In fact, it is not difficult for careful netizens to find that whenever this kind of seafood is on the market, a big wave of rumors about aquatic products will circulate on the Internet. The content of the rumor is nothing more than water injection, glue injection and birth control pills. In this issue, we will concentrate on firepower and ask experts to catch all these rumors about aquatic food. After reading, you can eat your seafood feast in a down-to-earth manner.
Glue Pipi shrimp? Live shrimp becomes dead shrimp, which is equal to losing money.
"Pippi shrimp can't be eaten, and they are all glued by black-hearted traders to gain weight!" Recently, a video about Pippi Shrimp went viral on the Internet.
In the video, a woman peeled off a plate of cooked Pippi shrimp on the table and took out a white or yellow gelatinous body inside. The woman said that this is Pipi shrimp bought in the market in the morning, and the shrimp meat was injected with glue by black-hearted vendors to gain weight. "Everyone has it, so don't eat this Pipi shrimp."
Hearing this, Yang Weilong, vice president and senior aquatic engineer of the China Fisheries Association, was in distress situation. He told the Science and Technology Daily reporter: "It was not' artificial glue injection' at all, but the gonad of Pipi shrimp, also known as shrimp yellow and shrimp paste."
Yang Weilong introduced that there are many kinds of Pippi shrimp, which is officially called Squid. Among them, Mouth Squid is the most common one. It is one of the few shrimps that can live in temperate zones, so it is produced in large quantities in the north and south coasts and is the most commonly eaten one. Its individual is not big, its body length is generally only a dozen centimeters, its back is milky yellow, accompanied by bluish gray, its abdomen is white, and it is plain but attractive. April is the breeding season of Pipi shrimp every year. Before its development is completely mature, the jelly will appear in the shrimp, and the jelly of the female shrimp will eventually grow into eggs, which are concentrated from the chest to the tail and are yellow or red, while those of the male shrimp are white, so people don't have to worry.
"We know that the most important thing for aquatic products is to ensure the survival rate, and only when the survival rate is high can they be sold at a good price. Most aquatic products and marine products, whether cultured artificially or grown naturally, will not be artificially injected with glue, because once injected with glue, aquatic products will soon die. How can farmers and traders do such a loss? " Yang Weilong said.
So, is there any glue-injected shrimp? There really is.
Some experts pointed out that some merchants will inject glue into the frozen shrimp, in order to keep the connection between the shrimp head and the shrimp body and make the shrimp look more beautiful. However, most of these gums are seaweed gelatin, which is edible. Its raw materials are boiled animal bones, skin and tendons, and most of them are used to make jellies and other desserts.
"Merchants inject glue into frozen shrimp mainly to increase the weight of shrimp. After glue injection, the weight of a shrimp can be increased by 20% to 30%. In addition, glue injection will make the shrimp body fuller, keep fresh hand feeling, even cover up the shortcomings of shrimp meat deterioration, and prevent the shrimp head from falling off from the body during transportation. But it is absolutely unnecessary to inject glue into live shrimp. " Zhuo Zhuangsheng, an expert in Guangdong fishery industry, said.
Water hairy crabs? Water will flow out from the gap, making it difficult to gain weight.
Besides shrimp, crabs are also the hardest hit areas for rumors. Rumors about crab water injection have never stopped on social platforms such as WeChat and Weibo.
What's the purpose of injecting water into crabs? Yang Weilong said, "It's nothing more than gaining weight. But this possibility is almost impossible, because, like Pippi shrimp, the osmotic pressure of the environment will change dramatically after the liquid is injected into the crab, and the crab's organs will either lose water or absorb water, which will lead to its rapid death. Fishermen and traders can't turn live crabs into dead crabs just to gain a little weight and do business at a loss. "
Then, some people reported that pinholes were indeed found on the crabs they bought. Where did this hole come from?
In this regard, some media reported that most people bought swimming crabs, and the shells on crabs were so hard that ordinary syringes could not be inserted at all. The hole in the body of Portunus trituberculatus may be because vendors put it together and put it in baskets. The spikes on the legs or bodies of the crabs collide and squeeze each other, which will make holes in the body.
"Moreover, the tissues in the crustaceans of crabs have poor water absorption, and if liquid is injected, it will flow out from the cracks in the crabs' bodies. That is to say, even if the hard shell is punctured and the liquid is injected, it will still flow out, and it will not gain weight. " Yang Weilong said.
Feed birth control pills to all kinds of aquatic products? Crawfish prolong the growth period; Crabs and eel will die.
Apart from water injection and glue injection, the rumor that people have heard the most in recent years is that in order to increase production, so-and-so aquatic products grew up on birth control pills, and the discredited aquatic products include crayfish, hairy crabs, turtles and eel, etc. But is this really the case?
"There is no scientific basis for the statement that crayfish are raised with birth control pills." Yang Weilong said, first of all, the growth cycle of crayfish is very short, generally it can be listed in about 3 months, and its sexual maturity is generally 8- 10 months, which means that crayfish are still far from the breeding period when they are listed, and there is no breeding ability at all. Farmers can only increase costs by using contraceptives to raise shrimp; Secondly, crayfish belong to lower invertebrates, and contraceptives of higher vertebrates have no effect at all; In addition, if a large number of hormones are used, it will increase the shelling frequency of crayfish, slow its growth rate, and prolong the growth cycle of crayfish, so farmers will not do so.
And "farmers put birth control pills to promote hairy crabs to grow quickly" is even more nonsense. Yang Weilong said that the smallest crab pond is about 20 mu. Based on the concentration in water 1 g/ton, the whole pond has to put 13 kg of birth control pills, so you can imagine how high its cost is.
In fact, hairy crabs belong to crustacean aquatic animals. They are born in seawater and grow in fresh water, and grow up slowly by shelling. Every year around 10, under the stimulation of salt water, male and female hairy crabs will hug and mate, and they will not mate in freshwater lakes. Not only that, crab owners will also pack crabs in temporary breeding boxes according to their sex before they mature. Crabs need to shell 19-2 1 times in their lifetime to grow up. A large number of experiments show that the use of birth control pills or hormones disrupts the shelling order of crabs, which will lead to a large number of deaths due to dystocia, and it is more likely to lead to the reproduction of green algae, thus destroying the biological chain in the lake and causing greater losses.
"In addition, crab roe and crab paste are both gonads of crabs. If crabs take birth control pills, they will inhibit the growth and maturity of gonads. Without crab roe or crab paste, the taste of hairy crabs will be greatly reduced. Therefore, from the growth principle of crabs, it is impossible to feed birth control pills. " Yang Weilong said.
Chen Shunsheng, a professor in the Department of Aquatic Products Processing and Storage Engineering, College of Food Science, Shanghai Ocean University, pointed out that it is a rumor that eel is fattened with contraceptives in order to make it grow up quickly. Monopterus albus is a rare fish with sexual reversal characteristics. It is all female in its infancy, and some Monopterus albus will gradually transition to male after spawning. Because the female eel consumes a lot of physical energy in the reproductive process, its growth rate is affected to some extent. The male eel has less energy consumption in this process, and its growth rate is relatively fast, and its body size is larger than that of the female eel. In fact, some aquaculture experts have conducted scientific experiments on hormone-fed eel before. The results show that the growth rate of eel with hormone in feed is about 10% faster than that without hormone in one month, but it has caused a large number of deaths: the higher the hormone dose, the higher the mortality rate. This may be because Monopterus albus ate hormone-containing feed, which led to metabolic disorder in the body, increased body fat deposition, and then poor disease resistance and even death. For farmers, this growth rate of 10% is not worthwhile from the perspective of risk or cost.
Tips for Eating Seafood Seafood+Beer Induced Gout
Seafood plus beer is called "gout package" because some fish (such as sardines, anchovies, salmon, etc.), shellfish and shrimps and crabs have high purines. If you eat seafood and drink a lot, it will accelerate the decomposition of purines and produce uric acid, and the ethanol in the wine is not conducive to uric acid excretion, which may induce gout. Not only beer, but also all kinds of alcoholic beverages, if you don't pay attention to the consumption, it may also become a risk factor for gout high-risk groups.
Seafood+cough medicine is easy to cause allergies
After taking some cough medicine, eating seafood such as sea fish may cause discomfort such as flushing, dizziness, rapid heartbeat and urticaria. This may be an allergy caused by histamine. Some fish contain high histidine, which can form histamine by the action of enzymes in the body. Some drugs can affect the inactivation of monoamine oxidase histamine in stomach, intestine and liver, such as cough water containing codeine and compound licorice tablets. Therefore, don't eat seafood while taking western medicine such as cough medicine, conazol and traditional Chinese medicine such as velvet antler; It is not recommended to eat seafood in the short term after stopping the drug.
Seafood+persimmon is easy to have a stomachache
Protein, which is rich in seafood, will combine with tannic acid in fruits and tea, which may seriously lead to degeneration of protein and food poisoning. Moreover, if the tannic acid protein is stuck with pectin and cellulose, stones may be formed. However, as long as the crabs are cooked and don't eat too much persimmons, it won't have much impact on the body.