I have always thought that the fermentation process of steamed bread is amazing. Shandong people's savvy talent for steamed stuffed buns has increased by 5%.
I have seen grandma's, grandma's and mom's steamed buns for many years, and I am making steamed buns for my children for the first time. Mainly the recent food safety is a bit too worrying. If there is a nuclear war in the world, China people will definitely hold more meetings than foreigners, because our talents in China are "lead stomachs" ~ ~
It's too uncomfortable to buy it outside. I'm afraid the raw material is leftover steamed bread and I'm afraid of catching a glimpse of white things. So do it yourself.
The process of making more assured steamed bread is like this. Beware of rice eaters!
1. Put noodles. Step 2 pour water. 3. Knead the noodles. 4. Have a rest. 5. Make steamed bread. 6. Have a rest again. 7. Put water in the steamer and light it. 8. Throw away the steamed bread when the water boils. Take it out in 9.20 minutes! ! ! Just finished! ! ! !
The process of 4 and 6 is meaningful! This means ~ ~ ~ this depth!
According to my current understanding of scientific knowledge, there will be natural fungi in cereals without oxygen, and the metabolic process of fungi will affect cereals. This process is called fermentation, scientific name is fermentation, and English name is fermentation. This is why steamed bread is soft and big.
The noodles that have just been reconciled will not have the effect of fungi immediately, so if you want to make the steamed bread soft. Bacteria must be added. So there are three commonly used treatments. 1. Old noodles (more difficult) 2. Add yeast 3. Spontaneous noodles.
2. Chemical scientific papers
Chemistry is a natural science and a compulsory course in middle school. It is the result of scientific research and practice of countless Chinese and foreign chemists throughout the ages. It compiles some basic chemical concepts, basic theories, knowledge of elemental compounds, basic types of chemical reactions, classification of inorganic substances and their relationships. It is full of the principles and contents of materialist dialectics, and introduces the excellent qualities of many scientists, the scientific attitude of seeking truth from facts and the rigorous style of study. Chemistry plays an important role in industrial and agricultural production, national defense and modernization of science and technology, and people can't live without chemistry.
Chemistry is an experimental science. Through the study of chemistry class, we can master some basic skills of chemical experiments and learn the ability to do experiments by hands, so as to lay the foundation for future scientific experiments.
Therefore, through the study of junior middle school chemistry class, junior three students can not only learn the basic knowledge of junior middle school chemistry, but also be educated by dialectical materialism, patriotic thoughts and behaviors of Chinese and foreign chemists, scientific attitude of continuous exploration and innovation, and rigorous study style. They can also improve their observation ability, thinking ability, experimental ability and self-study ability, and lay a good foundation for studying senior high school chemistry and other technologies in the future.
Please finish your homework independently. Thank you. The format should be the same as mine. With keywords, the conclusion is the most important.
The conclusion is the final summary of the whole article. The conclusion is not a necessary part of a scientific paper. Mainly to answer "what" (what). It should be based on the phenomena, data and analysis obtained from the experiment or investigation in this paper, so as to point out completely, accurately and concisely: first, the principle and universality revealed by the results obtained by the research object from the investigation or experiment; Second, whether there are any abnormalities found in the study or problems that are difficult to explain and solve in this paper; 3. Similarities and differences with previously published research work (including others or the author himself); Fourthly, the theoretical and practical significance and value of this paper; Fifth, suggestions for further research on this topic.
3.8 References
It reflects the scientific basis of the manuscript and the author's respect for other people's research results, and provides readers with the sources of relevant materials cited in the paper, or provides detailed words of relevant contents mentioned in the paper but not developed in order to save space and facilitate narration. References contained in the paper should be limited to those publications read by the author himself and cited in the paper, or other relevant files, including patents and other documents.
3. Essays on Chemistry, Life and Learning
Life is rich and colorful. Inadvertently, people often encounter some perfect combination of chemistry and life. But people seldom pay attention to its subtlety and interest.
Everyone must be familiar with "salted fish". But why can fish be preserved for a long time without corrosion and deterioration with a little salt? The key is salt. The cause of food corruption is due to the action of microorganisms and bacteria. As long as the growth of biological bacteria is controlled, food spoilage can be prevented. The main component of salt is sodium chloride, which is electrolyte, and the osmotic pressure of its saturated solution is greater than that of non-electrolyte solution (protein solution in microbial and bacterial cells). When a solution with high osmotic pressure and a solution with low osmotic pressure are separated by a semi-permeable membrane (such as a cell membrane), solvent molecules will permeate from the side with low osmotic pressure to the side with high osmotic pressure. That is, in the presence of salt solution, water molecules in microbial bacterial cells will continue to enter the salt solution, leading to cell drying and death, thus playing an anti-corrosion role. Sodium chloride not only created a special case of "Immortality of the Dead Sea", but also performed well in the field of anticorrosion.
Water is the source of life, and the hardness of water has a great relationship with human health. Ca2+ and Mg2+ in high hardness water can combine with SO42-, which makes the water bitter and astringent, and also makes people's gastrointestinal function disorder, resulting in temporary waist edema, excessive exhaust and diarrhea, which is the secret of "acclimatization".
What is the relationship between chemistry and life? I want to say: chemistry is indispensable for a high-quality life. What, you don't believe me? I'll accompany you to Mrs. Wang's house!
As it happens, Mrs. Wang is cooking in the kitchen. I saw Mrs. Wang turn on the liquefied gas switch, and in less than 10 minutes, a plate of delicious fried cabbage was ready. Adding iodized salt to this delicious dish is not only delicious, but also has the function of health care and disease prevention! Mrs. Wang fried a plate of three layers of meat and made steamed bread, and then yeast came in handy. You see, steamed bread tastes particularly soft after fermentation. After a while, Uncle Wang came to eat steamed bread. It's strange that Uncle Wang wears glasses. It's foggy in the cupboard. Why don't lenses blur? It turned out that he used an antifogging agent containing carboxymethyl fiber to turn the hydrophobic surface of the original lens into a hydrophilic surface, so that it was not easy to condense water droplets. Alas! There are still a few steamed buns made by Mrs. Wang today. Will it be bad to keep it? It doesn't matter. Mrs. Wang has her own clever tricks. She made carbon dioxide from baking soda and 36 degrees white wax and put it in a bottle with steamed bread. In this way, the steamed bread treated with carbon dioxide, if put on 1~3 days, still keeps its fragrance and does not deteriorate. After dinner, it's time to wash the dishes, but the dishes with three layers of meat just now are greasy and not easy to wash! This is Mrs. Wang's usual practice. As long as it is washed with hot water with alkali, the oil stain can be well washed off. What is Mrs. Wang doing after washing the dishes? It turns out that she is using a disinfection cabinet to disinfect the tableware! This kind of disinfection cabinet is made according to whether ozone is produced when oxygen is discharged under high pressure. Ozone is a strong oxidant, which can effectively kill bacteria and prevent bacteria from multiplying, thus ensuring people's health.
Chemistry is closely related to life, so we should try our best to learn chemistry well.
4. Why are steamed bread moldy? Scientific papers 100
Any food will go bad after being left at room temperature for a period of time. Some are moldy and caked, some are rotten and smelly, and some are sour. ...
There are three main reasons for food deterioration:
1, microorganism. There are microorganisms everywhere in the environment, and food is easily contaminated by microorganisms in the process of production, processing, transportation, storage and sales. As long as the temperature is appropriate, microorganisms will grow and reproduce, decompose nutrients in food and meet their own needs. At this time, the protein in food will be destroyed, the food will become smelly and sour, lose its original toughness and elasticity, and the color will also change.
2, the role of enzymes. There are many kinds of enzymes in animal food. Under the action of enzymes, the nutrients in food are broken down into a variety of low-grade products. Usually rice turns sour and fruit rots, that is, carbohydrates are decomposed and fermented by enzymes.
3. Chemical reaction of food. Oils and fats are easily oxidized, resulting in a series of chemical reactions. Oil has a strange smell after oxidation, such as fat turning from white to yellow.
Deteriorated food not only changes in appearance, but also loses the color, fragrance and taste quality of the original food, and its nutritional value will also decrease, and it will also contain corresponding toxins harmful to human health.
5. Chemical scientific papers
Chemistry is a natural science and a compulsory course in middle school. It is the result of the research and practice of countless Chinese and foreign chemists in the field of chemical science. Some basic concepts that have been programmed into chemistry are 62616964757a68696416fe4b893e5b19E31333263665. It is full of the principles and contents of materialist dialectics, and introduces the excellent qualities of many scientists, the scientific attitude of seeking truth from facts and the rigorous style of study.
Chemistry plays an important role in industrial and agricultural production, national defense and modernization of science and technology, and people can't live without chemistry. Chemistry is an experimental science. Through the study of chemistry class, we can master some basic skills of chemical experiments and learn the ability to do experiments by hands, so as to lay the foundation for future scientific experiments.
Therefore, through the study of junior middle school chemistry class, junior three students can not only learn the basic knowledge of junior middle school chemistry, but also be educated by dialectical materialism, patriotic thoughts and behaviors of Chinese and foreign chemists, scientific attitude of continuous exploration and innovation, and rigorous study style. They can also improve their observation ability, thinking ability, experimental ability and self-study ability, and lay a good foundation for studying senior high school chemistry and other technologies in the future. Please finish your homework independently. Thank you. The answer supplement should be in the same format as mine, with keywords. The most important conclusion is the final summary of the whole article.
The conclusion is not a necessary part of a scientific paper. Mainly to answer "what" (what).
It should be based on the phenomena, data and analysis obtained from the experiment or investigation in this paper, so as to point out completely, accurately and concisely: first, the principle and universality revealed by the results obtained by the research object from the investigation or experiment; Second, whether there are any abnormalities found in the study or problems that are difficult to explain and solve in this paper; 3. Similarities and differences with previously published research work (including others or the author himself); Fourthly, the theoretical and practical significance and value of this paper; Fifth, suggestions for further research on this topic. 3.8 References It reflects the scientific basis of the manuscript and the author's respect for other people's research results, and provides readers with the sources of relevant materials cited in the paper, or provides detailed words of relevant contents mentioned in the paper but not developed in order to save space and facilitate narration.
References contained in the paper should be limited to those publications read by the author himself and cited in the paper, or other relevant files, including patents and other documents.
6. Kneel for a few small ninth grade chemistry papers. Which kind-hearted person can help? Thank you very much.
As soon as we open the door of chemistry and enter the students' field of vision, it reflects the omnipresence of chemistry in human daily life. Interest is the best teacher in learning. As soon as the door of chemistry is opened, students will truly experience that the content of chemistry learning and research is lively, interesting and colorful; Is charming, charming. As soon as students step into the hall of chemistry, they will realize that learning should be linked with life and production practice. In teaching, vivid examples are used to guide students to understand the role of chemistry in helping human beings improve their quality of life, so that students can feel that learning chemistry is very useful and meaningful.
Chemistry can help people do useful things. Food, clothing, housing and transportation, chemistry is everywhere. Chemistry is indispensable for a high-quality life. Just cook in the kitchen, turn on the liquefied gas switch, and in less than 10 minutes, a plate of delicious fried cabbage will be ready. Adding iodine-containing salt to this delicious dish is not only delicious, but also has the function of health care and disease prevention. Put some soda in the steamed bread. The steamed bread is big and white and delicious. The leftover steamed bread is made of baking soda and white vinegar into carbon dioxide, and the carbon dioxide and steamed bread are put together in a bottle. In this way, the steamed bread treated with carbon dioxide, if put on 1~3 days, still keeps its fragrance and does not deteriorate. The rice wine brewed at home turned sour, and many people could do nothing about it. It's actually quite simple. Sour rice wine will not be sour as long as a little edible alkali is added.
7. Write a short article about chemistry
The hole in the steamed bread biscuit Have you visited the biscuit factory? Only a dough the size of a nickel has been sent to the oven to turn over. After coming out, the volume is greatly increased and it becomes loose and fragile. When a cake is opened, you can see that it is full of holes like a honeycomb.
Bread and steamed bread are also full of small holes. Fried dough sticks, as thick as a pen before frying, expand rapidly in the oil pan and become thicker than the clothesline! Who cast this magic? A magician is a kind of yeast, or a chemical substance.
You must remember that when brewing wine, yeast eats sugar converted from starch and spits out alcohol and carbon dioxide. The same is true of making steamed bread.
There is also flour, and there are many yeasts living in the "old noodles". As long as the temperature is right, they multiply rapidly in wet flour.
The alcohol they spit out gives steamed bread a mellow fragrance, and the released carbon dioxide gas occupies the space in the wet dough and supports the small holes. When steaming steamed bread, small bubbles expand further when heated, and large pores bulge out in flour.
Protein-gluten in flour solidifies when heated and becomes the "wall" of pores, completely surrounding carbon dioxide. Finally, the wall broke and carbon dioxide escaped, leaving countless small holes in the steamed bread.
When making cookies, cakes and bread, another baking powder is often used. This baking powder has nothing to do with yeast, but it is actually a chemical loosening agent.
It contains two kinds of chemical powders-sodium bicarbonate and sodium dihydrogen phosphate, which change chemically when put into wet noodles, releasing carbon dioxide gas, causing many small holes in food. The dough sticks are pre-kneaded with edible alkali and alum.
The "one alkali, two alums and three salts" mentioned by the chef of the breakfast shop means that one or two edible alkalis, two alums and three salts are added to every seven Jin of flour, and then the dough is made into fried dough sticks. These three chemical actions have their own functions: salt makes noodles salty and elastic, and alum is potassium aluminum sulfate, which is acidic. In the boiling oil pan, it reacts with alkali to generate a large number of carbon dioxide bubbles, which expand rapidly when heated, making the fried dough sticks expand rapidly.
One or two basic vegetables and two or two alums can produce about 14 liter of carbon dioxide gas. When the oil is boiled at a high temperature of more than 200 degrees, its volume expands by more than two times, so the newly fried fritters are loose and porous. More interestingly, bubbles in beer and soda can also be produced by the reaction of alkali and acidic chemicals.
The reason is the same as before. Do you want to make homemade soda? It's simple. Fill a thick-walled soda bottle or beer bottle with cold boiled water with sugar or orange juice in advance. Don't fill it.
Then, quickly pour 2 grams of edible alkali powder and 2 grams of citric acid into the bottle, cover the cork tightly, tie it tightly with iron wire, then wrap the bottle with a towel and shake it a few times. The carbon dioxide gas produced by the reaction can't escape from the bottle, so we have to stay in the bottle and live in soda for the time being.
Of course, there is no need to bother to produce soda and wine in the factory, but directly pressurize carbon dioxide gas to make it more soluble in water. When you open the bottle cap of soda, the carbon dioxide gas dissolved in soda under high pressure will be released and emerge from the water.
If you drink soda for a short time, bubbles will appear in your stomach. This is because the carbon dioxide in soda will "escape" when it is heated in your stomach. It takes away a part of your body's heat, so drinking soda in summer can reduce your fever. Part of carbon dioxide is dissolved in water to produce carbonic acid, which is a weak acid. Weak acid can be very mild to the stomach and help digestion.
The secret of color-changing glasses Many car drivers often wear a pair of black glasses when driving. This pair of black glasses can protect your eyes from strong light when driving in the sun or snow for a long time.
However, when the car suddenly drives from bright to dark, wearing black glasses becomes a burden. It's really inconvenient to wear it for a while and take it for a while.
Is there any good way to relieve the driver's distress? Yes Wear color-changing glasses.
In the sun, it is a pair of black sunglasses, and thick black glass lenses block the dazzling light. In a room with soft light, it becomes as transparent and colorless as ordinary glass.
The secret of color-changing glasses is in the glass. This special glass is called photochromic glass.
In the manufacturing process, photosensitive substances such as silver chloride, Australian silver halide and a small amount of copper oxide catalyst are pre-doped. Glasses from colorless to light gray, dark brown, and then from black glasses back to audio-visual glasses, are the magic of silver halide. "
In the glass of color-changing glasses, there is a change process very similar to the exposure imaging of photosensitive film. Silver halide is decomposed by light and becomes many black silver particles, which are evenly distributed in the glass, so the glass lens appears dim and blocks the passage of light. These are black glasses.
However, unlike the photo film, the silver atoms and halogen atoms produced by the decomposition of silver halide are still closely combined. When we return to a slightly dark place, with the promotion of copper oxide catalyst, silver and halogen recombine to form silver halide, and the glass lens becomes transparent again.
Silver halide is resident in glass, and the reaction of decomposition and combination goes on endlessly. Photographic film and paper can only be used once, but color-changing glasses can always be used.
Color-changing glasses can not only darken and brighten with the light intensity, but also absorb ultraviolet rays harmful to human eyes, which is really the top grade in glasses. If all the windows are replaced with light-colored glass, the sun will not shine in the room on a sunny day; On cloudy days or in the morning and evening, the outdoor light is not blocked and the room is still bright.
It's like hanging an automatic sunshade on the window. In some high-end hotels and restaurants, color-changing glass has been installed.
This photochromic glass is installed in the cab of the car and the window of the tour bus. You don't even need to wear color-changing glasses in direct sunlight. Always keep soft light in the car to avoid glare and exposure of the sun. How happy everyone should be! How happy I am to wash away the stains and put on new clothes. "Pa, the ink bottle spilled on the ground, and the ink splashed on the new clothes. How to clean it? Ink, fruit juice, engine oil and ballpoint pen oil are inevitably stained on our clothes.
If you put all the stains in the washtub, sometimes it will not be cleaned, but will enlarge the stains. The chemical composition of stains is different, and the temper is also very different.
Sweaty vest
8. The principle of yeast steamed bread
Acid yeast can grow in the range of pH 3-7.5, and the optimum pH is pH4.5-5.0.
Yeast powder mainly uses medium flour and high flour to make bread or steamed bread. Its main function is to expand gluten strength, increase dough volume and make the finished product taste tough. Nutritional analysis of yeast: 1. Yeast powder is rich in vitamin B group. Vegetarians often lack B 1, B2 and B 12, which can provide complete satisfaction in yeast powder. 2. Add yeast into the dough. At the temperature of 25~30 degrees, the yeast grows by using sucrose, glucose, fructose and maltose converted from amylase in the dough itself, and decomposes some sugar into carbon dioxide and alcohol, so that the dough immediately expands and initiates. Finally, a large number of empty bubbles are formed in steamed bread and other foods, which are loose, soft and fragrant.
It's sour because you've been cooking steamed bread for too long.
9. A short article about chemistry and life
In our life, there is the shadow of chemistry almost everywhere. First of all, we can't do without chemistry. For the simplest example, when people eat and drink water, chemical reactions will inevitably occur in every process, from food entering the test tube and stomach, to being digested by gastric acid, absorbed by capillaries and finally excreted.
Besides, people eat food because it is nutritious, and where does nutrition come from? Plants are exposed to sunlight, and then through photosynthesis, water and inorganic salts become starch and are stored in grains. Today, when grain grows from the ground, nutrient solution and fertilizer are essential. The use of various nitrogen fertilizers, phosphate fertilizers, potash fertilizers and compound fertilizers has improved the yield and quality of grain. Pesticides are also essential in pest season. Coupled with the drugs that people use to treat diseases, these are the benefits that chemistry brings to mankind.
Some common sense in life is also closely related to chemistry. For example, eating fruit can relieve alcohol. This is because fruit contains organic acids, and the main component of wine is ethanol, and organic acids can interact with ethanol to form esters, thus achieving the purpose of hangover. Also, when you open the bottle of carbonated drinks, bubbles will come out. The reason is that people often make soda water with baking soda (sodium bicarbonate) and citric acid. When baking soda and citric acid are mixed in water, they will react with each other to produce carbon dioxide gas, but the bottle has been blocked and carbon dioxide is forced to stay in the water. When the cork is opened, the external pressure is small, and carbon dioxide gas escapes from the water, forming a scene of bubbles churning.