Canned fish producers know that the choice of oil, often olive or sunflower, can make or break their product’s quality and appeal. From preserving delicate fish flavors to ensuring a long shelf life, the packing oil is much more than a filler. Olive oil and sunflower oil are two of the most common mediums for canned seafood worldwide, each bringing distinct flavor profiles, preservation qualities, and sourcing considerations. In this article, we’ll explore why these oils matter: how oil selection for canning influences fish flavor and texture, the role of oils in fish flavor preservation and shelf stability, global sourcing trends for edible oils, and how oil price swings affect canned seafood producers.
Common oils used in canning
Olive oil and sunflower oil dominate as packing oils in the canned fish industry. Olive oil (especially in Mediterranean countries) is traditionally associated with premium canned fish, think of gourmet tuna or sardines in olive oil as a mark of quality. Sunflower oil, on the other hand, has a neutral taste and is typically more affordable, making it popular for mainstream products and large-scale canning. Soybean oil is another widespread choice, particularly in North America and parts of Asia, often labeled simply as “vegetable oil” on cans. Some products use generic “vegetable oil” blends (which might include soybean, rapeseed, or even palm oil) to cut costs. Each oil type has implications for flavor, nutrition, and cost:
- Olive Oil (Refined vs. Virgin): High-quality extra-virgin olive oil (EVOO) imparts a rich flavor and antioxidants, but it’s expensive and can be less stable at high heat. In practice, most “olive oil” packed fish uses refined olive oil or a blend of refined and virgin oils. Canneries often reserve pure EVOO for their top-shelf products (for example, specialty tuna fillets), since using 100% EVOO for everyday sardines would be cost-prohibitive. A survey of Spanish canned sardines found that out of 22 products, only one was packed in pure extra-virgin olive oil; the rest used refined olive oil (sometimes blended with a small amount of virgin), sunflower oil, or other vegetable oils. This reflects the price gap: EVOO is a premium ingredient, whereas refined olive oil has a milder taste and a higher smoke point suited for canning processes. In fact, processors often fry or precook fish in refined oils for stability. For instance, one study on canned eels used refined sunflower oil for frying, and a mixture of refined and virgin olive oil as the packing medium. This blend approach gives some olive flavor and aroma without the full cost of EVOO.
- Sunflower Oil: Sunflower oil is valued for its neutral flavor and light texture. It doesn't overpower the taste of the fish, which can be an advantage for delicate seafood. It's also relatively cheap and abundant on global markets. Standard sunflower oil is high in polyunsaturated fatty acids (omega-6), which are nutritionally desirable but can be prone to oxidation. To address this, some producers may use high-oleic sunflower oil (a modified type with more monounsaturated fat) for greater oxidative stability, or add antioxidants (more on that later). Sunflower oil is extremely common in canned fish. In fact, the majority of canned fish oil worldwide is sunflower oil. Many European sardine and mackerel brands use refined sunflower oil as the default packing medium, unless they are marketing a premium olive oil line.
- Soybean and Other Oils: Soybean oil is often used in canned tuna and other products labeled “in vegetable oil.” It’s neutral in taste like sunflower oil, and generally even cheaper on the global market. However, soybean oil (and certain other seed oils) contain higher proportions of polyunsaturated fats that can break down during the high-heat canning process. Some Asian and American producers rely on soybean oil for cost-effectiveness. There’s also palm oil, which is very stable and inexpensive. However, it is rarely used in high-end canned fish due to its strong color/flavor, as well as sustainability concerns. During the 2022 sunflower oil shortage, many food processors avoided switching to palm oil despite its availability due to consumer perception and environmental issues. Sesame oil is an interesting outlier: it’s uncommon in commercial canning, but research has shown that sesame oil can perform exceptionally well. In one experiment, tuna canned with 18% sesame oil had the highest oxidative stability and was preferred in taste panels over soybean oil. Still, due to cost and flavor profile, sesame oil remains a niche choice – olive, sunflower, and soybean oils continue to be the workhorses of the industry.
Regional preferences
Traditions influence oil selection. Mediterranean producers famously pack sardines and anchovies in olive oil, a practice that has been passed down through generations, which lends a distinct character (and marketing cachet) to these products. In Northern Europe and the US, milder-tasting oils, such as sunflower or soybean, are more commonly used for herring, salmon, or tuna, partly due to consumer familiarity and cost considerations. Thus, a cannery's choice of oil is both a technical decision and a marketing one: it signals product positioning. A can of wild-caught tuna in olive oil appeals to the gourmet segment, whereas tuna in “vegetable oil” or brine targets price-conscious buyers.
Impact on flavor, texture, and preservation
The covering oil's influence extends well beyond oxidative protection to affect the fundamental sensory and physical characteristics that determine consumer acceptance and product longevity. In summary, using edible oil as the packing medium provides multiple benefits for canned fish quality:
Enhancing flavor & texture
Oil adds richness and a pleasing mouthfeel to the fish. For instance, sardines or tuna packed in olive oil are often described as more tender and “buttery” than those in water. The oil carries savory flavors and can even enhance aroma. Tuna in olive oil has a juicy, succulent bite, whereas tuna in brine may taste drier and less flavorful by comparison. Consumers often have strong preferences. Some love the richness of olive oil, while others might prefer the lighter impression of sunflower oil on the palate. In blind taste tests, the oil can tilt the favorability: one study on canned European eel found that panelists actually preferred eels packed in sunflower oil over those in olive oil, indicating the lighter sunflower oil let the fish’s own taste and texture shine through for many consumers. Notably, that study found preferences varied with age and gender, showing that “best flavor” can be subjective.
Moisture retention
During retort sterilization (when cans are heated to ~115–121 °C), fish without added oil or liquid can lose moisture and come out dry. Oil effectively seals in the fish’s natural juices. It surrounds the fish pieces and reduces dehydration during cooking. This is why a mackerel fillet in oil can remain silky, whereas the same fish in a dry pack would be quite firm or chewy.
The oil fill acts somewhat like a confit medium, it keeps the proteins from drying out under heat. As a bonus, this oil transfer means when you open the can, the fish is bathing in flavorful oil, often used by consumers as a sauce or condiment (like drizzling the oil over a salad or using it for cooking, ensuring no flavorful fat goes to waste).
Oxidation protection (shelf life)
Filling the can completely with oil leaves very little headspace air, which drastically cuts down oxygen exposure. Less oxygen means slower oxidation of both the fish’s fats and the oil itself. Furthermore, certain oils possess antioxidant properties: extra-virgin olive oil, for example, is rich in polyphenols and tocopherols (vitamin E) that can inhibit lipid oxidation even during the high-temperature canning process. Research has demonstrated that using antioxidant-rich oils or adding natural antioxidants to the packing medium significantly enhances the lipid stability of canned seafood. In other words, the right oil helps keep the fish tasting fresh and prevents the development of rancid off-flavors over time.
Chemical analyses back this up. In one experiment, canned fish packed in extra-virgin olive oil showed the lowest levels of oxidative degradation products after storage, compared to fish packed in refined seed oils. The natural antioxidants in the olive oil curtailed the formation of oxidation by-products.
Another fascinating long-term study examined canned sardines stored for 15 years. They found that while some of the fish’s omega-3 fatty acids migrated into the covering oil, there were only minimal signs of oxidation in the oil, indicating a remarkably low oxidative status even after a decade and a half. The oil had effectively protected the fish (and itself) from spoilage, acting as a time capsule for flavor and nutrients.
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Sourcing and sustainability: The growing complexity of oil selection
Environmental and sustainability considerations have become central to covering oil procurement decisions, driven by regulatory requirements, retailer standards, and consumer demand for transparency. Each primary oil type presents distinct sustainability challenges that require different solutions.
Olive oil: Climate volatility and regional concentration
Olive production concentrates in the Mediterranean basin, Spain, Italy, Greece, Tunisia, and Turkey, which account for over 80% of the global supply, creating both geographic advantage and vulnerability. While traditional cultivation supports biodiversity and cultural heritage, the rapid expansion of super-high-density plantations around water resources raises concerns about water consumption and ecosystem impacts.
Mediterranean producers have responded with certification programs addressing environmental and social criteria. Portugal's Olivum program, covering 70% of national production, certifies sustainable cultivation practices, including soil biodiversity and water management. The OliveOilMedNet initiative across seven countries develops authenticity verification systems and sustainable methodologies.
Climate impacts pose persistent risks to supply continuity. After years of drought-driven shortages that pushed prices above €7/kg in 2023-2024, Mediterranean production recovered dramatically in 2024/25. Spain achieved a record output of 1.41 million tons, triggering a substantial price correction throughout 2025. These supply fluctuations complicate planning for manufacturers requiring consistent specifications and costs.
Sunflower oil: Geopolitical exposure and innovation
Ukraine and Russia together account for approximately 60% of global sunflower production, making this commodity uniquely vulnerable to disruption from the Black Sea conflict. According to FAO data from September 2025, sunflower oil prices continued rising due to slow harvesting progress and deteriorating production in the region. This persistent supply tightness forces producers to evaluate alternatives or shift to high-oleic varieties, which offer better thermal stability despite premium pricing.
Sustainability focus for sunflower centers on agricultural practices, crop rotation, and soil conservation, rather than ecosystem impacts common to olive cultivation. Certification schemes remain less developed than for olive oil, though demand for verified sustainable sourcing is increasing.
To navigate continued price volatility, many processors now combine long-term contracts with diversified sourcing strategies. For those seeking more control over quality and cost, Wikifarmer Marketplace offer direct access to verified suppliers of bulk olive and sunflower oils. This can help ensure traceability, reduce intermediary markups, and provide flexibility when traditional supply chains face pressure.
