Super-Critical Fluid Extraction (SFE) with CO2 as decontamination step for recycling polyethylenes for food contact

Jiménez Estremera, Carlos ; Lóbez, Silvia (Universidad de Zaragoza) ; Belgharbi, Fallah (Universidad de Zaragoza) ; Mainar, Ana M. (Universidad de Zaragoza) ; Nerín, Cristina (Universidad de Zaragoza) ; Vera, Paula (Universidad de Zaragoza)

Resumen: The recycling of polyolefins remains a significant challenge in the context of food contact materials (FCM) due to contamination by both volatile and non-volatile compounds. Supercritical Fluid Extraction (SFE) with carbon dioxide (CO2) has emerged as a promising technology for being included as an efficient step of decontamination or postconsumer polyolefins, ensuring their safety and quality for food contact applications. This study evaluates the capability of SFE to decontaminate postconsumer polyolefin-based materials, including multilayer polyethylene (PE) and polyamide 6,6 (PA-6,6) plastic bags, high density polyethylene (HDPE) containers, and post-consumer HDPE packaging, all previously in contact with food. A non-targeted analytical approach was applied using headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and ultrahigh performance liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer (UPLC-QTOF-MS) to detect and semi-quantify contaminants before and after SFE treatment and a total of 121 compounds were detected in this non-target analysis. Among them, several common plastic additives and various food-derivative compounds, degradation or oxidation products of these additives were found. The results demonstrated up to 99 % decontamination efficiency for volatile compounds and 75 % for non-volatiles, based on the total concentration of compounds before and after the SFE process. These efficiencies highlight the potential of SFE as a critical step for enhancing the quality of recycled polyolefins. The study underscores the role of SFE in advancing the recyclability of polyolefins within the framework of a circular economy. By addressing contamination challenges—both chemical and structural—and enabling the safe reuse of materials in food contact applications, this technology contributes to reducing plastic waste and promoting sustainable material management.
Graphical Abstract

Idioma: Inglés

DOI: 10.1016/j.fpsl.2025.101682

Año: 2026

Publicado en: Food Packaging and Shelf Life 53 (2026), 101682 [11 pp.]
ISSN: 2214-2894

Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2021-128089OB-I00

Tipo y forma: Article (Published version)

Área (Departamento): Área Química Analítica (Dpto. Química Analítica)
Área (Departamento): Área Química Física (Dpto. Química Física)
Área (Departamento): Proy. investigación HVA (Dpto. Química Analítica)