Researchers at the University of Arkansas have found another tool for fighting foodborne pathogens. By activating lactoferrin, an antimicrobial compound, they were able to reduce Listeria monocytogenes to nondetectable levels.
Listeria monocytogenes is a bacterium that can cause the disease listeriosis, which is marked by flu-like symptoms and can spread to the nervous system.
Listeria monocytogenes was the most sensitive to lactoferrin activated by citric, malic and lactic acids in combination with the chelator EDTA, said Navam Hettiarachcy, a food science professor who led the research project for the Food Safety Consortium. Chelators are compounds of metal ion that form rings.
Although lactoferrins level of effectiveness against E. coli O157:H7 wasnt as great as its ability to reduce Listeria monocytogenes to nondetectable levels, it still was significantly effective against E. coli by eliminating at least 99 percent of the pathogen. Infections from E. coli O157:H7 can lead to severe diarrhea and abdominal cramps and can be fatal in some cases, especially among children under 5 years of age.
Federal regulators several years ago authorized spraying lactoferrin on beef to control E. coli. Microbial growth on meat and meat products occurs primarily at their surfaces, so other researchers had previously studied the effects of spraying lactoferrin on the surfaces. But the direct application had limited benefits because the active substances would neutralize or would rapidly diffuse into the tissue.
Interaction of lactoferrin with food components will reduce its antimicrobial effectiveness, Hettiarachchy explained.
Other research, however, had also shown that antimicrobial substances could be successfully incorporated into an edible film covering meat surfaces and would be effective. That prompted Hettiarachchys team to examine whether using lactoferrin in this manner would be effective.
Incorporation of lactoferrin into film will prevent diffusion of the lactoferrin into the meat and still maintain its antimicrobial activity on the surface, Hettiarachchy said. This will provide a continuous barrier to contamination by pathogens on foods up to the time of consumption.
Hettiarachchy added that research is still in progress seeking a film matrix suitable to maintain the effectiveness level in the coating.
Lactoferrin is also consumer friendly since it is derived from milk, she added, and consumers are aware of its benefits as a protein.
Source: University of Arkansas