Technological watch

Evaluation of food packaging paper for microbial load and storage effect on the microbial activity of paper

Paper is safer than plastics and metals for packaging of food. However, presence of cellulose in pulp and paper makes the paper?based packaging material favourable for microbial growth. Checking the growth of microorganisms and setting the microbial limit are crucial steps to ensure food safety. This study pinpoints the correct approach to evaluate the microbial load in paper and board and to test the storage effect on microbial load.Paper and paper board are an ideal choice of packaging material due to their biodegradability. They are safer than commonly used plastic packaging materials. But due to the presence of carbon sources like cellulose and starch in paper, various pathogenic and non?pathogenic microbes can grow well in them. The migration of microorganisms or their spores from paper to food may cause serious health hazards. Taking consumer concerns into picture, the regulatory authorities should come up for food packaging standards with regard to microbial limits of paper used in food packaging. This study pinpoints the correct approach, that is, the disintegration method in comparison to direct plating in evaluating the microbial load of 14 different samples of paper by demonstrating the limitations of methods that were eliminated. The samples were also tested for storage effect on microbial load and found to have significant reduction in bacterial load during storage at 4°C, but for fungi, it remained nearly unchanged. Further identification of predominating microbes was performed, and conclusions have been drawn on the presence of harmful and harmless species in the samples of paper. It was found that all the identified fungi are mycotoxin producing and may lead to illness of the consumer. Unlike fungi, dominating bacterial strains were found to be non?harmful for food packaging purposes and ultimately for human use. Overall, there is an immediate need to set microbial limit standards in food packaging paper and paperboard in order to supply safe and hygiene food to consumers.

Publication date: 13/04/2022

Packaging Technology and Science


This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 837761.