Antimicrobial activity of lysozyme and lactoferrin incorporated in cellulose-based food packaging

The antimicrobial proteins lysozyme and lactoferrin were incorporated into paper containing carboxymethyl cellulose, that allowed non-covalent binding of the positively charged proteins to the paper matrix. More than 60 percent of the proteins added alone or in combination during the papermaking process were released in buffered saline.The released proteins retained their structural and functional features, indicating that the papermaking process did not affect their structure. The antimicrobial activity on common food contaminants was also retained in the released protein, and a synergism between the two proteins was evident in tests carried out with paper containing both proteins against Listeria.Tests on thin meat slices laid on paper sheets containing either or both antimicrobial proteins indicated that lysozyme was most effective in preventing growth of this particular microbiota.

► Lysozyme and lactoferrin retain structure and activity after incorporation in paper. ► Addition of carboxymethyl cellulose improves the protein payload of paper. ► Both proteins are released under conditions similar to those encountered in real food. ► The released antimicrobial proteins may act synergically on some microorganisms. ► Tests on thin cuts of raw meat confirmed the antimicrobial effect.