By Sharon Omahen
University of Georgia
For safety's sake, generations of babies have missed out on the sweet taste and healthy benefits of honey. But a new sterilization process may erase the risk and allow future toddlers to enjoy the sweet treat.
"Honey isn't recommended for babies because their immune systems are not developed," said Romeo Toledo, a food scientist with the University of Georgia College of Agricultural and Environmental Sciences.
Spores can survive
"The normal process for pasteurization of honey doesn't kill any (bacterial) spores present and could be a potential hazard for infant botulism," he said.
Eating honey poses no risk to adults with normal immune systems. But Clostridium botulinum spores found at very low levels in 5 percent to 10 percent of commercial honey samples can be deadly to infants.
For this reason, makers of children's medicines like cough syrups normally use sugar and corn syrup instead of honey as sweeteners, Toledo said.
Why is it so hard to kill the spores?
"Spores are the form bacteria take to lie dormant until the conditions are right for them to grow," Toledo said. "Because of this protective mechanism, spores are very resistant to killing by physical and chemical agents."
Honey's hard to heat
To kill the spores, processors must heat a product to at least 250 degrees Fahrenheit, under pressure, and hold it at this temperature for at least 3 minutes, Toledo said. But you can't do that to honey.
"You can't heat honey to very high temperatures because it burns, the flavor changes and some of the components that have health benefits are destroyed," he said. "The industry pasteurizes honey by heating it to 170 F and holding it there for 4 to 5 minutes, then hot-filling it into bottles and cooling it. This is adequate to destroy molds and common yeasts and prevents fermentation during storage."
But spores can survive this process.
With funding from the National Honey Board, Toledo developed a sterilization process called high pressure throttling, which kills spores in honey without affecting the honey.
"The process we developed produces honey that is free of Clostridium botulinum spores, so it can be used safely in pharmaceutical products and foods designed for infants," he said.
New process kills spores
Toledo's new sterilization process kills all microorganisms, vegetative cells and spores.
"Our process uses a combination of heat and high pressure to instantaneously kill the spores," he said. "Therefore, the flavor and other physical properties of the honey remain the same as in the raw honey."
The process pressurizes the honey to about 35,000 pounds per square inch and passes it very fast through a heat exchanger to raise its temperature to 180 degrees Fahrenheit within a few seconds. When the pressure is dropped, the temperature instantly spikes to about 275 degrees. The honey is then cooled within seconds.
"We instantaneously raise the temperature to kill the spores," Toledo said. "Exposure time at the high temperature is just a few seconds. We produce a sterile product with all the natural nutrients retained."
Honey industry interested
The honey industry is very interested in the process, which UGA patented last year. The next step is to develop the prototype machines for use in processing plants.
"The food industry traditionally takes about 10 years to adopt new techniques like this one," Toledo said. "We're in our fifth year with this new process, so we're well on our way."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)