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From PET to Carton: Rethinking Strawberry Packaging

  • Writer: Ifat Hammer
    Ifat Hammer
  • Nov 19
  • 4 min read

Updated: 4 hours ago

How we improve compliance with upcoming packaging regulations, meets consumer expectations for sustainability and help retailers reduce food waste


Ifat Hammer, CTO & Co-founder


For years, strawberries have been packed in rigid PET clamshells—transparent, protective, and convenient. These containers were designed to minimize damage and maintain freshness during transport.


But as sustainability becomes a global priority, the fresh produce industry faces mounting pressure to reduce plastic waste. Retailers and growers are now exploring alternatives, and Top Seal packaging—where a thin film replaces the clamshell lid—has emerged as a promising solution. This approach significantly cuts plastic use while maintaining visibility and branding.


The next step in this evolution is carton trays with Top Seal, offering even greater environmental benefits. Cardboard is recyclable, lightweight, and aligns with upcoming regulations banning single-use plastics. However, this transition introduces a new challenge: carton absorbs moisture, which can compromise product integrity and shorten Shelf-Life. Removing the cover isn’t an option—Top Seal is essential for protection and logistics. So, how can we make carton packaging work for moisture-sensitive fruits like strawberries?



Strawberries in plastic container vs. carton container
Traditional PET Punnet Vs. Carton Punnet with Top Seal

The Trade-Off: Moisture Retention vs. Quality Risk

Strawberries require humidity to prevent dehydration, yet excessive humidity in a sealed pack can lead to condensation and visible decay. Research from physics-based modeling confirms this trade-off:

  • Open trays allow ventilation and reduce condensation, yet they cause excessive water loss—up to 7% in just 2.6 days, enough for consumers to reject the product (Tobler et al., 2024).

  • Covered trays reduce water loss, yet trapped humidity increases condensation risk. Mold-related losses often occur later in the chain, especially at retail when condensation persists (Shrivastava et al., 2023).


The studies show that condensation risk rises sharply when relative humidity exceeds 95%, and the time of wetness (TOW) inside sealed packs can reach 16 hours in poorly ventilated designs—conditions that accelerate decay (Shrivastava et al., 2023). Conversely, adding vents reduces TOW by up to 45%, but this comes at the cost of higher mass loss (Tobler et al., 2024). This is the classic trade-off: improving one parameter worsens the other.


Why Carton Matters for Sustainability

The environmental benefits of moving away from PET are clear. An independent Life Cycle Assessment (LCA) conducted by Lira Ltd quantified the impact of LiVA-enabled packaging compared to conventional clamshells:

  • Transitioning from PET clamshells to carton + LiVA achieved:

    • ~30% lower climate impact

    • ~47% reduction in freshwater ecotoxicity

    • 27–34% less fossil fuel and resource depletion

    • ~31% average reduction across all impact categories ([LCA Report, 2024]).


These gains go beyond packaging: they reduce waste, lower energy use, and minimize reliance on intensive refrigeration.



The diagram shows how two LiVA solutions used with carton improve various environmental parameters in comparison with commonly-used plastic packaging.
Percentage reduction in environmental impact of LiVA treated strawberries in cardboard as compared to current practices in clamshells (1 Kg consumed)

Making Carton Work: Shelf Life Innovation and Microbiome Advantage

The ventilated packaging studies highlight that design matters as much as material. Optimizing vent patterns and Total Opening Area (TOA) improves air flow and cooling, reducing condensation risk without excessive dehydration (Tobler et al., 2024). Digital twin simulations show that a TOA of 5.5–7% with well-distributed vents achieve the best balance between cooling efficiency and moisture control (Shrivastava et al., 2023).



Top Seal with LiVA

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TAO illustration: Balancing Airflow and Shelf Life: Ventilated Carton Packaging for Strawberries

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Carton punnet with apertures



LiVA builds on these insights by enabling carton packaging to maintain quality under real-world conditions. Beyond physical design, LiVA introduces a microbiome-friendly approach: its beneficial bacteria thrive on carton surfaces, creating a natural protective environment that supports fruit freshness.


This is not merely theoretical: our ongoing trials with mangoes confirm that LiVA performs exceptionally well in corrugated cardboard boxes, maintaining quality for up to 12–14 days in refrigeration compared to 5–7 days under conventional conditions (LCA Report, 2024).

The ability of these beneficial microbes to colonize carton effectively turns a potential weakness - moisture absorption - into an advantage, helping stabilize the microenvironment and reduce visible decay.



From Farm to Fork: A Cleaner, Smarter Supply Chain

The ability to combine carton and Top Seal without compromising product quality is game-changing. It supports compliance with upcoming packaging regulations, meets consumer expectations for sustainability, and helps retailers reduce food waste. As the studies in reference show, packaging design and supply chain conditions influence strawberry quality dramatically: ventilation, humidity control, and shelf-life strategies are critical to success (Tobler et al., 2024]; [Shrivastava et al., 2023).



To conclude: 

Transitioning from PET to carton is not only about changing materials but rethinking how we can maintain freshness. Supported by research and proven environmental benefits, LiVA enables this shift, helping the industry reduce plastic, cut waste, and deliver quality produce from farm to fork, for the benefit of satisfied consumers and the environment.





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