100-year egg
food
abstract
Also known as preserved eggs, preserved eggs and so on. , a traditional flavor egg product in China, is not only deeply loved by domestic consumers, but also famous in the international market.
kind
Lead-free preserved eggs: lead oxide (yellow lead powder) is added to the traditional preserved egg processing formula in China. Because lead is a toxic heavy metal element, some countries have made regulations prohibiting the sale, which has affected the sale of preserved eggs exported to China. Therefore, the relevant scientific research departments have studied the substitute substances of lead oxide, among which EDTA and FWD have better effects. When EDTA (ethylenediamine tetraacetic acid) is used, the formula and processing technology of other auxiliary materials remain unchanged, as long as lead oxide is removed and EDTA is used instead. Generally processing 1000 duck eggs, the dosage is 0. 12 ~ 0. 13 kg. FWD is a substance synthesized by trace elements magnesium and manganese. Its usage is to dissolve 0.5 kg FWD in 75 kg cold boiled water to make 1500 duck eggs. The formula and processing method of other auxiliary materials are the same as when lead oxide is used.
Product characteristics
Finished preserved eggs, eggshells are easy to peel and do not adhere, the protein is translucent brown solidified body, the surface of the protein has pine-like patterns, the yolk is dark green solidified, and some have sugar hearts. The cut egg pieces are mottled and rotten. The food is cool and refreshing, fragrant but not greasy, and delicious.
quality test
The quality inspection and grading of preserved eggs is the last important process for manufacturers and should be carried out in accordance with relevant state regulations. Consumers should also make choices when buying goods. The commonly used methods for quality inspection of preserved eggs are: first observation, second weighing, third shaking and fourth photographing.
One view: Look at whether the packaging material is moldy, whether the eggshell is complete and whether the shell color is normal (the green cylinder color is better).
Second, put the egg in your hand, gently throw it up and throw it several times in a row. If you feel elastic and trembling, the heavier egg is a good egg, otherwise it is a poor egg.
Three shakes: hold both ends of the egg with your thumb and middle finger, shake it up and down in your ear, and hear the sound of water or impact. If you can't hear the sound, it's a good egg.
Photo 4: If most eggs are black or dark brown and a few are yellow or light red, they are high-quality eggs. If most of them are yellow-brown transparent body, they are immature preserved eggs.
manufacture
How did the pine flowers on the pine eggs come from? Is actually produced by a chemical reaction:
The main chemical component of protein is a kind of protein. When eggs are kept for a long time, some protein in protein will break down into amino acids. Do you know amino acids? Its chemical structure has a basic amino group -NH2 and an acidic carboxyl group -COOH, so it can react with acidic and alkaline substances. Therefore, people deliberately added some alkaline substances, such as lime, potassium carbonate and sodium carbonate, in the design of making preserved eggs. They will pass through the holes in the eggshell and combine with amino acids to form amino acid salts. These amino acid salts are insoluble in protein, so they crystallize in a certain geometric shape to form beautiful pine flowers.
Why is the yolk of preserved eggs bluish black? In fact, this is also caused by chemical reactions:
The main chemical composition of preserved eggs is another kind of protein, which contains sulfur. After a long time, the egg yolk will also decompose into amino acids, and release what we usually call rotten egg-flavored gas-hydrogen sulfide. Egg yolk itself contains many minerals, such as iron, copper, zinc and manganese. Hydrogen sulfide can react with these minerals to form sulfide. Therefore, the blue-black yolk is the source of these sulfides. Most of these sulfides are extremely insoluble in water, so they are not absorbed by the human body.
In addition, because a large amount of protein in preserved egg yolk is decomposed into amino acids, the yolk of preserved egg tastes much fresher than ordinary eggs. Preserved eggs are nutritious and delicious, but they are too alkaline to eat.
Suggestion: Add some old vinegar when eating preserved eggs, which can sterilize, neutralize some alkalinity of preserved eggs and taste more delicious.
side effect
Many people know that preserved eggs contain lead, so people buy lead-free preserved eggs and think they can eat them safely. In fact, lead-free preserved eggs also contain lead, which is ok for adults, but children should eat less.
When processing preserved eggs, soda ash, lime, salt and yellow lead powder should be mixed in a certain proportion, and mud and bran should be wrapped outside the duck eggs. Two weeks later, the delicious preserved eggs are ready. Plumbum preparatium powder is lead oxide, which can make eggs produce beautiful patterns, but with Plumbum preparatium powder, preserved eggs will be polluted by lead. According to the national regulations, the lead content of preserved eggs per1000g should not exceed 3mg, and preserved eggs that meet this standard are also called lead-free preserved eggs. Therefore, "lead-free preserved eggs" are not lead-free, but lead content is lower than the national standard.
Chinese medicine believes that children's bodies are "young yin and young yang" and their metabolism is extremely vigorous. Trace lead in "lead-free" eggs will remain in tissues such as liver, lung, kidney, brain and red blood cells after being absorbed by children, and will also cause calcium loss in bones and teeth. Regular consumption of "lead-free preserved eggs" will cause bone and tooth dysplasia, loss of appetite, gastroenteritis and so on. In children, it will also affect intellectual development.
Lead-free preserved eggs are delicious and nutritious, but children are in a stage of vigorous physical development and have obvious reactions to the harm of lead, so it is better to eat less.
Summer is hot, and most people like to entertain themselves with preserved eggs when drinking beer, or treat the whole family with cold preserved eggs. It may never occur to them that preserved eggs may also cause food poisoning.
According to the inspection and analysis of relevant food experts, there are only 400-500 bacteria on clean eggshells, while there are as many as10.40-0.40 billion bacteria on dirty eggshells. If these bacteria enter the egg in large quantities through the pores of the eggshell, eating such preserved eggs will be poisoned. When buying preserved eggs, it should be noted that the protein of preserved eggs is dark brown transparent body after peeling, which has certain toughness; Contaminated preserved eggs are light green, with poor toughness and easy loosening. Such preserved eggs must not be eaten.
Salmonella is the main bacterium that pollutes preserved eggs. After it enters the human body with preserved eggs, it causes inflammation on the intestinal trace membrane. After bacterial division, it will produce highly toxic endotoxin, which will cause poisoning symptoms.
Experiments have confirmed that Salmonella will die immediately at a high temperature of 100 degrees Celsius, at 70 degrees Celsius for 5 minutes, and at 60 degrees Celsius 15-30 minutes. Therefore, when eating suspicious preserved eggs, you can steam the shelled eggs at high temperature for about 5 minutes, and then you can eat them safely after cooling. The suitable temperature for the growth of Salmonella is 20℃-37℃, and the temperature in summer and autumn is just within this range, so people should pay special attention to prevent preserved egg poisoning.
Shrimp belongs to arthropod crustaceans, and there are many kinds, such as green shrimp, river shrimp, grass shrimp, crayfish, prawn, prawn, freshwater prawn, anglerfish, lobster and so on. Among them, prawn is a special product of our country, which is named because it is often sold in pairs in big sales. Shrimp live in warm waters and can live and breed in Bohai Bay in summer and autumn. In winter, shrimps have to migrate to the hot waters of the South Yellow Sea to escape the cold. Shrimp has poor mobility in winter and does not prey. Every March, shrimps scattered around the country begin to concentrate and swim to the north in droves. After two months' travel, they arrived in the shallow sea near the Bohai Sea and began to breed. Female shrimp are exhausted after a long journey, and most of them die after laying eggs. Only those who are strong can survive. The body structure of newly hatched shrimp has to undergo many changes, and it takes more than 20 molts to grow into a shrimp. Male shrimps mature that year, while female shrimps mature in the second year. Shrimp has slender tentacles twice the length of its body, which are used to sense the surrounding water. Its strong chest muscles are conducive to long-distance migration. The tail fan of the abdomen can be used to control the balance of the body and can also bounce back.
China has a vast sea area, many rivers and lakes, and is rich in sea shrimp and freshwater shrimp. Shrimp is a delicious and nutritious seafood, which can be used to make all kinds of delicious food. It has the reputation of "licorice" in dishes. There are prawns, prawns, prawns, mussels and lobsters. Green shrimp includes green shrimp, river shrimp, grass shrimp, crayfish and so on. There are salted shrimps such as white shrimps. No matter what kind of shrimp, it is rich in protein and has high nutritional value. Its meat is as soft and digestible as fish, but it has no fishy smell and bone spurs. At the same time, it is rich in minerals (such as calcium, phosphorus, iron and so on. ), and sea shrimp is also rich in iodine, which is very beneficial to human health. According to scientific analysis, protein accounts for about 16 ~ 20% of the edible part of shrimp.
Modern medical research has confirmed that shrimp has high nutritional value, which can enhance human immunity and sexual function, tonify kidney and strengthen yang, and resist premature aging. Eating fresh shrimp (fried, roasted and stewed) and warm wine can cure kidney deficiency, impotence, chills, fatigue, waist and knee pain and other symptoms. If there is little or no postpartum milk sweat, 500 grams of fresh shrimp, ground and hot rice wine, taken three times a day for several days, can promote lactation. Shrimp skin has sedative effect and is often used to treat neurasthenia and autonomic nerve dysfunction. Shrimp is a delicious food that can provide nutrition for the brain. Shrimp contains three important fatty acids, which can keep people focused for a long time.
There are many kinds of shrimp. Let's take Australian freshwater lobster as an example to talk about its culture process:
1, parent shrimp cultivation
Select 100 healthy prawns, with the size of 20-50g and the sex ratio of 1: 1 as parent prawns, and feed the selected parent prawns into a 6×8×l meter cement pond, which is covered with glass fiber reinforced plastic tiles and a heating system, and feed/kloc-0 every day. Red crayfish is bright red on the outside of the front, and its claws are longer than its body length; The claws of female shrimp are basically blue, and the length is less than the body length. The reproductive process of mature male shrimp is obviously rod-shaped at the base of the fifth foot; The reproductive pore of female shrimp is open at the base of the third foot. Put some cleaned and disinfected nets in the parent shrimp pond as the hidden objects of the parent shrimp, suck dirt and change water every day, and keep the light at12i:12d (12h light,12h dark).
2. Mating and spawning
In late April, the parent shrimps began to mate and lay eggs. The mating of red crayfish is soft shell mating. Before mating, the female shrimps should undergo reproductive molting, and within 12 hours after the male teacher produces sperm, the female shrimps begin to lay eggs. The eggs laid by the female shrimp are dark yellow after fertilization and attach to the empty stomach formed by the inward curling of the abdominal foot and tail fan. A shrimp with eggs weighing 48 grams has 326 eggs, a shrimp with high eggs has 44 1 egg, and a shrimp with low eggs has only 27 eggs.
3. Embryo development
The fertilized eggs of red crayfish are dark yellow, and gradually turn yellow-orange, red-orange and light gray with the development of embryos. The eggs of Procambarus clarkii were divided into four groups for comparative experiment of embryo development. The results showed that the embryo development of Procambarus clarkii eggs was extremely slow at 65438 09℃. At the temperature of 2 1-23℃, the hatching time is 4 1 day, and the young shrimp leave the mother body within 80 days. At 26℃, fertilized eggs hatch out of the membrane in 30 days, and young shrimps leave the mother body in 52 days. At 29-30℃, the membrane hatched within 25 days and separated from the mother body within 40 days.
4. Larvae culture
Larvae of red crayfish are hatched and collected, and then put into a soil pond for feeding. In the early stage of growth, larvae mainly feed on organic debris and unicellular algae such as Chlorella. Whether the water is rich in organic debris and unicellular algae is very important to improve the survival rate of crayfish larvae, and cannibalism will occur if the bait is insufficient. Through the anatomy of young shrimp, it is found that there are basically no zooplankton traces such as cladocera and copepods in the intestines and stomach of young shrimp, which is mainly due to the poor fluidity of young shrimp and the difficulty in obtaining zooplankton. After 7 weeks of rearing, the average length of larvae can reach 7.6 cm.
List of nutrients in shrimp
(According to 100g) Component Name Content Component Name Content Component Name Content
Edible part 86 Moisture (g) 78. 1 energy (kcal) 87
Energy (KJ) 364 protein (g) 16.4 Fat (g) 2.4
Prostitute title? G) 0 dietary fiber (g) 0 cholesterol (mg) 240
Ash (g) 3.9 Vitamin A (mg) 48 Carotene (mg) 0
Retinol (mg) 48 Thiamine (μ g) 0.04 Riboflavin (mg) 0.03
Nicotinic acid (mg) Vitamin C (mg) Vitamin E (ton) (mg) 5.33
α-ε0.06(β-γ)-ε0.43δ-ε4.84
Ca (mg) 325 P (mg) 186 K (mg) 329
Na (Mg) 133.8 Mg (Mg) 60 Fe (Mg) 4
Zinc (mg) 2.24 Selenium (mg) 29.65 Copper (mg) 0.64
Manganese (mg) 0.27 iodine (mg) 0
Component name content (mg) Component name content (mg) Component name content (mg)
Isoleucine 0 leucine 1573 lysine 1406
Sulfur amino acid (T) 492 methionine 492 cystine 0
Aromatic amino acid (T) 1283 phenylalanine 683 tyrosine 600
Threonine 694 tryptophan 0 valine 846
Arginine 1 155 histidine 390 alanine 1240
Aspartic acid 189 1 glutamic acid 3027 glycine 1064
Proline 72 1 serine 728
Nutritional analysis of shrimp
1. Shrimp is nutritious, soft and easy to digest, and it is an excellent food for people who are weak and need to be nursed back to health after illness;
2. Shrimp is rich in magnesium, which plays an important role in regulating heart activity and protecting cardiovascular system. It can reduce cholesterol content in blood, prevent arteriosclerosis, dilate coronary artery, and help prevent hypertension and myocardial infarction.
3. Shrimp has a strong breast enhancement effect and is rich in phosphorus and calcium, especially suitable for children and pregnant women;
Scientists at Osaka University in Japan have recently discovered that astaxanthin in shrimp helps to eliminate the "jet lag" caused by jet lag.