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Canned fish

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Canned fish refers to seafood that has been processed and sealed in airtight containers. These containers are often metal tin cans. This method is a way of preserving food to make it last longer. Most canned fish can stay on a shelf for one to five years.

Canned and packaged tuna on supermarket shelves
Canned and packaged tuna on supermarket shelves

This process is vital because fish have low acidity levels. In science, acidity is measured by pH levels. Fish have a pH higher than 4.6, which is considered low acidity. At these levels, microbes can grow very quickly and cause spoilage.

To keep the fish safe, the containers must undergo sterilization. This means using very high heat to kill microorganisms. Because the heat must be higher than the boiling point of water, workers use pressurized cooking. This pressure allows the temperature to rise above what a normal pot could do. This step is necessary to eliminate dangerous microbes like Clostridium botulinum. This specific bacterium can cause a serious illness called botulism. Once the can is sealed after sterilization, no new microorganisms can enter to grow inside.

Chicharros en escabeche
Chicharros en escabeche

Different types of fish require different preparation steps. For sardines, or pilchards, the process often begins with washing the fish. Workers remove the heads and sometimes the guts, which is called eviscerating. Some sardines are deep-fried or steam-cooked before they are dried. They are then packed tightly into small cans with olive oil, sunflower oil, or soybean oil. Other varieties use water or sauces made of tomato, chili, or mustard. Because they are packed so closely, people use the phrase "packed like sardines" to describe crowded places.

Chicharros en escabeche
Chicharros en escabeche

Tuna processing follows a specific sequence of events. First, the tuna is usually gutted by hand. It is then precooked for a duration of 45 minutes to three hours. After precooking, the fish is cleaned and filleted. The dark lateral blood meat is often set aside to be canned separately for pet food. The fish is then placed in cans with water, brine, or vegetable oils. The final step is called retort cooking. The sealed cans are heated for two to four hours to ensure all bacteria are destroyed.

History shows how much technology changed food storage. In 1795, a Frenchman named Nicolas Appert began experimenting with fish in glass jars. He placed these jars in boiling water to preserve the contents. During the Napoleonic Wars, the French government offered a 12,000 franc prize for a way to feed large armies. Appert won this prize in January 1810. However, glass jars were difficult to transport without breaking. Shortly after, a British inventor named Peter Durand patented the use of tin cans. This invention created the modern canning process we use today.

The salmon canning industry grew rapidly in North America. In the 1830s, Scotland used canning to keep fish fresh for markets. By the 1840s, salmon canning began in Maine and New Brunswick. The first industrial-scale salmon cannery was built in 1864 on a barge in the Sacramento River.

Pacific Coast first salmon cannery
Pacific Coast first salmon cannery

By 1883, the Columbia River had become a major center for this industry. At that time, 39 canneries were operating. These factories used 1,700 gillnet boats to supply 15,000 tonnes of salmon, mostly Chinook, every year.

Canned fish remains a significant part of the modern food system. In the United States, canned tuna is used in many common meals. About 52% of canned tuna is used for sandwiches. Another 22% is used for salads, and 15% goes into casseroles or meal mixes.

Canned and packaged tuna on supermarket shelves
Canned and packaged tuna on supermarket shelves

Scientists also monitor the quality of these products. For example, they check for histamine, which can cause rancid flavors. The international standard limits histamine to 200 milligrams per kilogram. This ensures that the food is both safe and tasty for everyone.

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File:Chicharros en escabeche.jpg
Chicharros en escabeche.jpg
File:Pacific Coast first salmon cannery.png
Pacific Coast first salmon cannery.png
File:Canned and packaged tuna on supermarket shelves.jpg
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