The role of packaging in maintaining food quality

Exploring the science behind packaging's role in extending shelf life, preserving nutritional value, and preventing food spoilage. By Luke Martin.

Packaging acts as a guardian, regulating elements within an optimal range for specific food categories. Credit: Drazen Zigic via Shutterstock

The optimal packaging choice depends on the specific food category. Credit: Drazen Zigic via Shutterstock. 

In today's competitive food industry, ensuring product quality from farm to table is paramount. While taste and branding undoubtedly influence consumer decisions, packaging also plays a critical role.  

Effective packaging extends shelf life, minimises spoilage, and safeguards food safety, ultimately contributing to a brand's success.  

This article explores the scientific principles behind packaging's impact on food quality and examines the evolving landscape of packaging materials and technologies. 

The science of food preservation 

Food quality is a delicate balance of factors: moisture content, oxygen levels, light exposure, and temperature. Packaging acts as a guardian, regulating these elements within an optimal range for specific food categories. 

Packaging materials play a crucial role in moisture management. Waxed cardboard, for example, excels at keeping moisture out, ideal for preserving dry goods like cereals. Conversely, some plastics allow controlled respiration for fruits and vegetables, preventing them from drying out and extending shelf life. 

Oxygen exposure accelerates spoilage and oxidation in certain foods. Metal cans and some plastics create a near-oxygen-free environment, ideal for products susceptible to oxidation, like oils and nuts. Modified Atmosphere Packaging (MAP) replaces air with a controlled gas mixture to further extend shelf life by inhibiting bacterial growth. 

Exposure to light can degrade vitamins, change colour, and trigger unwanted chemical reactions. Opaque or light-filtering packaging protects light-sensitive foods like milk and yogurt, ensuring they retain their freshness and nutritional value. 

Material selection for optimal quality 

The type of packaging material significantly impacts food quality. 

Glass offers excellent light barrier properties for light-sensitive products but can be heavy and fragile, limiting its use for some applications. 

Metal cans provide a superior oxygen barrier, ideal for long shelf life but not suitable for all foods and can limit product visibility. 

“The hermetic seal provided by metal cans offers robust protection against oxygen and light exposure, which can degrade food quality over time,” says Rimas Geiga. Medical Doctor, Registered Dietician Nutritionist.  

“The rapid canning of food preserves nutritional content and reduces vitamin loss, enhancing the end product for the consumer. For instance, canned tomatoes hold up to four times the amount of lycopene as found in freshly prepared tomatoes. Canned foods also enjoy exceptionally long shelf lives, typically ranging between 1 to 5 years,” states Jenny Wassenaar, Chief Sustainability Officer at Trivium Packaging. 

“Canned food allows for year-round availability, and by requiring no refrigeration, canning is among the most cost-effective and environmentally responsible ways to get food safely to where it is needed,” added Wassenaar. 

Plastic is versatile and lightweight, but some types allow oxygen permeability. Choosing the right plastic type is crucial for specific food categories. High-density polyethylene (HDPE) offers good moisture resistance, making it suitable for cereals, while low-density polyethylene (LDPE) is more flexible and often used for produce bags. 

While paper and cardboard are good sustainable options for dry goods, they require careful moisture management to prevent spoilage. Wax or laminate coatings can be applied to improve moisture resistance. 

“Their porous nature allows for airflow, preventing moisture buildup and extending shelf life. Moreover, their recyclability aligns with the growing consumer demand for environmentally conscious packaging choices,” says Geiga. 

Multi-layer packaging offers targeted protection. For instance, plastic pouches with aluminium foil can extend shelf life for certain products by providing a superior oxygen barrier and light protection. 

“By combining layers of plastic, paper, aluminium, and other materials, multi-layer packaging achieves superior protection against oxygen, moisture, light, and odours, making it suitable for a wide range of perishable and processed foods,” adds Geiga. 

Food category considerations

The optimal packaging choice depends on the specific food category. 

For fresh produce, maintaining freshness and minimising spoilage are paramount. Packaging with controlled ventilation allows produce to breathe, preventing buildup of moisture and carbon dioxide. Anti-microbial coatings are also being explored to further extend shelf life. 

Preserving texture and freshness in bakery goods is key. Breathable packaging prevents moisture build-up that can lead to sogginess, while clear windows maintain a bakery-fresh look for consumer appeal. 

Light sensitivity and potential for bacterial growth require special attention when it comes to dairy products. Opaque plastic containers with tamper-evident seals ensure both product quality and safety by protecting from light and preventing contamination. 

Meat and seafood products are highly perishable. Vacuum sealing removes air, which inhibits bacterial growth. Modified atmosphere packaging with a controlled gas mixture further extends shelf life and maintains freshness. 

The future of food packaging 

Innovation in packaging continues to push boundaries.  

Smart packaging such as the use of sensors embedded within packaging can monitor factors like temperature and internal gas composition, providing real-time data on food quality and spoilage risk. This information can be used to optimise supply chain management, minimise food waste, and improve consumer safety. 

“Smart packaging equipped with sensors and IoT capabilities enables real-time monitoring of food conditions throughout the supply chain, empowering consumers to make informed decisions about product freshness and safety,” says Geiga. 

Active packaging incorporates elements into the packaging itself that actively interact with the food. For example, oxygen absorbers can slow down spoilage in certain products, while antimicrobial films can inhibit bacterial growth. 

Furthermore, the development of bio-based and biodegradable materials holds immense promise for the future of packaging. These eco-friendly alternatives can offer comparable performance to traditional materials while minimising environmental impact. 

Packaging is no longer an afterthought in the food industry. It's a strategic tool used to ensure food quality, minimise waste, and enhance consumer experience.  

By understanding the science behind packaging's impact and staying abreast of evolving trends and technologies, food producers and packaging manufacturers can work together to create solutions that optimise food quality, promote brand value, and contribute to a more sustainable future.