Novel technologies on the horizon
What’s the next big thing in food safety? WSU food safety and microbiology researcher Minto Michael offers insight into emerging tech and low-water activity food processing.
Minto Michael never planned to become a scientist.?
Growing up in India, he dreamed of becoming an electrical engineer. He wanted to write code and build robots. But something unexpected happened in his first semester of college: He ended up in an introductory food science course. Influenced by a passionate professor, he chose to change his major to food science and re-envision his future.?
"As an engineer, I hated microbiology," Michael said. "But within a few months, I just fell in love with microbiology and I was very happy to give up my engineering and start working in microbiology."
When he came to the United States to pursue a graduate degree at Kansas State University, he found himself working in the Food Safety and Defense Laboratory. It was there that he got his start studying pathogens in low water activity foods, such as pet food, milk powder, and flour. He also worked with probiotics.?
During that time, he decided to get a PhD and focus his career on food safety and microbiology. Today he leads a microbiology and food safety research lab at Washington State University, where he continues to study low water activity food and emerging food safety technologies.?
Low moisture, no problem?
“When people talk about low water activity food, lots of times they refer to them as comparatively safe food,” he said. “That's what the perception is – and that's fine if you look at it from one angle, but just having low water activity doesn't guarantee food safety.”
Low moisture foods can still harbor pathogens, such as E. coli, salmonella, and listeria, that can survive for long periods of time in low water activity environments. These pathogens do not form spores, but they adapt to the harsh conditions by increasing the solute content inside their cells and stopping their multiplication.?
"They are not dying in low water activity food products," he says. "The only thing that's happening is that they're not multiplying."?
Once these products are hydrated or reconstituted, the pathogens can resume their growth and cause illness. Therefore, the best way to ensure the safety of low moisture foods is to prevent their contamination in the first place.?
The problem is, traditional heating methods are often insufficient or detrimental to the quality of low moisture foods, because they require higher temperatures or longer times to kill the pathogens. Michael suggests using novel technologies, such as radio frequency heating or irradiation, to enhance the efficacy and efficiency of thermal inactivation.?
"If you want to kill pathogens and you still want to preserve the quality of your food," he says. "I personally think irradiation is the best technique to improve the safety of low water activity powders like milk powders or flour."
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New food safety frontiers: Hyperspectral imaging and nanobubbles
Michael’s research in the WSU lab isn’t limited to low water activity foods. His recent research includes several novel food safety technologies, some of which he believes could be the next big thing in food manufacturing.
“The first one is called hyperspectral imaging. It’s a technique where we combine regular photography with spectroscopy so we can get two types of data. We take photographs of either bacterial cells or bacterial colonies and try to identify if they’re E. coli, salmonella, listeria, and so forth,” Michael said.
Traditional microbiological methods take two to six days to positively identify bacteria. Hyperspectral imaging can do it within a few minutes. The technology has widely accepted agricultural and military applications, but remains obscure in the food industry.? There’s just one problem yet to be resolved: Right now, the process requires enrichment, which can take 18-24 hours, before imaging can be performed.
“The second technology my lab is working on is nanobubbles,” Michael said. “We introduce nanoscale bubbles into food matrices or elsewhere and use those nanobubbles to achieve various effects.”?
Michael uses the nanobubbles in two ways: to kill pathogens and to preserve probiotics. He said that he incorporates nanobubbles in antimicrobial solutions, such as chlorine water or acidic water, to increase their potency.?
“We can significantly increase the potency of the kill,” he said. “You can use the same concentration, but you’re going to get way more log reductions.”?
He also incorporates nanobubbles into milk to increase the longevity of probiotics in fermented products, such as yogurt or kefir. He said that nanobubbles may also have potential in improving the textural quality of food products.
These novel technologies, in addition to more well known (though often misunderstood) tools like water activity, could offer significant advantages for food quality and safety managers who work with dairy products or other food matrices.?
Michael suggested that food quality and safety managers should explore the potential of these technologies and consider implementing them in their processing and preservation operations.
“There are many things that could be the next big thing, depending upon the researcher and the group you talk to,” he said. “But based on my knowledge, I think these have great potential to improve the future of food processing.”
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