Antimicrobial activity of copper ‐humate‐cellulose sheets

Test sheets containing copper and humate show antibacterial and antifungal activity. A new, modified disk diffusion test can detect the antimicrobial activity of slow diffusion packaging materials. Humate help to increase copper content of test sheets. During our research, cellulose ‐based test sheets containing copper and potassium humate were prepared and tested against several bacterial and fungal strains. The energy dispersive X‐ray spectrometry and attenuated total reflectance (ATR) Fourier‐transform infrared spectroscopy revealed that humate contributed to increase the copper content of the test sheets. The antimicrobial impact of test sheets on various fungi (Penicillium expansum,Wallemia sebi, andAspergillus brasiliensis) and bacteria (generaMicrococcus,Enterococcus,Bacillus,Salmonella,Staphylococcus,Listeria genera) was tested using a modified agar diffusion ‐based assay. On the basis of the disc diffusion results, the sheets effectively inhibited all the tested fungi and Gram‐positive bacteria. The highest antimicrobial effect was exhibited by the copper‐containing test sheet with 1:0.1 and 1:0.25 cellulose:humate weight ratio. Deterioration test with blackberries demonstrated the shelf life extending effect of the sheets.
Source: Packaging Technology and Science - Category: Food Science Authors: Tags: RESEARCH ARTICLE Source Type: research