Activated lactoferrin deters pathogens on food surfaces.

While we have known for a long time that natural antimicrobial agents exist in milk, eggs, plants and probiotics, we've only gained an understanding about the structure-function relationship of these bioactive compounds in recent years. One of these compounds is lactoferrin, which is a bioactive glycoprotein found in milk.

The ability of lactoferrin to bind two iron ions that have high affinity with two hydrogen-carbon-oxygen ions contributes to its major structure-function properties, including its antimicrobial activity. This binding ability plays an important role in regulating physiological pathways. These attributes give lactoferrin application as a food antimicrobial material.

The antimicrobial functionality of lactoferrin depends on its protein conformation and milieu conditions. Its bacteriostasic effect enhances when it binds to a microbial cell surface. Specific lactoferrin-binding targets exist in some Gram-positive and Gram-negative bacteria. The high-affinity interaction of lactoferrin with pore-forming outer membrane proteins of Gram-negative enterics, including E. coli, is significant for the antimicrobial outcome of lactoferrin.

The interaction of lactoferrin with microbial surfaces, namely the outer membrane proteins of Gram-negative bacteria, is what triggers its antimicrobial mechanisms, such as the inhibition of microbial attachment to subepithelial matrix proteins and the detachment of bacteria from mucosal surfaces. By discovering how to activate the lactoferrin molecule, scientists are able to mimic its function on meat samples.

Activated lactoferrin becomes a microbial blocking agent that interferes with microbial adhesion and colonization. It detaches live or dead microorganisms from biological surfaces, inhibits microbial growth and multiplication, and neutralizes the activity of endotoxins.

Activated lactoferrin has demonstrated microbial blocking activity against such pathogens as E. coli O157:H7, L. monocytogenes, Salomonella spp., Campylobacter spp., Vibrio spp., S. aureus, Bacillus spp. and Pseudomonas spp., as well as radiation-resistant bacteria. The substance also inhibits yeasts and molds. Potential intervention applications include poultry, pork, seafood and produce.

Activated lactoferrin can be applied to meat products at the processing plant as an added step to a company's multiple-hurdle bacterial control process. Because lactoferrin remains on the meat surface, the compound may provide lasting protection from bacterial exposure after processing.

Further information. Narain Naidu, N-terminus Research Laboratory, 981 Corporate Center Dr., Pomona, CA 91768; phone: [phone]; fax: [phone]; URL: www.activatedlactoferrin.com.