Improvement in liquid absorption of open‐cell polymeric foam by plasma treatment for food packaging applications

Alaa Alaizoki,Craig Hardwick,James Mcgettrick,Christopher Phillips,David Parker,Davide Deganello

doi:10.1002/app.52015

Alaa Alaizoki, Craig Hardwick + Show 4 more

Open Access

https://doi.org/10.1002/app.52015

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Abstract

AbstractFree‐moving meat exudate in plastic packaging is perceived as unhygienic and unattractive by consumers. It facilitates the deterioration of meat quality and safety, increasing meat waste and loss. This work discusses an innovative approach in scavenging meat exudate within commercial plastic packaging. This involves improving the liquid absorption capabilities of open‐cell polystyrene (PS) foam through the application of oxygen plasma treatment rather than chemical wetting agents. The excited plasma species diffuse into the porous foam structure introducing polar oxygen groups onto the pore walls and improves their surface hydrophilicity. Hence, the foam pores, with enhanced wettability towards water‐based liquids, are proposed to have a larger sucking capillary pressure thus increasing the absorption capacity of the porous PS foam. The specific liquid absorption capacity of PS foam sheets (thickness: 5 mm) increased from 1.09 g g−1 (grams of exudate simulant liquid absorbed per gram of PS foam) to 8.78 g g−1 as a result of plasma treatment; an eightfold increase in liquid capacity (g g−1) that persisted even 60 days post treatment. This study demonstrates the practicality of using plasma treatment as a non‐chemical and efficient technology in scavenging meat and food exudates in plastic packaging.

Highlights

Food freshness, safety, and shelf life are crucially dependent on food packaging
The high porosity and open-cell content of the PS foam are among the crucial structural parameters, which determine the potential for the foam samples to uptake significant liquid quantities
This was reflected in the large gaseous space within the foam matrix as the porosity represents the volume of gaseous cells to the sample volume.[19]

Summary

| INTRODUCTION

Safety, and shelf life are crucially dependent on food packaging. The packaging provides a protection to the contained food from various physical and chemical contaminants, and it inhibits the proliferation of spoilage and pathogenic bacteria.[1,2,3] The development of food packaging functionalities is gaining more interest in light of growing demand for safer, healthier and longer shelf-life food.[3]. The surface wettability and chemical composition of the aged foam samples were characterized by WCA and XPS techniques respectively.[44] The absorption capacity (R) was measured for the foam samples with BSA 8wt% (γ: 52.0 mN mÀ1). The surface wettability, chemical composition, and absorption capacity were determined with three repeats per measurement in different durations over 60 days.[43] For practicality of using PS foam as a soak-away in food packaging, the liquid absorption capacity was estimated in kilograms of absorbed liquid per cubic meter of the PS foam

| RESULTS

Findings

| DISCUSSION

| CONCLUSION