The relationship between chemistry and human health is 1 Abstract: Has China existed since ancient times? People eat for the sky? According to this view, whether it is common people or emperors and nobles, whether it is primitive people who eat animals and drink blood or well-fed modern people, food is an indispensable first-class important raw material for life at all stages of human evolution. In order to maintain life and health, people need to get enough food from the outside to get nutrition and energy. With the improvement of human civilization, people should not only satisfy themselves, but also eat well, eat from the perspective of nutrition and distribute food reasonably from the perspective of health. Chemistry can not only provide people with the means to increase food, but also help people understand the nutritional components of food and other related knowledge.
Keywords: nutrition and health chemistry
Introduction: With the improvement of living standards, people pay more and more attention to their own health problems. What should they eat? How to eat? How to balance color, fragrance and taste? Where is the intake of macro elements and trace elements better? What's the role? Wait a minute. This kind of health-related problems are all realistic problems in front of people. This paper mainly expounds some of the above problems.
In order to maintain life and health, people must take a certain amount of nutrients from food every day. These nutrients which can be digested, absorbed and utilized by human body are called nutrients, including water, protein, fat, sugar, vitamins and inorganic salts. They are called six life elements, among which protein, fat and sugar provide heat energy for people's lives and activities, also known as thermogenic nutrients.
Water is an important part of human body. Water not only often dissolves some soluble substances, such as sugar and salt, to form liquid, but also combines with protein and hydrophilic genes of sugar molecules to form bound water that cannot move freely. As a solvent, water is beneficial to digestion, can help chewing, make food soft and move smoothly in the digestive tract; In addition, water can transform nutrients into solutions, which are absorbed by the human body and enter the blood and lymph through the intestinal wall; A series of chemical reactions in cells are carried out in aqueous solution. Water is an environmental condition for the existence of life, and it is also a necessary substance for the chemical reaction of life itself. Water is of great significance for maintaining the normal physiological activities of organisms, so water is an indispensable substance for organisms and has important physiological functions.
When drinking water every day, drink more boiled water instead of raw water and boiled water; Drink fresh boiled water, not water that has been left for too long; Drink water regularly. Don't drink water just because you are thirsty.
Protein is the material basis of life, which is closely related to life and various forms of life activities. It can be said that there would be no life without protein. Growth, development, sports, heredity, reproduction and all other life activities are inseparable from protein. Protein in human tissues is continuously decomposed into amino acids, which are continuously synthesized and supplemented from amino acids provided by food and amino acids decomposed by tissue protein. Therefore, a certain amount of protein must be supplemented every day to keep the dynamic balance of protein in the body. Protein quality that a person needs to keep healthy depends on age, physiological characteristics and health status. The main sources of protein in China's diet are poultry, eggs, meat, fish, milk, beans and vegetables. The protein content of cereal is not high, but it is also one of the main sources of protein as a staple food. If you want to be healthy, you must ensure that every meal has a certain quality and quantity of protein, and pay attention to the reasonable collocation of things, not partial eclipse and overeating.
Fat is not only an essential substance for cell formation, transformation and growth, but also a nutrient with the highest calorie content. Body fat content changes with nutritional status and activity. When hungry, energy consumption, body fat reduction, the human body gradually thin; On the contrary, if you eat too much, your consumption will decrease, your body fat will increase, and your body will gradually become obese. The main sources of fat are cooking fat and the fat contained in food itself. Oil is very important in life movement, and it is the nutrient with the highest calorific value in human diet. It has the functions of providing energy, keeping body temperature, protecting internal organs, and helping digestion and absorption of fat-soluble vitamins. According to China's economic situation and eating habits, it is suggested that the supply of fat should account for 15%~25% of the total calories, which is equivalent to 30~50 grams of fat per person per day (including the fat contained in cooking and food). In order to prevent the lack of essential fatty acids, the content of essential fatty acids in diet should account for 1%~2% of total calories, and the intake of cholesterol should be below 300 mg. In addition, because high fat can cause obesity, hypertension and coronary heart disease, middle-aged and elderly people with high living standards and little activity should reduce their fat intake appropriately.
Sugar is the main energy source of life activities. Except cellulose, all sugars are sources of heat energy. Sugar is a nutrient that produces heat energy. Each gram of glucose is oxidized in human body to produce 16.7KJ of energy. The only source of energy needed by the nervous system is glucose in the blood. People often say that it can keep people warm? Is it warm when you are full? That's the truth. Using sugar to supply energy can save protein, so that protein can be mainly used for tissue construction and regeneration. Sugar in people's diet mainly comes from plants: grains, beans, potatoes, vegetables, fruits and so on. In animal foods, various dairy products and animal livers are also the main sources of sugar.
Sugar is not only a food, but also a condiment, which can adjust the flavor of food and increase appetite, so people especially like sweets. But sugar and sweets should not be eaten too much, especially for diabetics, which may be counterproductive. Eating too much sugar in the diet can easily lead to diabetes, obesity, heart disease and high blood pressure. Therefore, for the sake of health, we should eat reasonably and take it in moderation.
Unlike protein, fat and sugar, vitamins can neither generate heat nor participate in the composition of human cells and tissues, but can regulate human metabolism, promote growth and development, get rid of some diseases and improve human disease resistance. When the human body lacks vitamins, metabolism will be disordered and various vitamin deficiencies will occur. For example, the lack of vitamin A will lead to vitamin A deficiency, and its typical deficiency is dry eye and night blindness; Lack of vitamin B 1 will lead to neuritis and beriberi, resulting in loss of appetite, indigestion and growth retardation; Lack of vitamin B2 can lead to oral ulcer, dermatitis, angular stomatitis, glossitis, cleft lip and keratitis. Lack of vitamin B 12 will lead to megaloblastic anemia; Lack of vitamin c can lead to scurvy and reduce resistance; When vitamin D is deficient, children will suffer from rickets and adults will suffer from osteoporosis. Lack of vitamin E can lead to female infertility, abortion and muscle atrophy. Vitamins are both nutrients and drugs, which cannot be synthesized in the human body (except vitamin D) and must be taken from food. The types and quantities of vitamins in various foods vary greatly. Some vitamins are unstable in nature and are easily destroyed during food processing, storage and cooking. Therefore, it is very important for human beings to choose food reasonably and store, process and cook correctly. Because the human body does not need a lot of vitamins, as long as we pay attention to a balanced diet and eat more fresh vegetables and fruits, it will generally not cause vitamin deficiency.
Among the various elements in the human body, except for carbon, hydrogen, oxygen and nitrogen, which mainly appear in the form of organic compounds, all other elements are collectively called inorganic salts. Inorganic salts in the body only account for 4%~5% of human body weight, but they are indispensable substances to constitute human tissues and maintain normal physiological functions. The content of inorganic salts in human body increases with the increase of human age. Fetuses contain 265,438+0.95 g/k of inorganic salts per kilogram of body weight, while adults contain 42.67 g/k. Inorganic salts are distributed in various tissues, most of which are bones and teeth. There are seven major elements, namely calcium, magnesium, potassium, sodium, phosphorus, sulfur and chlorine. Other elements, such as iron, copper, iodine, zinc, manganese, cobalt, molybdenum, selenium, chromium, nickel, silicon, fluorine and vanadium, are called trace elements because their contents are very small. Inorganic salts are important nutrients for human body, but they can't be synthesized in the body and can only be taken from food, drinking water and salt. Because of metabolism, the human body loses a certain amount of inorganic salts every day, so human beings must get enough inorganic salts from food and drinks to maintain their health. If there is iron deficiency, it will lead to iron deficiency anemia and decreased immunity. You can eat foods rich in iron, such as animal liver, kidney, caviar, lean meat, potatoes, wheat bran, jujube and so on. In addition, we must pay attention to the amount of inorganic salts. Insufficient intake will cause deficiency, and excessive intake will cause poisoning, especially trace elements.
Someone said? Is health eaten? Someone said? Is the disease from the mouth? All these can be summed up in that we should pay more attention to our daily eating habits. Especially in the market where there are many kinds of food and pesticides and food additives are rampant, we can't be slack in eating. With the development of science and technology and the improvement of living standards, people can afford to eat more and more things, but there will also be cases where they often prefer a certain food and don't touch other beneficial foods; There is also a situation where you eat too much at a meal, but don't eat at all, and don't pay attention to reasonable meals and balanced diets, which leads to a decline in health index. Are there many diseases such as obesity and diabetes? Eat? Therefore, if you want to have a healthy body, you must establish a diet system that suits you.
All kinds of foods have different nutritional characteristics, and they must be reasonably matched to obtain comprehensive nutrition. China Nutrition Society designed it according to the dietary structure characteristics of China residents? China residents' balanced diet pagoda? The reasonable dietary structure of human beings is vividly pointed out: the bottom layer is plant food, including bread, cereal, rice, noodles and so on. And everyone should eat 300~500 grams every day; The second layer is vegetables and fruits, which should be eaten 400~500 grams each day; The penultimate layer is fish, meat, poultry and eggs, and you should eat 125 ~ 200g every day (50g of fish and shrimp, 50 ~ 100g of livestock and poultry meat, and 25 ~ 50g of eggs occupy the fourth layer together with milk and beans, and you should eat milk and dairy products 100g every day, and 50g of beans and bean products are the top layer.
In a word, biochemical reactions and life activities in human body depend on the participation of chemicals; And these chemicals are inseparable from nutrition; Nutrients are also taken in whole grains and animal meat; Vegetables and fruits. These three things complement each other. Only under the action of them can the human body grow healthily and prolong life.
Abstract: With the improvement of people's living standard and the acceleration of life rhythm, more and more people put forward newer and higher requirements for food. They want to make food more convenient, diverse, delicious, nutritious and advanced. In order to meet these requirements, it is obviously not enough to just use our natural resources, so we gradually began to live without food additives, and diversified foods emerged one after another.
Keywords: food additives, food safety, nutrition and health
Text: The body is the capital of the revolution. As the saying goes, the country is people-oriented, and the people take food as the sky; Only when you are in good health can you talk about ambition and Taoism. The strength of a country depends on its people. Only when the people are healthy can the country prosper and society progress. However, in an increasingly economic society, various unnatural new substances emerge one after another. While enjoying this beautiful life, human beings are also concerned about things that are beneficial or harmful to their health. Especially in human daily necessities. ? Beautiful ham sausage, without any preservatives? This well-known advertisement reminds people of food safety. Food additives refer to chemical synthetic or natural substances added to food to improve the quality, color, smell and taste of food, as well as the needs of anti-corrosion and processing technology. Food additives are non-nutritive substances, and the types of additives can be divided into natural food additives and chemically synthesized food additives according to their sources. Natural food additives are natural substances extracted from the metabolites of animals, plants or microorganisms. Chemically synthesized food additives are substances obtained by chemical means such as oxidation, reduction, condensation and polymerization of elements or compounds. Most of the food additives used at present are chemically synthesized.
With the emergence of food additives, people pay more and more attention to food safety. The use of food additives has also caused a lot of controversy, and there are also many controversies between use and non-use. In fact, everything has two sides. Take aspartame for example, it is widely used in flavored yogurt, canned fruit, eight-treasure porridge, jelly and so on. As an example, it has a refreshing sweetness very similar to sucrose, and has no bitter taste and metallic taste, so it is the sweetener with the sweetness closest to sucrose that has been successfully developed so far. The sweetness of aspartame is 200 times that of sucrose, and only a small amount is needed to achieve the ideal sweetness when applied. Therefore, using aspartame instead of sugar in food and beverage can obviously reduce calories and will not cause dental caries. When mixed with sucrose or other sweeteners, it has synergistic effect, such as adding 2% ~ 3% to saccharin, which can obviously cover up the bad taste of saccharin. After mixing with essence, it has excellent synergistic effect, especially for acidic oranges, lemons, grapefruit and so on. , can make the fragrance lasting and reduce the amount of fragrance. In addition, protein in aspartame can be naturally absorbed and decomposed by human body. Of course, there are advantages and disadvantages. Aspartame has poor stability to acid and heat, and it is easy to hydrolyze into bitter phenylalanine or diketone in strong acid and alkali or when heated at high temperature, so it is not suitable for producing baked food and high-acid food such as bread, biscuits and cakes with temperature >: 150℃. Aspartame is not suitable for patients with phenylketonuria because it can be decomposed into phenylalanine, aspartic acid and methanol under the action of human gastrointestinal enzymes. It has also been reported that a few people will be intolerant of aspartame, which may lead to headache, convulsions, nausea and allergic reactions. With these unfavorable factors, people's worries will follow. Some people may think that if aspartame is not added to jelly, eight-treasure porridge, canned fruit and other foods, it will not pose a threat to people's health. However, many problems are not as simple as people think. If aspartame is not used instead of sugar, the sugar in food will increase. Eating too much sugar will affect the consumption of body fat, resulting in fat accumulation and easy obesity; Eating too much sugar will also affect calcium metabolism; Eating too much sugar will make people feel full and have poor appetite, which will affect food intake and lead to various nutrient deficiencies. Besides, eating too much sugar may lead to diseases such as heart disease and high blood pressure. For young children, it may cause dental caries, myopia, rickets, digestive tract and other diseases. This also poses a great threat to people's health. Therefore, it is sometimes beneficial to use certain additives.
In fact, food additives are not as harmful to people's health as people think, and will bring people a lot of convenience. In addition to the aspartame mentioned above, there are many food additives that have certain uses. For example, preservatives, except for a few items (such as salt), food comes from various animals or plants, and all kinds of fresh food. Plants often go bad after harvest or animal slaughter if they are not treated in time or effectively preserved. Proper addition of some preservatives can prolong the shelf life of food. Many people think that preservatives in food will threaten people's health. However, if preservatives are not used in some foods, a large number of pathogenic bacteria will breed and threaten people's health. Therefore, it is necessary for us to use preservatives correctly. We don't have to force ourselves to run out of food in a short time for fear of spoilage. The color, aroma, taste and shape of food are also important indicators that people care about. After food processing, there will be fading, discoloration, flavor and texture changes. Proper use of colorants, color fixatives, bleaches, spices, emulsifiers and thickeners can obviously improve the sensory quality of food and meet the different needs of consumers. The nutritional content of food is one of the most concerned and concerned things. Food should be nutritious, but food processing will inevitably cause certain nutritional losses. In food processing, adding some food nutritional fortifiers belonging to natural nutrients can greatly improve the nutritional value of food, which is of great significance to prevent malnutrition and nutritional deficiency, promote nutritional balance and improve people's health. Of course, nothing can be used too much, even the best things will have an impact on health, and all kinds of food additives mentioned above are no exception, so we should use food additives moderately and appropriately. On the other hand, the use of food additives is a symbol of the progress of human diet culture. The more the food industry develops and people's living standards improve, the more kinds of food additives are used.
& gt& gt& gt More exciting next page? A small paper on the relationship between chemistry and human health?