The heavy metal content in popular summer food exceeds the standard and may also cause parasite infection?

A summer without showing off crayfish is incomplete.

But every time I was enjoying my meal, someone would whisper in my ear:

Crayfish are dirty! They like to live in sewers!

Heavy metals in crayfish exceed the limit! Especially yellow ones!

Crayfish have parasites, be careful not to get worms all over your body if you eat them!

I really want to thank you... How can I eat this!

In order to study whether there is any problem with crayfish, we bought 6 types of crayfish this time and prepared to test them.

Among them are live shrimps bought from the market:

There are also cooked shrimps bought from major restaurants and e-commerce platforms, as well as crayfish caught by my colleague’s mother in the original (small) production (pond) land (pond).

It adds up to more than 30 kilograms.

Finally, 6 samples were collected:

01

How much heavy metals are contained in crayfish?

Rumor has it that crayfish have a hobby: collecting heavy metals in the water and storing them in their bodies.

Therefore, their heavy metal content is seriously above the standard, and eating too much can easily lead to poisoning.

So this time, we gathered a group of shrimp peelers to divide the crayfish into three parts: shrimp roe, shrimp meat (including shrimp thread), and shrimp shell.

Because many friends were worried about the shrimp thread, this time we deliberately did not remove the shrimp thread and tested the meat together.

In order to take care of those who like to eat shrimp heads, shrimp roe is also specially added. Friends who like to eat shrimp roe, please give more likes

Then it was sent for testing of five heavy metal contents.

The test results are as follows:

None of the five heavy metals exceeded the standard

*Because the total arsenic content of shrimp roe No. 2, 4, 5, and 6 exceeded the limit of inorganic arsenic (0.5 mg/kg), we also tested the inorganic arsenic content.

The results also meet the limit requirements for inorganic arsenic.

To summarize the test results:

All five heavy metals in the samples (meat, yolk, and shell) were below the limit. Friends who are worried about excessive heavy metals can now rest assured.

In fact, crayfish are also afraid of heavy metals.

In order to protect themselves, they will transfer the absorbed heavy metals to their shells and heads (gills and internal organs), and then excrete the heavy metals through growth and molting.

Therefore, the distribution of heavy metals in most crayfish is shrimp roe content > shrimp shell > shrimp meat.

The crayfish we tested this time also happened to conform to this rule (taking the cadmium test results as an example):

So there is no need to worry, as long as the crayfish are farmed in a formal manner, the meat can be eaten with complete safety.

As for shrimp roe, although the heavy metal content is not excessive, we still recommend that you eat less of it. I will explain the reason later.

One more thing, the cadmium content of No. 6 shrimp roe (crayfish caught from ponds) is a bit close to the limit.

It seems that there is still a certain risk of exceeding the standard for wild crayfish, so try not to eat them.

02

Do crayfish love to dig into stinky ditches and eat garbage?

In the eyes of the elders, crayfish live in places like this:

Not only do they like to live in dirty water, they also eat garbage and carrion.

Plus, some crayfish are so horribly dirty, which makes this rumor more and more true...

As a righteous person as I am, I can't help but say something on behalf of the crayfish: It's unfair!

Crayfish have a strong ability to adapt and can survive even in harsh environments (such as sewage ditches).

But that doesn't mean they like dirty environments.

On the contrary, if the water quality in the living environment is too poor, it will lead to the death of crayfish.

An expert once did an experiment:

He made a device like the one shown below, with clean water at one end and artificial sewage at the other. He placed crayfish in the gate and watched which end they would choose to crawl to.

The results showed that 80% of the crayfish chose to crawl towards the clean water side, and 20% chose the dirty water side.

It seems that if they have a choice, they would rather live in clean ditches.

As for their love of eating garbage... crayfish are omnivores, and if they live in the wild and there is not enough food, they might eat a few bites of garbage.

But nowadays, there are no longer enough wild crayfish for everyone to eat.

In order to ensure that crayfish have good food and water and avoid a sharp drop in production due to harsh environment, some crayfish farmers have also begun to pursue scientific breeding.

More high-end farms also feed crayfish with frozen sea fish, corn, and soybeans.

Look at this breeding environment, it’s not inferior to fish and shrimp.

03

Do crayfish have parasites?

Some people also say: Crayfish have parasites! If they are not cooked well enough, the parasites inside will live in the human body and may even crawl into your lungs and brain!

There are also frequent reports in the news: A lady loves to eat crayfish, but as a result, her lungs were drilled with many holes by lung flukes!

We went to the market and a restaurant to buy three live shrimps and sent them to the laboratory for parasite testing.

Referring to the "Inspection Methods for Parasites in Imported and Exported Foods" SN/T 1748-2006, the technicians mashed the crayfish and digested them, and used a dissecting microscope to observe whether there were foodborne parasites in the digested samples.

The results were negative.

Seeing this, are crayfish lovers ecstatic?

Wait a minute!

Although it was not detected this time, most crayfish do have a risk of parasites (such as sparganosis and paragonimiasis).

For safety reasons, it is recommended that you cook the shrimp thoroughly before eating. If you cook it yourself, it is recommended to boil it and then simmer it on low heat for 30 minutes.

Image source: soogif

By the way, other aquatic organisms (such as crabs, frogs, snails, shellfish, fish, water chestnuts, and wild rice stems) also have parasite problems.

Make sure it is fully cooked before eating!

04

Crayfish is high in calories, will you get fat if you eat too much?

Big NO, special NO!

Crayfish is not only low in calories, but is actually a very good weight loss food.

One pound of steamed crayfish (only the shrimp meat) has only 82 kcal, which is less than the calories in an apple.

Even the spicy crayfish, which is high in oil and salt, only has 107 kcal per pound, which is not much higher than the steamed variety.

Plus it’s low in fat and high in protein, making it perfect for people who want to lose weight.

Why do I gain 3 pounds after eating crayfish?

Come, reflect on whether you have done these 3 things:

Shrimp roe contains 58% fat, which can make you fat easily if you eat it. For those of you who want to lose weight, you know this.

The soup is high in oil and salt, and if you add in beverages, it is easy to get edema and gain three pounds in one meal.

If you want to eat shrimps without getting fat, I have a tip for you: eat only the meat and don’t eat the shrimp heads; choose steamed shrimps or eat them in less soup; drink less beverages!

Shrimp red has been surrounded by controversy, but fortunately, this time its reputation has finally been cleared.

We have summarized a guide for eating shrimps, and you are welcome to forward it to your friends who love to eat crayfish:

Well, remember to forward this article to your friends who love shrimp. Tonight, enjoy shrimp with peace of mind!

Editor | Cai Cai

Design | Sour