Canned tuna, a key canned seafood product, primarily uses albacore and yellowfin tuna as raw materials and is processed into a variety of varieties, including original tuna, spiced tuna, oil-preserved tuna, vegetable tuna, and tuna in tomato sauce.
But you may not know that tuna muscle contains a high amount of sulfur protein, which easily reacts chemically with packaging materials, requiring special packaging protection. This is why canned tuna is commonly packaged in tinplate cans with a dual-purpose sulfur and acid-resistant coating.
Tinplate, also known as tinplate, is a cold-rolled steel sheet coated on both sides with an extremely thin layer of tin. It perfectly combines the strength and formability of steel with the corrosion resistance and solderability of tin, resulting in corrosion resistance, non-toxicity, high strength, and excellent ductility.
Tin's chemical stability makes it resistant to corrosion and effectively prevents rust from forming on the iron sheet. This protective layer of tin allows tinplate cans to remain rust-free for over a decade when properly protected.
However, once the tin layer is damaged, the iron sheet will quickly rust. This is why it is important to avoid damaging the tin layer when using tinplate cans and to protect them from moisture and heat.
Tinplate cans provide multiple protections for tuna:
Excellent Sealing: Tinplate cans effectively isolate oxygen and moisture, significantly extending the shelf life and preventing spoilage.
Perfect Light Protection: Light accelerates oxidation and nutrient loss in food, while tinplate cans completely block light, preserving the quality of the tuna.
Strong Corrosion Resistance: Tuna contains a high content of sulfur proteins, which poses a risk of corrosion. Tinplate cans' sulfur and acid resistance perfectly address this challenge.
High-strength protection: Modern tinplate cans can withstand strengths exceeding 600 MPa, equivalent to a force of 6 tons per square centimeter, significantly stronger than ordinary steel.
Tuna is known as the "chicken of the sea," and the International Nutrition Organization recommends it as one of the world's three most nutritious fish. Its tender meat is low in fat and calories, rich in high-quality protein and numerous nutrients, including DHA, EPA, omega-3 fatty acids, taurine, potassium, and vitamin B12.
DHA plays an important role in brain development and memory enhancement, while EPA inhibits cholesterol levels, prevents arteriosclerosis, and plays a special role in the prevention and treatment of cardiovascular and cerebrovascular diseases.
These precious nutrients are easily degraded by oxygen, light, and temperature. The light-proof, oxygen-isolating, and airtight properties of tinplate cans maximize the preservation of tuna's nutrients and flavor, ensuring that every bite is as close to its original canned state as possible.
You want your food to stay safe and fresh until you open it. Tin cans give you that protection. The strong barrier of tinplate keeps out oxygen, moisture, and light. This helps prevent spoilage and keeps harmful bacteria from growing inside the can. The non-porous surface of tinplate makes it hard for bacteria to get in or multiply. When you buy tuna cans, you get food that stays safe for years without needing extra preservatives.
The canning process uses high heat to kill all bacteria and pathogens, including tough spores like those of Clostridium botulinum. After sealing, the food inside tuna cans cannot get contaminated. You can store canned tuna at room temperature for two to five years. This long shelf life comes from the way tin cans deactivate enzymes and microorganisms during canning. Many experts say that canned food is safer than other preserved foods because the process stops the growth of germs that cause illness.
You need packaging that can handle shipping, stacking, and storage. Tin cans offer strength and reliability. The sturdy metal resists crushing and breaking, so your tuna cans arrive safely whether you buy them at a local store or order them from another country. Tinplate cans support global trade. In 2024, companies used over 20 billion steel cans worldwide for tuna packaging. These cans travel to more than 119 countries, including major importers like the United States, Costa Rica, and Vietnam.
Tin cans make it easy for manufacturers to ship tuna across oceans and continents. The tough exterior protects the food inside from bumps and drops during transport. You can stack tuna cans in your pantry without worrying about leaks or spills. This durability means you get high-quality tuna, no matter where you live.
The production process of tinplate cans is constantly innovating. Shougang Jingtang, for example, uses a complete three-step desulfurization process to reduce the weight ratio of impurity elements such as phosphorus and sulfur to less than 5 parts per million, while harmful elements such as arsenic and lead are controlled to 1 part per million.
This equates to the total weight of these harmful elements in a ton of molten steel being less than that of a grain of rice.
Modern tinplate cans are also moving towards lightweighting and environmental friendliness. Through a secondary cold rolling process, the thickness can be reduced by 10% while still meeting the product's strength and hardness requirements.
This means that one ton of steel plate can produce approximately 2,000 more standard cans than before, significantly reducing resource consumption.
With growing environmental awareness, the tinplate packaging container market is also moving towards more environmentally friendly methods. Foreign companies have developed a safer and more environmentally friendly methanesulfonic acid system (MSA) to replace the phenolsulfonic acid system (PSA) for high-speed tin plating.
You want food that is easy to store and take with you. Tinplate cans make this possible. They keep tuna fresh and safe by blocking air and bacteria. You can stack cans in your pantry or pack them in your bag for a trip. Unlike glass jars, cans do not break easily. Unlike plastic pouches, cans protect food from crushing and spoilage.
Tip: You can store canned tuna for years without worrying about it going bad. This makes meal planning and emergency storage much easier.
You might wonder why tinplate cans are a smart choice for the planet and your wallet. Tinplate cans are highly recyclable. Over 95% of tinplate food cans, including tuna cans, get recycled worldwide. In the EU, 82% of all tinplate packaging is recycled. This rate is much higher than many other packaging materials.
Tinplate cans use low-carbon steel and tin, making them strong and light. You can recycle them many times without losing quality. Glass containers are heavier and need more energy to make and move. Plastic can be less eco-friendly if not recycled properly.
Life cycle studies show that making and moving tinplate cans does impact the environment, but their high recycling rate helps reduce waste. Many tuna cans also carry certifications like Dolphin Safe or Marine Stewardship Council, showing a commitment to sustainability.
Now that you understand the advantages of tinplate cans, how do you choose high-quality canned tuna from the vast selection? Here are a few tips:
Check the packaging: The packaging should be sealed and undamaged. Avoid cans that appear bulging or dented.
Check the label: The label should contain complete information, including the name, net weight, manufacturer, address, contact information, ingredients, nutritional information, production date, and expiration date.
Choose products with a high solids content: This means the can contains more actual fish.
Choose products with fewer food additives: Minimize unnecessary additive intake.
Check the texture: High-quality canned tuna should have a firm, tender texture, be free of blood clots, hard bones, and impurities.
You get better protection from tinplate. Tin cans block air and light. This keeps tuna fresh and safe for a long time.
You benefit from the airtight seal. Tin cans stop bacteria and moisture. This lets you keep tuna cans in your pantry for years.
You receive tuna cans in good condition. Tin cans resist crushing and damage. This makes shipping safe and reliable.
