In the summer night market, how can we not have crayfish for supper? A large basin of crayfish placed in front of you will truly make you salivate, making you unable to resist showing off.
However, there are many rumors about crayfish among the people, making some friends hesitant to eat them. For example, some say crayfish cannot be eaten with watermelon, crayfish are dirty, heavy metal exceeds the limit, have parasites… Are these true? This article will interpret these questions.
1. Crayfish are delicious, more nutritious than regular shrimp?
We usually eat mostly South American white shrimp, which already have a relatively low energy content in meat, only about half that of pork loin. The energy of crayfish is only 72kcal/100g, [1] which is slightly lower than that of South American white shrimp, probably 87% of South American white shrimp.
The lower energy content of crayfish is mainly due to slightly lower protein content, but this does not mean that crayfish are not nutritious. It is still a high-protein food, with protein content comparable to pork.
In addition, both have low fat content, which is very friendly for those watching fat intake, but the amount of oil used in cooking should be considered separately.
The cholesterol content of crayfish is lower than that of ordinary shrimp, about 61% of shrimp. This slight difference is insignificant for healthy individuals, but is more friendly for friends with abnormal lipid metabolism or hypercholesterolemia.
In addition, the sodium content of crayfish and South American white shrimp is not high, which is very friendly for hypertensive individuals who need to strictly control sodium intake. The zinc content of crayfish is higher than that of ordinary shrimp, about 1.6 times that of shrimp.
Summary: Both have low energy and are high-protein, low-fat ingredients, with South American white shrimp having slightly higher protein content. However, crayfish have a slight advantage in cholesterol and sodium, so it’s good to diversify your seafood choices.
2. Spicy crayfish is too oily, afraid to eat when trying to lose weight?
Some friends say that although crayfish itself is low in fat, it cannot resist being cooked in a spicy way, and are afraid of gaining weight.
Actually, the spicy crayfish made in restaurants is not as oily as you may imagine. Why is that?
Crayfish itself does not absorb oil like potatoes or eggs; we do not know the exact amount of oil absorbed by them, but we can refer to the fat content of frozen spicy crayfish since they are made according to popular taste, which should be similar to those made in restaurants.
Look, these four spicy crayfish I randomly searched for have a maximum fat content of 7.7g/100g, which is only half of the fat content of fried potatoes or fried eggs (15g/100g).
So eating spicy crayfish will not make you gain weight significantly. If you want to control your energy intake as much as possible, just go lightly on the sauce.
If you are cooking at home, you can refer to my method, I use only a small amount of oil.
Heat the pan and add dry chili, minced garlic, green onion, and ginger to sauté until fragrant. Add a spoonful of Pixian bean paste and the crayfish. Once the crayfish turns red, pour in a can of beer, stew over high heat for 10 minutes, then serve. The amount of Pixian bean paste should be adjusted based on the saltiness of the crayfish.
3. Can’t watermelon be eaten together with crayfish?
Unbearably hot summer days, thankfully, with chilled watermelon and spicy crayfish, biting into watermelon and savoring crayfish in the air-conditioned room after work, all the heat and fatigue from the day will vanish. However, some say watermelon and crayfish cannot be eaten together, is that true?
Saying both cannot be eaten together because they are both ‘cold’ in nature, eating them together might cause diarrhea or abdominal pain due to the excessive ‘cold’ properties is an oversimplified suggestion that violates the principle of traditional Chinese balance in health maintenance practices. Even if some individuals may be sensitive to ‘cold’ foods, it does not mean they cannot eat them at all.
Therefore, it is scientifically unsound to say that both cannot be eaten together. Moreover, crayfish is often cooked with ‘hot’ chili peppers, and even if the combination might seem overly ‘cold,’ it could be balanced out to some extent.
Another reason given for not eating them together is that watermelon is rich in tannic acid, while crayfish is rich in calcium, implying that eating both together affects calcium absorption and irritates the stomach, but this view lacks nutritional understanding.
Foods rich in tannic acid usually have an astringent taste, such as the thin skin of persimmons, walnuts, while watermelon only tastes sweet and not a bit astringent, clearly indicating low tannic acid content. As for calcium in crayfish, the content is only 25mg/100g, a meager amount compared to milk or green leafy vegetables like oilseed rape, bok choy, or amaranth. Therefore, this reason is also unfounded.
In the scorching summer, sweating heavily, watermelon is exceptionally hydrating, with a sweet taste, while crayfish is rich in high-quality protein, offering a spicy and appetizing flavor, making them both suitable for summer consumption, and enjoying them together is pleasant.
However, the Chinese dietary guidelines suggest consuming 200-350 grams of fruit per day, which is incompatible with indulging in large amounts of watermelon all at once, especially for individuals with high blood sugar levels. As a snack, consuming 100-200 grams of watermelon at a time is more appropriate, while for crayfish, cooking with less oil and salt is recommended. Even if indulging in 500 grams, the edible portion should not exceed 150 grams. For healthy individuals who do not frequently consume fish or shrimp, occasionally consuming a bit more in a week is still acceptable.
4. What to do if delivered crayfish are not clean enough?
Even if they are not washed clean, there is no safety issue after high-temperature cooking, but we may feel dirty mentally. This is similar to boiling eggs water, which can be sterile but may feel dirty due to eggshell residues in the water.
If you cannot accept that the delivered crayfish may not be clean enough, then you can make them at home!
5. When buying frozen crayfish, look at three indicators
In addition to fresh crayfish made at home or in stores, you can also buy frozen crayfish with spicy or garlic flavors, which can be ready to eat in 3 minutes after thawing in the microwave, stocking up some at home for quick meals.
When buying, choose those with high solid content so you can get more shrimp for the same net weight. I’ve seen that most frozen crayfish have a solid content of ≥55%, but there are also those with higher solid content, such as the one below with a solid content of ≥67%.
Furthermore, look at protein and sodium content, choosing those with high protein content and relatively low sodium content, like the two examples below, the one with higher protein content and lower sodium content than the other.
6. Do crayfish live in dirty ditches?
Crayfish are quite helpless.
Crayfish can indeed survive in dirty ditches, but this is just for survival, an ability they had to develop out of necessity. Yet, they prefer a clean environment.
Thus, the ponds where crayfish are raised need to have regular drainage, removal of excess sludge, sterilization of pathogens through exposure to sunlight or freezing, and regular water changes to maintain water quality, only then will crayfish thrive and yield more. [2]
Experiments also show that crayfish are not attracted to high concentrations of ammonia nitrogen wastewater; on the contrary, they will actively avoid it when the concentration reaches a certain level. Failure to avoid it may lead to abnormal behavior or even death. This indicates that crayfish also prefer clean water sources, and dirty water is not conducive to their survival and reproduction. Therefore, crayfish raised in artificial environments are not as dirty as you may think.
7. Are crayfish contaminated with heavy metals beyond the standard limit?
If we talk about ingredients that are prone to exceeding the standard limit of heavy metals, then it is definitely large fish because they are at the higher end of the food chain, consuming small fish and shrimp, which in turn eat water plants, leading to the accumulation of heavy metals. The higher the animal is in the food chain, the higher will be its heavy metal content.
However, crayfish mainly feed on water plants, making them animals at the bottom of the food chain, so theoretically, their heavy metal content should not be too high.
In fact, crayfish are not prone to exceeding the standard limit of heavy metals. Experiments [3] have been carried out on crayfish from environments such as sewage ditches, rice fields, and aquaculture ponds, testing for heavy metals such as lead, cadmium, mercury, arsenic, and chromium. The results show that except for the chromium content in crayfish from industrial areas exceeding the standard limit, all other tested indicators are within the permissible range.
Furthermore, research shows that the water pollution situation of heavy metals in the Yangtze River’s middle and lower reaches, in some crayfish-producing regions of five provinces, is severe, with lead, cadmium, and mercury levels in water bodies and sediments exceeding the standard by more than 150 times.
There is a clear difference in the accumulation of heavy metals in different parts of crayfish, mainly in the organs and shell, while the amount in edible muscle parts is relatively low. Additionally, buying crayfish raised for consumption, further reduces the risk of heavy metal exposure.
Moreover, crayfish purchased at large supermarkets undergo strict inspection and quarantine before being put on the market. The parts of crayfish with the most accumulation of heavy metals, such as the shell and internal organs like gills, are not consumed by us, so there is no need to worry about crayfish being contaminated with heavy metals beyond the standard limit.
8. Do crayfish have parasites?
This is not unique to crayfish.
Actually, various aquatic products carry parasites, so this is not exclusive to crayfish. However, parasites are afraid of high temperatures, so boiling or steaming crayfish for 10 minutes ensures they are fully cooked, and there is no need to worry about parasites.
Just marinating them in wine to make drunken crayfish may not necessarily kill parasites, so you need to pay attention to this.
9. Can eating crayfish lead to rhabdomyolysis?
Rhabdomyolysis syndrome, also known as haff disease, refers to the dissolution and destruction of muscle cells in the human body, manifested as muscle pain.
There may be some association between Haff disease and crayfish, and not just crayfish, this condition typically occurs after consuming large amounts of water products or intense excessive exercise, so even if overindulging in other aquatic products, it may also lead to Haff disease, such as shellfish, freshwater fish, saltwater fish, and so on.
The probability of Haff disease is very low, so there is no need to worry excessively. To prevent this condition, it is recommended to purchase crayfish from reputable establishments and control the intake amount, avoiding eating large amounts frequently.
In conclusion:
Crayfish are not only delicious but also nutritious, with the key factor being their low calorie content, making them suitable for indulgence even for those watching their weight. Spicy crayfish, garlic crayfish, steamed crayfish are all good cooking methods, with the key being that they should be cooked thoroughly!
References:
[1] https://fdc.nal.usda.gov/fdc-app.html#/food-details/175169/nutrients
[2] Tang Jianqing, Xia Aijun, Yan Weihui. Environmental Requirements for Crayfish Farming[J]. Nongjia Zhifu, 2014(22):38-39.
[3] Wu Kunjie, Peng Xinliang, Pan Kaiyu, et al. Evaluation of Heavy Metal Levels in Crayfish from Different Sources in Xinyang City[J]. Hubei Agricultural Sciences, 2014, 53(16):3904-3906.
