Improving the Taste of Catfish

People aren’t eating as much American-grown catfish as they did at the turn of the century. Studies show this is due, in part, to naturally occurring chemicals that create an off-flavor in the meat. Researchers at the ARS Food Processing and Sensory Quality (FPSQ) research unit in New Orleans, LA, are conducting research to ensure better quality of U.S. catfish.

Chemicals from blue-green algae blooms are the primary culprit in producing the off-flavor, but it can also come from other microbes. Fish largely collect these chemicals through their gills, but researchers have found an oral route as well.

The researchers are trying various management practices to reduce the amount of the off-flavor compounds, including “depuration” (placing fish in holding tanks of clean water to allow them to purge whatever off-flavors they may have absorbed), applying food-safe acids that are known to break down some off-flavors, and using ultraviolet-C (UVC) light during packaging. UVC kills some bacteria and reduces spoilage.

Landing a solution to the off-flavor problem is a work in progress, but scientists have plenty of reason to keep trying; studies show that retail sales of U.S. catfish have increased 22% in the past 5 years.

Insect Eaters: Turning Pests into Chicken Feed

It's that time of year when mosquitoes are everywhere. Their feasting on your blood can be an itchy nuisance and, in some cases, a serious danger. But  a team of enterprising ARS scientists are looking  to turn the tables on mosquitoes and other insect pests like house flies by making them into lunch for other animals.

The idea of farming insects as an animal food source was already the subject of an ARS initiative but this project added a new dimension, by specifically proposing the use of nuisance insects like mosquitoes, which are abundant in agricultural settings, as the insect food source – not so much killing two birds with one stone as feeding many birds with one pest. In fact, chickens seem to vastly prefer mosquitoes to their current feed. What to know more?

Check out Harvesting Agriculture's "Natural" Insect Farms. 

Take the Apple Seed Challenge

Do different types of apples have the same number of seeds? Join student and future scientist Lexlyn Cravens of the Chesapeake Math and IT Elementary School in Laurel, MD, to find out. Let's get counting!

Working to Keep the Chesapeake Bay Healthy

The Chesapeake Bay is the largest and most productive estuary in the United States and third largest in the world. Approximately half the water in the Bay comes from its 64,000 square mile watershed. A watershed is an area of land that can contribute water into a stream, river, lake, or bay. The Chesapeake Bay's watershed includes land in all or part of six states, from New York to Virginia. That's a lot of land, and as you can imagine over time urban development, agriculture, and industrialization in those areas have affected the water quality of the Bay's watershed.

The Bay has regional, national, and global importance—providing food sources, recreational opportunities, and access to major shipping routes. It is vitally  important to protect it from the harmful effects of pollution and climate change. ARS scientists are conducting research to better understand the Bay's ecosystem (e.g., water quality, soil health, wildlife habitat, food production). This will benefit not only the United States, but also conservation efforts in the other global estuaries, like the Baltic Sea.

You can learn more in "Improving the Water Quality of the Chesapeake Bay".

Inside the Bite

ARS entomologist Elaine Backus is improving our understanding of how mosquitoes feed. Using a technique known as electropenetrography (EPG), Backus attaches an electrode to both a human host and a mosquito. When the mosquito bites, a circuit forms, allowing researchers to measure all kinds of information about the bite, from how long it lasts and what the stages are to differences between male and female mosquitoes’ bites.

Although the technique was originally developed to examine how pests feed on crop plants, Backus and her colleagues expanded it to understand blood-sucking insects, including mosquitoes, ticks, and more. They hope that their research will aid in the fight against the negative effects of mosquito bites, from itchy irritation to disease transmission. Watch this video to learn more about their work. 

Using More Cotton May Help Clean the Environment

Cotton is biodegradable, while synthetic fibers contribute to pollution

Nonwoven textiles are made from loose fibers in a high-speed process. They are mostly used for single-use disposable products such as wipes, diapers, disposable masks, bandages, and surgical gowns. A research team at the ARS Southern Regional Research Center in New Orleans, LA, is looking at ways to increase the use and utility of cotton fibers.

Cotton accounted for less than 7% of the fibers used in nonwoven products, while synthetic and other fibers comprised the rest. The problem is that synthetic fibers, like polyester and polypropylene (which are, essentially, plastics), persist in the environment for decades and contribute to pollution, especially in marine environments.

Consumers recognize this as an environmental hazard and are seeking greener, sustainable, and biodegradable products. Farmers, producers, and consumers benefit from a natural and sustainable product and the environment benefits from less plastic pollution.

Read "Improving the Sustainability and Value of Cotton’s Natural Fibers" if you want to learn more.

Elephant Toothpaste

Scientists use hydrogen peroxide to sanitize and clean surfaces in their labs. One of the reasons we use hydrogen peroxide is because it does not leave any residue. Once exposed to UV light/the sun it breaks down into oxygen and water. This is also why bottles of hydrogen peroxide come in dark opaque bottles. This reaction happens slowly over time. However, we can make this happen more rapidly with a catalyst. Yeast is an organism that we use to make bread and test different strains of wheat in our wheat quality laboratories. Yeast produces such a catalyst that breaks down hydrogen peroxide. This is the same enzyme/catalyst that causes the peroxide to bubble when we put it on a cut or scrape. Catalase is present in most living things that have access to oxygen and helps them break down naturally occurring hydrogen peroxide.

About the Experiment

For this experiment, we're going to find out. What happens if we put hydrogen peroxide and yeast together in a large quantity? What if we added dish soap and food coloring? How does that change the outcome? It's time to get your hands messy like a scientist!

	Details Ages - 5-12
	Time - 15 minutes
	Difficulty - Easy

 What You'll Need

• Empty bottle or clear vessel. Try different sized vessels for different outcomes!
• 3% hydrogen peroxide (this is the typical concentration found in stores)
• Dry yeast
• Liquid dish soap (any color works)
• Food coloring (any color works)
• Warm water
• Cookie sheet or large tray
• Measuring cups and spoons
• Safety glasses!

Before you begin: Ask a parent or adult to assist. This is a fun but messy experiment, so you may want to consider doing it outside. However, it can be done in a kitchen or bathroom. Be careful with the ingredients, as hydrogen peroxide can bleach fabrics and food coloring can stain clothing. Wear clothing that you don't mind getting "dirty" or wear an apron or lab coat!

Let's Do This!

1. Add 1 tablespoon of dish soap into your bottle or vessel (Fig 1).
2. Measure ½ cup of hydrogen peroxide and pour into your vessel with the dish soap (Fig 2).
3. Swirl to mix.
4. Add 10 drops of food coloring (your choice of color) either into the mixture or pour along the sides of the bottle or vessel (Fig 3).
5. Place a cookie sheet or large tray under your bottle/vessel.
6. In a separate cup, mix one tablespoon yeast and three tablespoons warm water and stir until you have a uniform slurry (Fig 4).

7. Quickly pour the yeast mixture into the vessel and step back and watch!

Let's Look At The Results!

Clean up:

The end-result that looks like toothpaste is safe to wash down the drain with water or put in the trash.  If you got any toothpaste on your clothes or skin, rinse in cool water. The bottle/vessel and measuring tools can be cleaned with warm soapy water or placed in a dishwasher.

What did you learn?

• Did the experiment occur like you expected? Why or why not?
• What causes the mixture ooze out of the bottle/vessel?
• What else is hydrogen peroxide used for?

Additional experiments:

Try doubling the recipe or using half the dish soap. Use more or less food coloring, and either shake it vigorously or do not shake at all.

How do these modifications affect the outcomes?

• What happens if you add more or less food coloring?
• What happens if you mix the bottle/vessel lighter or more vigorously?

Can Grass Be Used to Eradicate Pests?

Pests are a major problem for our food growers, causing millions in damage and lost products. Nematodes – these tiny worm-looking things that feed on the root of plants – can be especially troublesome for organic farmers because pesticides are often the most effective way to manage these pests. However, ARS researchers found an effective, organic treatment against nematodes and other pests that uses orchard grass.

Read Killing the Crop Killers—Organically to learn more.

Women Play Leading Role in Ag Science

The United States began honoring women’s history in 1980, but ARS has a long tradition of celebrating the role of women in science. Women have been leading cutting-edge scientific research for decades, and many have been enshrined in the ARS Science Hall of Fame.

Here are just a few examples of current women working in ARS projects:

Beth Newingham is a research ecologist at the ARS Great Basin Rangelands Research unit in Reno, NV. Newingham is studying rangeland restoration after wildfires in the Great Basin.

Tracy Leskey, entomologist and director of the ARS Appalachian Fruit Research Station in Kearneysville, WV, is leading research into controlling the invasive brown marmorated stink bug, a major pest of many key crops.

Soheila Maleki is a research chemist with the ARS Food Processing and Sensory Quality Research unit in New Orleans, LA. She is searching for a treatment for peanut and tree nut allergies.

Revathi Shanmugasundaram is a biologist at the ARS Toxicology and Mycotoxin Research unit in Athens, GA. Shanmugasundaram is conducting research into whether mycotoxins in poultry feed could predispose chickens to fatal disease, even at low levels.

Hannah Rivedal is a plant pathologist at the ARS Forage Seed and Cereal Research unit in Corvallis, OR. She is working with scientists at Oregon State University and other institutions to help growers fight diseases of hemp and mitigate the damage they cause.

Emily Watkins de Jong is a biological technician conducting research into honeybee nutrition and health at the Carl Hayden Bee Research Center in Tucson, AZ.