Researchers find sustainable sanitizer to reduce salmonella on produce
Texas A&M study reveals how upcycled probiotic production waste can reduce foodborne risk
Food scientists in the Texas A&M College of Agriculture and Life Sciences have found a way to make fresh produce safer, using what most would throw away.
Texas A&M AgriLife Research scientists in the Department of Food Science and Technology found that leftover liquid from probiotic fermentation, known as fermentation waste broth, can be upcycled to reduce foodborne pathogens.
The breakthrough by Seockmo Ku, Ph.D., assistant professor of food science, who led the study with doctoral student Min Ji Jang, both in the Department of Food Science and Technology, was recently published in the Chemical Engineering Journal.
Paired with mild heat, broth from probiotic production, significantly reduced salmonella counts and microbial levels on fresh radish sprouts. The method provides a safe and sustainable alternative to chemical sanitizers.
The findings mark a notable achievement upcycling the discarded waste broth as a food sanitizer, contributing to the sustainable production of probiotics, Ku said.
From waste to food safety solution
The production of probiotics generates thousands of gallons of nutrient-rich broth that’s typically discarded, said Ku.
“We wanted to know whether this food-grade byproduct could be repurposed to improve food safety instead of ending up as waste,” he said.
The probiotic waste broth also contains a lot of postbiotic materials produced by probiotic fermentation that might also be used for various purposes.
Ku and Jang developed the process to enhance the antimicrobial properties of the probiotic broth. The team treated the leftover liquid from Lactiplantibacillus plantarum, a common probiotic species, at 113 degrees, a gentle heat compared to typical sanitization methods.
The resulting method, known as “CFS-MH” for cell-free supernatant plus mild heat, reduced salmonella typhimurium by more than five log colony forming units in laboratory tests, equivalent to a millionfold reduction.
In fresh sprouts, the treatment lowered food hygiene indicators, total bacteria and coliform counts by up to 3 log colony-forming units, and maintained those reductions during a week of refrigerated storage. Neither mild heat nor the probiotic broth alone achieved the same results, suggesting a synergistic antimicrobial effect.
“The mild heat helps the organic acids in the probiotic broth penetrate bacterial cell walls more effectively,” Jang said. “It’s a simple, low-energy process that produce handlers could adopt without using harsh chemicals.”
Recognized for innovation and sustainability
The researchers also assessed the economic and environmental impact of the process. Upcycling 1,056 gallons of waste broth from a 1,320-gallon probiotic fermentation could generate about $100 in value per batch — comparable to sodium hypochlorite sanitizers — while reducing waste transport and disposal costs.
The publication underscores the significance of sustainability innovations in probiotic supplement production within the broader food industry field, Ku said about his and Jang’s research.
“It shows that interdisciplinary thinking can create solutions for safer, more sustainable food systems,” he added.
The study was supported by the U.S. Department of Agriculture National Institute of Food and Agriculture, Islamic Food and Nutrition Council of America, and the World Institute of Kimchi in South Korea.
