A new North Carolina study connected cooking with science, examining how fermented foods like kombucha and kimchi – which have had a huge surge in popularity in recent years – not only taste good but are also good for you.
In a series of science workshops at the North Carolina Museum of Natural Sciences, scientists and chefs taught K-12 teachers and others how to make fermented foods. Each workshop focused on a specific fermented food: kimchi, chow chow and kombucha.
“The chefs would come in, and we had scientists as well as all of the museum participants. We had everybody create some of these jars of food or in the kombucha option, jars of tea and we would create those in the museum setting. Participants would take them home so that they could have something delicious to enjoy," said study co-author Dr. Julie Horvath, "And then we would take a duplicate set that the public made and put them in the genomics and microbiology lab window where we could allow other visitors to learn more about the process. And then we could also sample them daily when we needed to collect samples for our experiments.”
Horvath is a geneticist at N.C. State and a researcher at the North Carolina Museum of Natural Sciences. She said Kombucha actually dates back more than 2,000 years, so the tea isn’t just a new fad or social media trend. It’s a fermented drink made from either black or green tea, sugar, “healthy” bacteria, and yeast. It’s usually fermented anywhere from a week to a month.
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“A lot of fermented foods have been around for thousands of years. So, we were kind of just using some of these common foods that people have thought of, maybe haven't always realized that they were fermented or beneficial to their health in certain ways," she explained, "And so, we wanted to kind of get people to think through the benefits of microbes and how that can actually impact their health.”
According to the Cleveland Clinic, limited studies have shown it can limit inflammation, boost gut health, and ward off heart problems, cancers, and high cholesterol.
Kimchi is a fermented Korean dish made from cabbage, garlic and other spices, and vegetables. The clinic says it can also improve gut health, keep you regular, as well as curb colon cancer risk and improve heart health.
Chow Chow, or chayote squash, was also used in the experiment; it has probiotics that improve digestion, support a healthy immune system, and small studies have shown it may also influence mental health and reduce inflammation.
Horvath said the study found that kimchi made with cabbage fosters very different microbial communities compared to kimchi made with daikon radishes.
“if you looked at kimchi that was made with primarily cabbage, you know, you had different microbes in it than if it was made with a type of radish. That has been shown before, but that was exciting because now we're verifying that participants can actually help and we're getting valuable scientific information," she said.
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In kombucha, on the other hand, the same did not hold true. Horvath said, “Kombucha, which was one of my favorites, was kind of interesting because we included both green tea and black tea and those are made through different processes. So black tea is fully oxidized and so it has a lot of more polyphenols in it, has a stronger, richer, bolder flavor, whereas green tea has a lot more plant antioxidants and kind of people call it a grassier flavor. So, it was interesting that we didn't see very many microbe species differences between the green and the black tea, or if we mixed the amounts of how much green or black tea was in one of the kombucha jars.”
She said the study was intended to help people understand the beneficial roles that microbes play in the food systems.
“It's important to understand that there are some organisms like lactobacillus organisms that actually become more prominent in the fermented food and those reduce the pH and actually then that helps exclude some of the pathogenic or harmful bacteria," Horvath said, "So having those lactobacillus organisms is beneficial to not only making that food product safe to eat, but also beneficial to the overall health because those lactobacillus organisms are beneficial to gut health.”
The paper, “Cooking-Class Style Fermentation as a Context for Co-created Science and Engagement,” is published open access in the journal Microbiology Spectrum.
