You thought you were eating deep-sea salmon, but it was actually freshwater rainbow trout?

The name salmon comes from the Cantonese transliteration of the English word "Salmon". Initially, this name specifically referred to Atlantic salmon in the North Atlantic. This silver-scaled giant leaps up the river against the waterfall to lay eggs every year, and is called "the fish that leaps up vigorously" by Europeans. As Pacific salmon from the Pacific coast enter the market, merchants simply expand "Salmon" to a general term for the entire salmon family. In the Chinese market, the concept of salmon is further blurred: in addition to imported Atlantic salmon and Pacific salmon, domestic rainbow trout is also included in the ranks of "salmon", which has caused controversy.

Focus of controversy: Is rainbow trout considered salmon?

The "Raw Salmon" group standard issued by the China Aquatic Products Circulation and Processing Association in 2018 listed rainbow trout as a type of salmon, which caused an uproar. Supporters believe that rainbow trout and salmon belong to the same family, the salmonids, and that the meat quality can be adjusted through feed; opponents point out that rainbow trout belongs to the genus Salmon, which is more distantly related to salmon, and that the risk of parasites in freshwater farming is higher. The US FDA clearly stipulates that rainbow trout packaging must not be labeled "Salmon", and the Norwegian Fisheries Directorate emphasizes that "real salmon must be Atlantic salmon." This naming dispute is essentially a collision between business and science: when "salmon" becomes synonymous with high-end ingredients, can the "freshwater household registration" of rainbow trout obtain the status of "returnee"?

If you put Atlantic salmon and rainbow trout side by side, the difference between the two is obvious:

1. Size and color: Atlantic salmon can grow up to 1 meter in length, with shining silver scales like a deep-sea noble; rainbow trout is smaller in size, with a rainbow stripe running across its side, like a freshwater elf.

2. Meat texture: Atlantic salmon has a thick fat layer, and the orange-red fish meat is interspersed with thick white stripes, like a marble pattern; rainbow trout has a thin fat layer, fine texture, and a pink color.

3. The mystery of taste: When eaten raw, Atlantic salmon is as soft as butter and melts in your mouth, while rainbow trout is slightly tougher and has a stronger earthy smell. Merchants often cut rainbow trout thinner to imitate the delicate taste of salmon.

4. Price code: The wholesale price of imported salmon is about 55 yuan per catty, while that of rainbow trout is only 30-40 yuan. The price difference reveals the mysteries of breeding costs and market positioning.

Atlantic salmon are typical migratory fish: young fish hatch in fresh water, swim to the deep sea to feed when they grow up, and swim upstream to reproduce, completing the life cycle. This "sea-fresh" switching survival strategy makes its muscles rich in Omega-3 fatty acids and its meat is firmer. Most rainbow trout live in low-temperature fresh water for their entire lives, such as the cold water reservoir area of ​​Longyangxia in Qinghai. Their growth rate and fat accumulation are far less than those of marine salmon. Interestingly, there is a type of rainbow trout called "Steelhead" that will grow in the sea and then return to fresh water to reproduce, forming a migratory habit similar to salmon, but it is still difficult to be recognized as "real salmon" due to the difference in meat quality.

The freshwater environment of rainbow trout makes it more susceptible to parasites such as liver flukes and gnathostomima, and eating them raw may cause liver and gallbladder diseases and even cancer. However, the deep-sea parasites of Atlantic salmon (such as Anisakis) have a low survival rate in the human body, so the risk is relatively controllable. However, it should be noted that wild salmon have a higher risk of parasites, and the safety of farmed salmon depends on strict freezing treatment (such as freezing at -20℃ for 7 days).

The protein and Omega-3 content of both are similar, but Atlantic salmon has higher DHA (brain gold), while rainbow trout is rich in vitamins A and D. However, nutritionists point out that the advantage of salmon lies more in the "brand premium" and the actual health difference is limited. If the budget is limited, cooked rainbow trout is also a high-quality protein source.

How can consumers avoid the trap of "rainbow trout impersonating salmon"?

1. Check the label: Regular imported salmon will be marked with "Atlantic Salmon" or the place of origin (such as Norway), while rainbow trout will often be marked with "Rainbow trout" or "Domestic Salmon".

2. Identify the price: If the salmon sashimi is as low as 30 yuan per piece, it is most likely rainbow trout.

3. Check the texture: If the thick-cut fish has fine fat lines and is pink in color, it may be rainbow trout.

4. Choose channels: large supermarkets or brands whose origin can be traced are safer.

There is no difference between rainbow trout and Atlantic salmon - the former is an environmentally friendly option for freshwater farming, while the latter is a nutritious treasure from the deep sea. But when businesses deliberately confuse the two, consumers need to keep their eyes open: after all, paying a high price for a "returnee passport" but buying a "freshwater household registration" is not a pleasant consumption experience. Next time you enjoy "salmon", you might as well ask one more question: "Who are you?"

Trivia Easter Egg

The migration success rate of Atlantic salmon is only 0.1%, which can be described as a "tragic journey towards death."

Rainbow trout is a "darling of scientific experiments" and is often used in ecotoxicology research because it is easy to breed.

Of the "salmon" consumed worldwide each year, about 15% is actually rainbow trout - equivalent to 240 million servings of "misidentified" sashimi!

References:

[1] Shan Qianqian, Zhou Yangen, Xu Ying. Comparison of general nutritional composition and sensory quality of Atlantic salmon, rainbow trout and steelhead trout[C]//Chinese Society of Food Science and Technology. Abstracts of the 18th Annual Conference of the Chinese Society of Food Science and Technology. College of Food Science and Engineering, Ocean University of China; College of Fisheries, Ocean University of China.

[2] Zhang Wen, Wei Lingdong, Zhang Yuming, et al. Comparative study on meat quality and nutritional composition of farmed rainbow trout and Atlantic salmon[J]. Journal of Animal Ecology, 2021, 42(01): 74-78.

[3] Ding Qinglong, Zeng Xiaocong, Zhou Lu, et al. Investigation on adulteration of salmon aquatic products[J]. Journal of Food Safety and Quality, 2019, 10(13): 4080-4085.