(By Dr. Joseph D. Lim and Dr. Kenneth Lester Lim, BS-MMG, DDM, MSc-OI)
INGREDIENTS used in making food products can thicken and reduce saliva.
It is one way of decreasing the transmission potential of airborne pathogens like those that cause COVID-19, say researchers at the University of Central Florida (UCF).
The researchers – Michael Kinzel, PhD, and Kareem Ahmed, PhD – looked at combinations of food products that alters people’s saliva. The results of their study are published in the journal Nature Scientific Reports.
“This is a new concept in the context of source control,” says Dr. Kinzel, an Assistant Professor in UCF’s Department of Mechanical and Aerospace Engineering and the study co-author. “There are obviously masks, but this is the first research focusing on what comes out of one’s buccal cavity or mouth.”
The work builds on the Dr. Kinzel and Dr. Ahmed’s previous studies examining the effectiveness of masks in the classroom, features that could make someone a super spreader, and initial studies of food ingredients to control airborne disease transmission.
Dr. Ahmed is an Associate Professor in UCF’s Department of Mechanical and Aerospace Engineering.
“The group has researched droplet formation for years,” Dr. Kinzel says. “When we heard sneezes transported aerosols over 27 feet early in the pandemic, we realized that this has to be small aerosols, similar to what you see in a misting nozzle. Our thinking has been, let’s focus on altering those droplets such that they fall to the ground and not travel so far.”
The researchers examined the characteristics of saliva, such as thickness and amount, and their influence on how far droplets and aerosols from a human’s sneeze travel, which are factors related to airborne pathogen transmission.
They used high-speed cameras to capture the sneezes frame-by-frame in mid-air. Then they employed image processing software to quantify droplets and aerosols.
Subsequent numerical methods using computational fluid dynamics provided the minute details to better understand sneeze events.
Saliva was altered using a range of food-grade compounds, including cornstarch, agar agar, xanthan gum and ginger.
The researchers found that ginger reduced the amount of saliva expelled from a sneeze by more than 80 percent and was as effective as a mask in reducing the distance of droplets and aerosols from a sneeze.
Cornstarch and xanthan gum were found to increase the thickness of saliva by 5 percent and 2,000 percent, respectively. They also reduced the distance of aerosols from a sneeze more than not wearing a mask.
However, a mask was still more effective in reducing aerosol distance than cornstarch and xanthan gum.
A neck scarf combined with a surgical mask was the type of mask used in the study.
The findings suggest that certain food products can be tailored to both thicken and reduce saliva emitted to reduce airborne transmission. This can also be used in combination with a mask, or without as the impact of the pandemic changes, and could perhaps allow for increased capacity, Dr. Kinzel says in a UCF press release.
One such product could be a chocolate to deliver the saliva changing compound.
“Much like vitamin gummies, this would not be a candy, but rather a form to deliver the solution,” Dr. Kinzel says. “It could perhaps be referred to as a ‘chocaceutical.’”
The research was funded in part by the Division of Chemical, Bioengineering, Environmental, and Transport Systems, Fluid Dynamics at the U.S. National Science Foundation.
The study co-authors were Jonathan Reyes, a postdoctoral researcher in UCF’s Department of Mechanical and Aerospace Engineering who works in Ahmed’s lab; Douglas Fontes, a postdoctoral researcher with the Florida Space Institute; Alexander Bazzi, a graduate student in UCF’s master’s program in mechanical and aerospace engineering; and Michelle Otero, a graduate of UCF’s doctoral program in mechanical engineering.
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Dr. Joseph D. Lim is the former Associate Dean of the College of Dentistry, University of the East; former Dean, College of Dentistry, National University; Past President and Honorary Fellow of the Asian Oral Implant Academy; Honorary Fellow of the Japan College of Oral Implantologists; and Honorary Life Member of the Thai Association of Dental Implantology. For questions on dental health, e-mail jdlim2008@gmail.com or text 0917-8591515./PN
