Today’s consumer is more aware than ever of plastics' impact on our planet. Commercial food producers and retailers have heard these demands and have sought ways to reduce the use of plastic food packaging.
Every food product has a countdown clock: from the moment it is processed, factors like oxygen, heat, moisture, microbes, and physical damage risk diminishing its quality and freshness.
The right packaging strategy plays a critical role in slowing that process.
In this article, we'll explore the science behind shelf life, why plastic remains one of the most effective packaging materials available, and how packaging innovations are helping food products stay fresh longer.
Why Is Food Packaged and How Does It Impact Shelf Life?
To understand shelf life, it helps to start with a basic question: why is food packaged in the first place?
In short, food packaging protects products from the conditions that cause them to deteriorate. Throughout storage, transportation, and display, food is exposed to a range of factors that can affect its quality, safety, freshness, and shelf appeal, including:
- Oxygen exposure
- Moisture gain or loss
- Microbial contamination
- Temperature fluctuations
- Light exposure
- Physical damage during handling and transport
These same factors are also some of the primary drivers of shelf life. The longer food remains protected from these external influences, the longer it can maintain its intended taste, texture, appearance, and safety.
That’s why choosing the right packaging is a critical part of food preservation. Different packaging materials provide different levels of protection against the conditions that accelerate spoilage, helping food products remain fresh from production through purchase.
Scientific Benefits of Plastic Packaging for Food Products
Plastic offers distinct benefits for shelf-life when used in food packaging design. Besides being lightweight and strong, plastic’s inherent qualities help directly address some of the core risks to shelf life outlined above.
- Air-tight: Whether using a formed plastic lid or film seal, plastic food packaging can be designed to keep air out, keeping food fresh longer.
- Water-tight: In addition to keeping air out, innovative packaging designs can protect food from outside liquids and keep food locked tightly inside to prevent leaks.
- Extends shelf life: Plastic packaging locks in prepared foods and can extend the shelf life of many foods, reducing food waste. In the case of produce, plastic prevents spoilage due to ethylene gasses and keeps ethylene-emitting fruits and vegetables from spoiling other produce.
- Malleable: The chemical formula of different plastics impacts its malleability and strength, making it a versatile option depending on your application. For example, plastic containers can be designed to include thermoformed sections to keep different foods separate.
- Non-permeable: Permeability refers to the rate at which molecules (such as oxygen) can pass through a material. Packaging requires a low permeability rate for oxygen and water to keep food fresh.
- Tamper-resistant: Food safety is a concern for consumers. Plastic packaging for food is not only durable for keeping food intact, but it also provides a tamper-resistant barrier, protecting food from human interference. Modern plastic packaging designs include a variety of sealing mechanisms, from tear-away seals to film sealing, that help consumers feel confident their food is sealed and safe.
Common Food Packaging to Extend Shelf Life
Food packaging is often designed to directly mitigate common risks to shelf life (especially for the highly popular category of fresh grab-and-go foods). Some of the most common plastic food packaging technologies used to extend shelf life include:
- Modified atmosphere packaging (MAP): This technique replaces the oxygen inside a sealed package with protective gases such as nitrogen or carbon dioxide. By changing the atmosphere around the food, MAP helps slow microbial growth and reduce lipid oxidation in products like meats, cheeses, and baked goods.
- Vacuum packaging: Removes air from the package before sealing. With less oxygen present, vacuum packaging helps inhibit aerobic bacteria and mold growth while also helping prevent freezer burn during frozen storage.
- Active and intelligent packaging: Uses integrated features such as oxygen scavengers, moisture absorbers, or antimicrobial films to actively preserve freshness inside the package. Intelligent packaging can also include indicators that track conditions such as temperature changes over time.
Plastic Food Packaging Materials and Shelf Life
There are various plastic containers commercial food producers can use to package and protect their products. Here are a few of the most common commercial applications for plastic food containers:
- #1 PET: This type of plastic is used for grab-and-go food containers, cookie trays, bottles for condiments, nut butters, and cooking oils. It is typically one of the most transparent plastics, great for showing off the food inside. By repelling microorganisms, this type of plastic keeps food fresh longer. It’s also durable and is resistant to corroding, providing a superior barrier against contaminants and moisture.
- #2 HDPE: This type of plastic has less clarity and is often used for milk bottles, ice cream containers, and plastic bags. Because it is resistant to moisture, it’s often used for storing liquids. It’s also heat resistant, making it dishwasher safe. HDPE is prone to cracking, is flammable, and does not bond well with other food-grade plastics, which could be a factor in some applications.
- #5 PP (polypropylene): This plastic has a higher melting point, making it great for storing microwaveable dishes, yogurt, and ice cream. However, it is still flammable and is susceptible to UV degradation and oxidation. In addition, PP can be clear, opaque or come in a wide variety of colors, giving commercial food producers the opportunity to stand out on the shelf.
Shelf Life, Sustainability, and Smarter Plastic Packaging
The shelf-life benefits of plastic packaging can work alongside sustainability goals. Post-consumer recycled plastic, or PCR, can help reduce reliance on virgin materials without moving away from the performance advantages that make plastic effective for food packaging.
PET is a great example. Virgin PET can be recycled into rPET and used in other products after it is collected, sorted, cleaned, and processed. Lacerta’s ReCERTA™ program guarantees an average of at least 10% PCR content across all PET products, with custom blends available upon request.
Seal N’ Flip™ shows how these priorities can come together in a package designed for fresh food performance. The format uses a bottom-facing film seal, allowing retailers and food brands to plate food, seal the package, and flip it for a premium, product-forward shelf presentation. Designed for grab-and-go items such as sandwiches, wraps, hoagies, snacks, and prepared offerings, the format helps showcase food clearly while maintaining functional benefits such as tamper resistance, leak protection, and compatibility with standard packaging line equipment.
The design also supports material and cost efficiency. Compared with similar-sized plastic clamshell containers, Seal N’ Flip uses up to 50% less plastic and offers up to 25% potential savings in material cost. For those reasons, this product line provides a practical example of how packaging design can support shelf-life performance, recycled-content goals, material reduction, and cost control.
How Your Packaging Manufacturer Can Help
Design is a key component of any packaging. When working with an experienced vendor and innovative food design team, you can extend the shelf life of your products and boost shelf appeal. At Lacerta, we have 30 years of expertise in food packaging to help your products shine on the shelf.
We’d love to show you what we do best. For a closer look at our products, request a sample.
