values in addition to matters of price,” Rynes said. 

“Education is likely to facilitate knowledge about such things as links between the way products are produced and their environmental and health impacts. And universities sometimes get involved in helping local farmers and individuals who are struggling to make a living.”
###

About the American Sociological Association
The American Sociological Association (www.asanet.org), founded in 1905, is a non-profit membership association dedicated to serving sociologists in their work, advancing sociology as a science and profession, and promoting the contributions to and use of sociology by society.

The paper, “Resurgence of the Locavore: The Growth of Multi-Motive Local Foods Markets in the United States,” will be presented on Saturday, Aug. 22, at 8:30 a.m. CDT in Chicago at the American Sociological Association’s 110th Annual Meeting
.

Wednesday, August 19, 2015

Get a Taste of the Science Behind Taste

Newswise, August 19, 2015 — Whether we’re eating breakfast, lunch, dinner or a bedtime snack, taste is something we experience every day. However, we rarely pause to think about the science behind why something tastes good or bad, or why we may like certain things others don’t. Robin Dando, PhD, Assistant Professor in the Department of Food Science at Cornell University, specifically researches taste and answers the following questions about the science behind taste.
Q: How do people decide whether or not something tastes good?
A: Eating triggers inputs from all five senses, not just from taste. Taste is 
influenced by smell, vision and the sound of the food as we eat it. Additionally, touch receptors in the mouth and tongue tell us how crispy, crunchy, or pleasing the texture is. All of these signals put together inside of the brain make a decision about if we find the food pleasing or not. 
Q: How can one food taste good to one person and bad to another?
A: Each person appreciates foods differently. People have different sensitivities to tastes and to smells and are brought up differently. This means consumers have different experiences when eating foods. For instance, being brought up in a home where spicy foods were commonly eaten would probably mean they would enjoy spicy foods more than someone who was brought up differently.

Q: How does a person’s sense of taste develop or change over time?
A: Children are very sensitive to bitter tastes, which is one of the reasons they don’t like vegetables as much as adults do. Children also enjoy intense levels of sweet, sourness and saltiness that perhaps adults wouldn’t. This matures as people age because they get an appreciation for more complex tastes as opposed to something that’s intensely sweet. As people get older, taste and smell starts to decline, which means they’re not as sensitive to certain tastes.

Q: What physiological factors impact taste?
A: Taste can be affected by things from both the outside world and from within the body. Foods can taste differently if they’re presented on a different dish or with a food dye that doesn’t taste of anything in particular. Those would be considered outside influences. Within the body, there are circulating hormones that have receptors inside of the taste buds. This means that when these particular hormones or high or low, it influences how people taste things.

About IFT
Founded in 1939, the Institute of Food Technologists is committed to advancing the science of food. Our non-profit scientific society—more than 17,000 members from more than 95 countries—brings together food scientists, technologists and related professionals from academia, government and industry. For more information, please visit ift.org.

5 Reasons Why Sugar Is Added to Food

Newswise, August 19, 2015—From a food science and technology perspective, sugar (sucrose) plays several roles when it comes to the functional properties in food. In the September issue of Comprehensive Reviews in Food Science and Food Safety published by the Institute of Food Technologists (IFT), authors from the University of Minnesota write about the functional properties of sugar and why they are often added to foods.

1. Taste: Sweetness improves the palatability of many foods. Adding sugar to foods with high nutrient quality may increase the chance they are consumed. In addition, sugar plays an important role in contributing to the flavor profile of foods by interacting with other ingredients to enhance or lessen certain flavors.
2. Color and Flavor: The Maillard reaction is a chemical reaction between amino acids and reducing sugars that gives browned foods their desirable flavor; and caramelization is fundamental to the formation of color in several food products and can’t happen without the addition of sugar. Caramelization happens when sugar is heated to a certain temperature and is used in a wide variety of products including sauces, candies, breads, jams, and dessert wine (Kroh, 1993). The Maillard reaction also provides desirable flavor formation in foods such as baked goods, chocolate, coffee and meat (Danehy and Wolnak, 1983).
3. Bulk and Texture: Sugar provides bulk to foods which impacts the mouthfeel and texture. Sugar affects multiple chemical reactions that form the texture of baked goods, ice cream, candies, and jams, preserves and jellies.
4. Fermentation: Fermentation is a process in which microorganisms in the absence of oxygen generate energy by oxidizing carbohydrates, like sugar. Sugar aids in the fermentation of many common food and beverage products produced including yogurt, vinegar, sour cream, wine, beer, bread, cheese, soy sauce, and sauerkraut.
5. Preservation: The hygroscopic nature of sugar plays a crucial role in reducing water activity in foods. Hygroscopic is defined as the ability to absorb water from the surrounding environment which helps in preserving and extending the shelf-life of food products (Kitts, 2010). Sugar also prevents baked good from becoming dry or stale (Spillane, 2006) and it also preserves the color of frozen fruits and jellies.
This article in Comprehensive Reviews in Food Science and Food Safety also discusses the challenges of labeling added sugar and the technical issues associated with replacing added sugar in foods.
Read the full article here.

About IFT
Founded in 1939, the Institute of Food Technologists is committed to advancing the science of food. Our non-profit scientific society—more than 17,000 members from more than 95 countries—brings together food scientists, technologists and related professionals from academia, government and industry. For more information, please visit ift.org.


Better-Tasting Grocery Store Tomatoes Could Soon Be on Their Way

BOSTON, Aug. 19, 2015 — Tomato lovers rejoice: Adding or rearranging a few simple steps in commercial processing could dramatically improve the flavor of this popular fruit sold in the grocery store, according to researchers.

The scientists will present new research on flavor-saving methods at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society. The meeting features more than 9,000 reports on new advances in science and other topics. It is being held here through Thursday.

“Ideally, tomatoes should be picked ripe and then sold immediately, as they are at farm stands,” says Jinhe Bai, Ph.D. But this isn’t always possible for commercially sold tomatoes, which are often stored and then shipped over long distances.

To prevent tomatoes from becoming too ripe before they reach the store, growers pick them when they are still green. Packers then use a gas called ethylene to trigger fruit ripening, and after that the tomatoes are stored and shipped at low temperatures.

The problem is that chilling tomatoes degrades their flavor, says Bai. In an effort to improve the flavor quality, his team developed a slightly different method. 

“To produce a better tasting tomato, we added a hot water pre-treatment step to the usual protocol that growers follow,” he explains. “We found that this pre-treatment step prevents flavor loss due to chilling.”

Describing the process in more detail, Bai explains that he and his colleagues at the U.S. Department of Agriculture, Agricultural Research Service, and the University of Florida dipped Florida-grown green tomatoes in hot water (about 125 degrees Fahrenheit) for five minutes and then let them cool at room temperature. 

Next they chilled the fruit to between 41 and 55 degrees Fahrenheit, the temperatures commercial producers use for shipping. After the tomatoes fully ripened, the researchers tested them for flavor and aroma.

They found that tomatoes heated before chilling had higher levels of flavor compounds (6-methyl-5-hepten-2-one, 2-methylbutanal and 2-phenylethanol) than non-heated fruit, and they tasted better, Bai says. 

“Chilling suppresses production of oxygen, nitrogen and sulfur-containing heterocyclic compounds, ketones, alcohols and aldehydes, including 13 important aroma components of tomato flavor. But hot water-treated fruit actually produced higher concentrations of these important aroma contributors, even with subsequent chilling.”

Currently, they are monitoring flavor compounds at additional time points — when the tomatoes are green, soon after the process is performed and when they are partially ripened. This information will be combined with data on fully ripened tomatoes to help the team develop a better commercial process.
Bai says that his team’s approach is an easy, inexpensive fix to the flavor problem. 

Many post-harvest technologies sacrifice flavor to prevent bruising or spoiling, he points out. “Our methods can easily be implemented in the current commercial system without risking fruit decay,” he explains.
They also tried alternative methods to hot water, such as incubating green tomatoes with methyl salicylate, also known as wintergreen oil, an antifungal fumigant that is “generally recognized as safe” by the U.S. Food and Drug Administration.

He says he and his colleagues have successfully preserved flavor with another method, too. With this procedure, they picked the tomatoes at a later stage than growers usually do. Instead of picking them when they were all green, the researchers waited and collected them when the fruits were half-green and half-pink (the breaker stage). 

Then, they treated them with 1-methylcyclopropene (a gas approved by the U.S. Environmental Protection Agency). They did this to make the fruit more tolerant to cell death and deterioration at higher storage temperatures. Thus the chilling step was avoided and the flavor maintained. The researchers plan to closely compare the flavor-saving qualities of all techniques.

Once the researchers determine if one of the methods is better, they will approach food processing firms to determine if they are interested in adopting the technique, Bai says.


The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 158,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Hot Chilli May Unlock a New Treatment for Obesity


Newswise, August 19, 2015 — Newswise — University of Adelaide researchers have discovered a high-fat diet may impair important receptors located in the stomach that signal fullness.


Published today* in the journal PLOS ONE, researchers from the University’s Centre for Nutrition and Gastrointestinal Diseases (based at the South Australian Health and Medical Research Institute) investigated the association between hot chilli pepper receptors (TRPV1) in the stomach and the feeling of fullness, in laboratory studies.
“The stomach stretches when it is full, which activates nerves in the stomach to tell the body that it has had enough food. We found that this activation is regulated through hot chilli pepper or TRPV1 receptors,” says Associate Professor Amanda Page, Senior Research Fellow in the University of Adelaide’s School of Medicine and lead author on the paper.
“It is known from previous studies that capsaicin, found in hot chillies, reduces food intake in humans. And what we’ve discovered is that deletion of TRPV1 receptors dampens the response of gastric nerves to stretch – resulting in a delayed feeling of fullness and the consumption of more food. Therefore part of the effect of capsaicin on food intake may be mediated via the stomach.
“We also found that TRPV1 receptors can be disrupted in high fat diet induced obesity,” she says.
Dr Stephen Kentish says these findings will inform further studies and the development of new therapies.
“It’s exciting that we now know more about the TRPV1 receptor pathway and that the consumption of capsaicin may be able to prevent overeating through an action on nerves in the stomach,” says Dr Kentish, National Health and Medical Research Council (NHMRC) Fellow from the University of Adelaide’s School of Medicine.
“The next stage of research will involve investigation of the mechanisms behind TRPV1 receptor activation with the aim of developing a more palatable therapy.
“We will also do further work to determine why a high-fat diet de-sensitises TRPV1 receptors and investigate if we can reverse the damage,” he says.
This research was funded by the Blue Gum bequest, Royal Adelaide Hospital. 

Tuesday, August 18, 2015

Powdered Cranberry Combats Colon Cancer in Mice

BOSTON, Aug. 18, 2015 — Cranberries are often touted as a way to protect against urinary tract infections, but that may be just the beginning. Researchers fed cranberry extracts to mice with colon cancer and found that the tumors diminished in size and number. Identifying the therapeutic molecules in the tart fruit could lead to a better understanding of its anti-cancer potential, they say.
The team will describe their approach in one of more than 9,000 presentations at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society, taking place here through Thursday.
According to the American Cancer Society, one in 20 Americans will develop colon cancer at some point in his or her lifetime. While progress has been made on the detection and treatment of colon cancer, it remains the second leading cause of cancer-related deaths in the U.S.
Colon cancer may offer a particularly good target for a dietary treatment, says Catherine Neto, Ph.D., simply due to the anatomy of digestion. “Cranberry extracts may also afford protection toward other cancers, but it seems reasonable to look at colon cancer,” she says. “Cranberry constituents and metabolites should be bioavailable to the colon as digestion proceeds.”
In previous studies, Neto and colleagues at the University of Massachusetts, Dartmouth, found that chemicals derived from cranberry extracts could selectively kill off colon tumor cells in laboratory dishes. “We’ve identified several compounds in cranberry extracts over the years that seemed promising, but we’ve always wanted to look at what happens with the compounds in an animal model of cancer,” Neto says. This led to a collaboration with Hang Xiao, Ph.D., of the University of Massachusetts, Amherst. His team had developed a mouse model that mimics the type of colon cancer associated with colitis, an inflammatory bowel condition that affects hundreds of thousands of people in the U.S.
For Neto’s part, her team generated three powdered cranberry extracts: a whole fruit powder, an extract containing only the cranberry polyphenols, and one containing only the non-polyphenol components of the fruit. Some evidence suggests that polyphenols have anti-inflammatory properties, and she wanted to assess their contribution to the cranberry’s overall impact.
The researchers mixed the cranberry extracts into the meals of mice with colon cancer. She notes that the mice do not seem to mind the tart flavor. After 20 weeks, the mice given the whole cranberry extract had about half the number of tumors as mice that received no cranberry in their chow. The remaining tumors in the cranberry-fed mice were also smaller. Plus, the cranberry extracts seemed to reduce the levels of inflammation markers in the mice.
“Basically, what we found was pretty encouraging. All preparations were effective to some degree, but the whole cranberry extract was the most effective,” says Neto. “There may be some synergy between polyphenol and non-polyphenol constituents.” Neto’s graduate student Sarah Frade will present the work at the ACS meeting.
In the study, the researchers were careful not to give the mice an absurd amount of cranberry. “This is approximately equivalent to a cup a day of cranberries if you were a human instead of a mouse,” Neto says. However, she’s not sure someone could get the same benefits from juice, which lacks some of the components in the skin of the cranberry.
Currently, Neto is looking deeper into the cranberry to see if she can isolate individual components responsible for its anti-cancer properties. The researchers are also analyzing the metabolites in the mice that consumed the fruit extracts to better understand what happens due to mouse metabolism after the cranberry components are digested.
Neto acknowledges funding from the UMass President’s Science and Technology Initiative.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 158,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Monday, August 17, 2015

Nutrition Supplements Add Weight, not Longevity for Many Seniors

Newswise, August 17, 2015 — ST. LOUIS -- While taking nutritional supplements helps older adults in the general population gain weight, they don’t necessarily live longer or function better than those who don’t take supplements, according to a research review article by Saint Louis University geriatricians.

However, supplements improve the ability of those who are malnourished or frail to function and help them live longer.

Nutrition supplements are beverages such as Ensure or Boost that contain vitamins, minerals, proteins and calories and frequently are taken between meals, in addition to traditional foods.

Malnutrition in the elderly is a significant problem, affecting up to 15 percent of those in long-term care facilities, says Julie Gammack, M.D., professor of geriatrics and lead author of the article that was published early this year in Current Opinion in Clinical Nutrition and Metabolic Care.

“Malnutrition and weight loss are common and have serious consequence for older adults. It’s often under-recognized in the elderly population and its consequences can be devastating,” said Gammack, who also is a SLUCare Physician Group geriatrician.

“People lose strength and their ability to function independently, which puts them at risk of increased hospitalizations and their overall quality of life deteriorates. Oral nutritional supplements have shown benefits for those who are malnourished or frail.”

Long a leader in geriatric care, SLU recently received a $2.5 million, three-year federal grant to improve care for older Missourians. Read about it here.
Established in 1836, Saint Louis University School of Medicine has the distinction of awarding the first medical degree west of the Mississippi River. The school educates physicians and biomedical scientists, conducts medical research, and provides health care on a local, national and international level. Research at the school seeks new cures and treatments in five key areas: infectious disease, liver disease, cancer, heart/lung disease, and aging and brain disorders.

Sunday, August 16, 2015

Trans Fats, but Not Saturated Fats, Linked to Greater Risk of Death and Heart Disease

Newswise, August 16, 2015 — Hamilton, ON (August 11, 2015) – A study led by researchers at McMaster University has found that that trans fats are associated with greater risk of death and coronary heart disease, but saturated fats are not associated with an increased risk of death, heart disease, stroke, or Type 2 diabetes.
The findings were published today by the British Medical Journal (BMJ). The lead author is Russell de Souza, an assistant professor in the Department of Clinical Epidemiology and Biostatistics with the Michael G. DeGroote School of Medicine.
“For years everyone has been advised to cut out fats. Trans fats have no health benefits and pose a significant risk for heart disease, but the case for saturated fat is less clear,” said de Souza.
“That said, we aren’t advocating an increase of the allowance for saturated fats in dietary guidelines, as we don’t see evidence that higher limits would be specifically beneficial to health.”
Guidelines currently recommend that saturated fats are limited to less than 10 per cent, and trans fats to less than one per cent of energy, to reduce risk of heart disease and stroke.
Saturated fats come mainly from animal products, such as butter, cows’ milk, meat, salmon and egg yolks, and some plant products such as chocolate and palm oils. Trans unsaturated fats (trans fats) are mainly produced industrially from plant oils (a process known as hydrogenation) for use in margarine, snack foods and packaged baked goods.
Contrary to prevailing dietary advice, a recent evidence review found no excess cardiovascular risk associated with intake of saturated fat. In contrast, research suggests that industrial trans fats may increase the risk of coronary heart disease.
To help clarify these controversies, de Souza and colleagues analysed the results of 50 observational studies assessing the association between saturated and/or trans fats and health outcomes in adults.
Study design and quality were taken into account to minimise bias, and the certainty of associations were assessed using a recognized scoring method developed at McMaster.
The team found no clear association between higher intake of saturated fats and death for any reason, coronary heart disease (CHD), cardiovascular disease (CVD), ischemic stroke or type 2 diabetes.
However, consumption of industrial trans fats was associated with a 34 per cent increase in death for any reason, a 28 per cent increased risk of CHD mortality, and a 21 per cent increase in the risk of CHD.
Inconsistencies in the studies analysed meant that the researchers could not confirm an association between trans fats and type 2 diabetes. And, they found no clear association between trans fats and ischemic stroke.
The researchers stress that their results are based on observational studies, so no definitive conclusions can be drawn about cause and effect. However, the authors write that their analysis “confirms the findings of five previous systematic reviews of saturated and trans fats and CHD.”
De Souza, a registered dietitian, added that dietary guidelines for saturated and trans fatty acids “must carefully consider the effect of replacement foods.
“If we tell people to eat less saturated or trans fats, we need to offer a better choice. Unfortunately, in our review we were not able to find as much evidence as we would have liked for a best replacement choice, but ours and other studies suggest replacing foods high in these fats, such as high-fat or processed meats and donuts, with vegetable oils, nuts, and whole grains.”



Saturday, August 15, 2015

Fortified Against Blindness

Sweet potato varieties developed to increase vitamin A

Newswise, August 12, 2015 - Vitamin A deficiency is the leading cause of preventable blindness in children. It also increases the risk of disease and death from severe infections, according to the World Health Organization. About 250 million preschool children across the world are vitamin A deficient. 

Many of these live in Africa and South-Eastern Asia.

Fortunately, vitamin deficiency is preventable. In the United States, vitamin-fortified foods, like milk and cereals, are widely accepted. Another method, bio-fortification, is a crop-based option. This is the process of developing nutrient-rich varieties using molecular techniques or conventional breeding. The result is produce that provides better nutrition, right from the field.

Bio-fortification of sweet potatoes is a promising method to combat vitamin A deficiency in South Africa. The orange-fleshed vegetable already contains high levels of beta-carotene, which our bodies convert to vitamin A. Sweet potatoes are also a staple in the South African diet.

“Sweet potato is very popular in Africa,” says Sunette Laurie, a senior researcher with the Agricultural Research Council in Pretoria, South Africa. In South Africa, sweet potatoes are a traditional crop for rural families. 
“We realized it would be great if we could develop a local variety [of sweet potato] which has good yield, high dry mass, and desirable taste attributes, and promote it to combat vitamin A deficiency,” says Laurie.

“Those traits are actually very important. Africans prefer sweet potatoes with a higher dry matter content, a firm texture and a sweet taste,” says Laurie. Imported varieties were too moist, too low in dry matter content, or had low yield and could not adapt to South African growing conditions. 

“We had to start breeding projects to get the right attributes into the varieties,” says Laurie.

Laurie and her colleagues tested 12 varieties of sweet potatoes. Because growing conditions can vary widely, researchers planted in three different areas: humid subtropical, drier subtropical and temperate.

“We wanted a variety that could adapt to different climates,” says Laurie. “We were also aware of the possibility that consumers could have different taste preferences in the different provinces.” As a result, the researchers also set up tasting panels for the different varieties.

Two varieties, Impilo and Purple Sunset, are the most promising. Impilo adapted well to the different growing conditions, had acceptable dry mass, good taste, medium-sized roots for market, and a good yield. However, its light orange flesh means less beta-carotene. Purple Sunset is a darker-fleshed variety, but has lower yields and less adaptability to the different growing conditions.

According to Laurie, both varieties are widely accepted by farmers and consumers. They each go a long way in preventing vitamin A deficiency. A 4.4-ounce serving of Impilo provides 113% of the daily vitamin A requirement of a 4-8 year old. Purple Sunset provides 261%. A third variety, Bophelo, has higher beta-carotene than Impilo and fares better in taste tests.

Laurie is now involved in efforts to expand the use of these local varieties. Processing facilities are starting to use sweet potatoes to make flour, bread, muffins, and other products, all of which can help combat vitamin A deficiency across the continent. 

“There are so many options,” says Laurie, “and we are trying to get international development funds to set up more agro-processing units.”
In the meantime, Laurie and her colleagues are continuing to breed better varieties of sweet potatoes. 

“We would like to have varieties with more tolerance--to diseases, such as leaf and stem blight, and pests such as weevils,” she says. “Ideally we would be able to develop a variety that resembles Bophelo with more resistance.”

The study is published in Crop Science.