Exploring chitosan-plant extract bilayer coatings : advancements in active food packaging via polypropylene modification

Kaloper, Saša (author), Plohl, Olivija (author), Smole Možina, Sonja (author), Vesel, Alenka (author), Šimat, Vida (author), Fras Zemljič, Lidija (author)

UV-ozone activated polypropylene (PP) food films were subjected to a novel bilayer coating process involving primary or quaternary chitosan (CH/QCH) as the first layer and natural extracts from juniper needles (Juniperus oxycedrus; JUN) or blackberry leaves (Rubus fruticosus; BBL) as the second layer. This innovative approach aims to redefine active packaging (AP) development. Through a detailed analysis by surface characterization and bioactivity assessments (i.e., antioxidant and antimicrobial functionalities), we evaluated different coating combinations. Furthermore, we investigated the stability and barrier characteristics inherent in these coatings. The confirmed deposition, coupled with a comprehensive characterization of their composition and morphology, underscored the efficacy of the coatings. Our investigation included wettability assessment via contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), which revealed substantial enhancements in surface concentrations of elements and functional groups of CH, QCH, JUN, and BBL. Scanning electron microscopy (SEM) unveiled the coatings' heterogeneity, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) and CA profiling showed moderately compact bilayers on PP, providing active species on the hydrophilic surface, respectively. The coatings significantly reduced the oxygen permeability. Additionally, single-layer depositions of CH and QCH remained below the overall migration limit (OML). Remarkably, the coatings exhibited robust antioxidative properties due to plant extracts and exceptional antimicrobial activity against S. aureus, attributed to QCH. These findings underscore the pivotal role of film surface properties in governing bioactive characteristics and offer a promising pathway for enhancing food packaging functionality.

• Language: English
• Keywords: chitosan, plant extracts, polypropylene, active packaging, surface characterization, bioactivity
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 14 str.
• Numbering: Vol. 270, pt. 2, art. 132308
• PID: 20.500.12556/RUL-158207
• UDC: 577:543.2/.9
• ISSN on article: 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.132308
• COBISS.SI-ID: 196837891
• Publication date in RUL: 29.05.2024

Record is a part of a journal

• Title: International journal of biological macromolecules
• Shortened title: Int. j. biol. macromol.
• Publisher: Elsevier
• ISSN: 1879-0003
• COBISS.SI-ID: 107163139

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: hitozan, rastlinski izvlečki, polipropilen, aktivna embalaža, karakterizacija površin, bioaktivnost