Antimicrobial paper coatings containing microencapsulated Cymbopogon citratus oil

Šumiga, Boštjan (author), Šumiga, Barbara (author), Ravnjak, David (author), Boh Podgornik, Bojana (author)

Essential oils are environmentally friendly candidates for antimicrobial smart packaging systems. Encapsulation is needed to reduce their volatility and achieve controlled release. Within this study, the essential oil of Cymbopogon citratus (citronella oil) was microencapsulated and applied in pressure-sensitive antimicrobial functional coatings on papers for secondary packaging. Two microencapsulation methods were used: complex coacervation of gelatine with carboxymethylcellulose or with gum arabic, and in situ polymerization of melamine-formaldehyde prepolymers with a polyacrylic acid modifier. Minimum inhibitory concentrations of citronella oil microcapsules were determined for Bacillus subtilis (B. subtilis), Escherichia coli (B. subtilis), Pseudomonas aeruginosa (P. aeruginosa) and Saccharomyces cerevisiae (S. cerevisiae). Microcapsule suspensions were coated on papers for flexible packaging, 2 and 30 g/m$^2$, and mechanically activated in the weight pulling test. A novel method on agar plates in sealed Petri dishes was developed to evaluate the antimicrobial activity of released citronella vapours on E. coli and S. cerevisiae. The results showed that both microencapsulation methods were successful and resulted in a container type single-core microcapsules. In situ microcapsule suspensions had better paper coating properties and were selected for industrial settings. The antimicrobial activity of 2 g/m$^2$ coatings was not detected; however, the antimicrobial activity of 30 g/m$^2$ partially activated coated papers was confirmed. The product enabled a prolonged use with the gradual release of citronella oil at multiple exposures of functional papers to pressure, e.g., by a human hand during product handling.

• Language: English
• Keywords: antimicrobial paper, Cymbopogon citratus, essential oil, microcapsules, coacervation, in situ polymerization, coating, morphology, antimicrobial tests
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2019
• Number of pages: 21 str.
• Numbering: Vol. 9, iss. 8, art. 470
• PID: 20.500.12556/RUL-132846
• UDC: 54
• ISSN on article: 2079-6412
• DOI: 10.3390/coatings9080470
• COBISS.SI-ID: 1498462
• Publication date in RUL: 05.11.2021

Record is a part of a journal

• Title: Coatings
• Shortened title: Coatings
• Publisher: MDPI AG
• ISSN: 2079-6412
• COBISS.SI-ID: 523035673

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.08.2019

Projects

• Funder: Other - Other funder or multiple funders
• Funding programme: Republic of Slovenia, Ministry of Education, Science and Sport
• Project number: OP20.00365
• Name: Potential of biomass for development of advanced materials and bio-based products
• Acronym: Cel.Cycle

• Funder: EC - European Commission
• Funding programme: European Regional Development Fund
• Name: Potential of biomass for development of advanced materials and bio-based products
• Acronym: Cel.Cycle