Retort packaging technology prolongs the food product development shelf life and prevents spoilage. During processing the volatile and non-volatile compounds are being release that affect the metal coating. This can weaken the protective coating, making it less effective at stopping corrosion inside the metal cans over time. So, controlling how much these heats driven breakdowns happen is vital to keep the cans strong and safe on a long run.
Characterization of volatile and non-volatile compounds in retort processed green beans packaged in polymer coated metallic cans
Retort packaging technology prolongs the food product development shelf life and prevents spoilage. During processing the volatile and non-volatile compounds are being release that affect the metal coating. This can weaken the protective coating, making it less effective at stopping corrosion inside the metal cans over time. So, controlling how much these heats driven breakdowns happen is vital to keep the cans strong and safe on a long run.
Why are metal can preferred for packaging?
Metal cans are preferred due to their superior preservation and protection properties. They provide barrier against air, light, and moisture that cause food spoilage thus preserving the freshness, taste, and nutritional quality for long periods.
Advantages | Disadvantages |
Withstand high temperatures and pressure | Metal cans are heavier than flexible packaging |
100% recyclable without quality loss | They are prone to corrosion |
Offers longer shelf life without refrigeration | It does not offer visibility |
Metal coating is a protective layer applied either inside or outside surface of the metal can. The purpose is to prevent the metal from reacting with food or beverage, that leads to spoilage. The table below presents the coating type, product description, its role, advantages and disadvantages. [1]
Coating Type | Description | Role/function | Advantages | Disadvantages |
Epoxy coating | Thermoset polymer coating | Corrosion resistance | Excellent adhesion, heat resistance | Inclusion of BPA |
Polyester coating | Thermoplastic polymer coating | Transparency, durability | Acid and heat resistance | Less flexible than epoxy |
Acrylic coating | Flexible polymer coating | Protection against acidic foods | Acid resistance, flexible | May have lower chemical resistance |
Oleoresin coating | Natural oil-based polymer | Corrosion resistance, BPA free alternative | Safe natural origin | Lower adhesion |
Phenolic coating | Resin based coating | High heat resistance | Thermal stability | Brittle, prone to cracking |
Scientific Study
The study by [Elliot Dhuey et al., 2025] emphasis the effect of green beans, chlorophyll and methyl cysteine on two polymer coatings (Corrosion resistant polymer) including Polyethylene terephthalate (PET) and Polyester applied to metallic cans. After filling, sealing and retort processing, cans were stored at 40OC for 90 days. Volatile and non-volatile compound sorption by coating was analysed using selected-ion flow-tube mass spectrometry (SIFT-MS), gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS). It is found that thermal degradation of methyl cysteine and chlorophyll forms reactive sulphur and nitrogen containing compounds. Dimethyl disulphide levels increased up to 5 folds and 3.5-fold in PET and polyester coatings respectively. [3]
Why green beans have been selected for research studies?
Green beans serve as an ideal model in nutritional product development and food technology innovation studies because they:
- It is widely used in the canning industry as a common vegetable processed in metal cans
- They serve as a representative vegetable to study the effects of retort processing, which is a thermal sterilization method to prevent food spoilage and extend food product shelf life.
- It can lead to significant changes including colour, texture loss, chemical compound alterations.
- Studying green beans helps understand how packaging materials such as metallic cans coated with corrosion resistant polymers, influence the preservation of quality and safety during and after thermal processing
- Green beans have noticeable volatile and non-volatile compounds that affect flavour, nutrition and overall consumer acceptance, making them a good model to evaluate the compositional changes imparted by retort and packaging.
What technology is used in volatile and non-volatile compounds characterization
- Volatile compounds in the internal coatings of cans were measured using SIFT-MS following the retort treatment of green beans at 125°C.
- Unknown compounds from the green beans that reacted with the can coatings were identified and measured using GC–MS. The benefit of GC–MS is its ability to analyse compounds with melting points above 100°C, which is an appropriate characteristic for a product that underwent a retort process at a temperature of 125°C.
- Due to higher melting points (>250°C), LC–MS was used to analyse higher molecular weight compounds.
How retort packaging improves food product shelf life?
- It improves food product’s shelf life by sterilizing food that is sealed inside flexible pouches using high temperature and high-pressure steam. This effectively kills bacteria and microorganisms that is responsible for food spoilage.
- The product can maintain its freshness for 12 to 36 months at ambient temperature without refrigeration. The retort packaging materials, typically multilayer laminates of plastics and aluminium foil, can withstand the sterilization temperatures (~116-130 °C) and seal to an airtight barrier that prevents contamination and gas permeation, providing greater preservation of freshness, flavor, nutrients and texture than conventional canning. [4]
Major retort packaging manufacturers
- Amcor – A global leader in consumer packaging solutions
- Winpak – A company that provides flexible and rigid packaging for a variety of industries
- Mondi – Known for environmentally responsible retort packaging production
Key Brands and Innovators
- Otsuka Foods – They launched the world’s first commercial retort pouch.
- Tetra Pak – A leader in developing recyclable, environmentally friendly packaging solutions
Conclusion
Retortable packaging represents an advanced food product development strategy, combining thermal sterilization with protective coatings to extend shelf life while safeguarding safety and sensory quality. Depending on the food matrix, pH, and sulfur- or nitrogen-containing compounds, thermal treatment can cause chemical interactions with the metal surface. Polymer coatings act as barriers, minimizing these interactions and maintaining product integrity.
At our Food Research Lab, we integrate food technology and innovation with food retort processing technology and nutritional product development to optimize food–package interactions. We focus on nutrient stability, polymer performance during thermal processing, and food product formulation packaging, offering scientifically tailored solutions that enhance shelf life, nutrition, and safety.
Partner with Food Research Lab to elevate the quality, safety, and longevity of your food products through innovative food product development and packaging solutions. Start your journey in food technology and innovation today.
Let’s create something Innovative and Delicious together
Food Research Lab strives for excellence in new Food, Beverage and Nutraceutical Product Research and Development by offering cutting edge scientific analysis and expertise.
