A ‘souper’ partnership

Standing in her white lab coat with the blue safety gloves, Erin Kelley gently held a container of packaged soup, inspecting it carefully for signs of initial spoilage.

A bulging container? Nope. Normal color? You bet. Smell? Normal – whatever that is.  

The container passed this inspection before moving on to a more thorough second round that involves more scientific methods.   

A junior in the Department of Food Science and Technology at Virginia Tech, Kelley, from Santa Fe, New Mexico, is a member of Alexis Hamilton’s food microbiology lab in the College of Agriculture and Life Sciences.

As a Virginia Cooperative Extension Specialist, Hamilton routinely works across the commonwealth to help companies and individuals improve their food safety. When one of her industry partners, a local Washington, D.C.-based woman-owned business called Soupergirl, shared that they wanted to expand the distribution of their soups by increasing the shelf life, Hamilton instantly saw how she – and her talented lab of students – could contribute.

Many soups use salts and other preservatives to increase shelf-life. Soupergirl wants to increase the shelf-life of their soups while keeping a “clean label,” or ingredients that are found in most kitchens or pantries, explained Sara Polon, who co-founded Soupergirl with her mother. Notably, this does include some naturally occurring preservatives.  

Hamilton’s lab is helping Soupergirl by testing her soups at various stages of product distribution, looking at the pH, sensory qualities, and much more. The data gathered could be used to slightly tweak the soup formulas to extend shelf life in stores. Currently, the shelf life of the soups stands at 56 days. An increase of just three days could have a profound impact on the business.

With soups in stores from Florida up to Maine – the entire East Coast – an increase in shelf life means expansion can head westward. Because it can take more than two weeks for the soups to make it into a supermarket, Polon is hoping Virginia Tech can help show that new formulations can extend that 56-day shelf life, while maintaining flavor, texture, and more.

“Virginia Tech is doing incredible work on the research frontier, helping the community, and educating the next generation of food safety experts and researchers,” Polon said. “I’m grateful for the opportunity to work with the food safety program and help students gain practical, hands-on experience.”  

The partnership was born from the Food Producer Technical Assistance Network, led by Melissa Wright, at Virginia Tech. What started with a very simple question of “How do I make a safe food product?” has blossomed into a collaboration to enhance the shelf life, quality, safety, and distribution reach of a product.

“I am really fortunate to have a strong team of student researchers,” Hamilton said. “Undergraduate, graduate, and some postgraduate students work in my lab, and what they're getting to do with this project is take some of those fundamental microbiology concepts that we learn in the classroom and apply that in a practical way that they would very likely see in the industry, which prepares them for the workforce.”

This project has provided students a unique professional development opportunity.  

“They've gotten to work with materials that the industry uses and that we typically don't see in a teaching laboratory,” Hamilton said. “Very often, they've gotten to build their own professional development and technical training skills. They've worked on science communication and how they might switch between talking about data in the lab and interpreting what it means in the boardroom.”

For Chrissy Walsky ’23, a technician in the lab, the project has been an opportunity to build on her undergraduate work at Virginia Tech and prepare for graduate school through hands-on, applied experiences.  

“This has been a new and exciting opportunity to work with an industry partner,” said Walsky, who majored in animal sciences and microbiology at Virginia Tech and was in FFA growing up. “This is my first time working directly with a business and it’s been great to see how the scientific work we do helps industry.”

A passion for food science led Walsky, who is from Fredrick, Maryland, down this path, as well as a desire to ensure the food people eat is safe.

“I am very fortunate to be supported by food science and technology since it wasn’t my department as an undergraduate,” Walsky said. “Everyone here has taught me a lot. I'm still learning every day. Being on a team like this has exposed me to so many different skill sets and ways to work with different people. These are all valuable research skills, whether it’s in industry or higher education.”

There are numerous ways that a food product can be made safe, and Hamilton’s lab looks for indications that a product is changing over time and could spoil before a customer eats it.  

“One of the ways that small businesses can be strong competitors is through the quality of their products,” said Isa Maria Reynoso, who is from the Philippines and pursuing her Ph.D. at Virginia Tech. “Our work in the lab will help Soupergirl be even more competitive.”

An intra-departmental connection

Ensuring that the product tastes and smells the same is an important component of the project that is handled through a departmental collaboration with the Sensory Evaluation Lab. Renata Carneiro, a research assistant professor in the department, is leading the sensory evaluation course that has a hands-on, service-learning component.  

Divided into two groups, the course looks at potential new flavors of soups, as well as how soups could be perceived by consumers at various stages of shelf life, through a research project that involves volunteers.

“These are juniors and seniors solving real industry problems and leading a real project with real consequences,” Carneiro said. “The students see that they can run and conduct projects such as this. It’s a great opportunity for them to use the knowledge they’ve gained.”

This lab has done exactly that for Sophie Miller, a junior from Stafford, Virginia. It built upon her previous coursework into an experience that provided hands-on research.

The project and sampling was divided into groups, each assigned a different soup. For the data collection process - the first time that Miller had gone through the Institutional Review Board - was a chance for students to work with human participants.

The participants were given samples of the soup, one at a time, and surveyed on their flavor preferences at various stages of shelf life.

“This class and project will help me and as a future food scientist,” Miller said. “At the end of the day, I want to make a product that will be successful on the shelves of a grocery store and that consumers enjoy. Being able to learn about the sensory tests and how to conduct studies with participants helps me in my future career.”

After a product is received on any one of the sample days, the ultimate goal is to see what microorganisms are present in that product that might impact its shelf life over time. First, the research team brings that product into the lab out of storage, whether that's stored at ambient room temperature or refrigerated.

Next, a portion is weighed out, diluted, and placed on Petrifilm. The lab team then goes through the process of dilution, plating, and incubation. 

The team finally looks for the number and type of microorganisms that show up on the film, with thresholds that indicate the quality of the product for consumption. 

Soupergirl, a Washington, D.C.-based soup company that launched in 2008, is Sara Polon, a former stand-up comedian turned soup-maker/CEO and her mom, Marilyn Polon, a home-taught pro in the kitchen.