The relationship between chemistry and human health 1 Abstract: China has had it since ancient times? People eat for the sky? According to this statement, whether it is common people or emperors and nobles, whether it is primitive people who eat animals and drink blood or modern people who have plenty of food and clothing, 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 make themselves full, but also eat well, eat from the perspective of nutrition and rationally allocate food 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 weigh color, fragrance and taste? Where is the intake of macroelements and microelements better? What's the role? Wait a minute. This kind of problems related to health are all practical 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 that can be digested, absorbed and utilized by the 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 sugars and salts, 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, which can help chewing, soften food and move smoothly in the digestive tract; In addition, water can transform nutrients into solution, which can be absorbed by human body and enter blood and lymph through 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 living matter 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, not raw water and boiled water; Drink fresh boiled water, not water that has been left for too long; Drink water regularly, don't just think of drinking water when you are thirsty.
Protein is the material basis of life, which is closely linked with 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, and it is 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 supplied every day to keep the dynamic balance of protein in the body. The protein quality that a person needs to keep healthy depends on age, physiological characteristics and health status. The main sources of protein in Chinese people's diet are poultry, eggs, meat, fish, milk, beans and vegetables. The protein content of cereal food is not high, but it is also one of the main sources of protein as a staple food. In order to be healthy, we must ensure that every meal has a certain quality and quantity of protein, and pay attention to the reasonable collocation of things, and we can't be partial to food and overeat.
Fat is not only an essential substance for cell formation, transformation and growth, but also a nutrient with the highest calorie content. The body fat content changes with the nutritional status and the amount of activity. When hungry, energy consumption, body fat is decreasing, and the human body is gradually losing weight; 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 and protecting internal organs, and it can also help the 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 deficiency 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, the fat intake of middle-aged and elderly people with high living standards and little activity should be reduced appropriately.
Sugar is the main energy source of life activities. Except cellulose, all sugar substances are sources of heat energy. Sugar is a nutrient that generates heat energy, and each gram of glucose is oxidized in human body to generate 16.7KJ energy. The only source of energy needed in the nervous system is glucose in the blood. It keeps the human body warm, people often say? 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, etc. In animal foods, various dairy products and animal livers are also the main sources of sugar.
Sugar is not only food, but also can be used as seasoning to 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 have the opposite effect. Too much sugar intake in the diet can easily lead to diabetes, obesity, heart disease and high blood pressure. Therefore, for the health of the body, we should eat reasonably and take it in moderation.
Different from protein, fat and sugar, vitamins can neither generate heat nor participate in the composition of human cells and tissues, but they can regulate human metabolism, promote growth and development, get rid of some diseases, and improve the ability of human body to resist diseases. 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, leading to loss of appetite, indigestion and growth retardation; Lack of vitamin B2 can lead to oral ulcer, dermatitis, angular stomatitis, glossitis, cleft lip, keratitis, etc. Lack of vitamin B 12 will lead to megaloblastic anemia; Lack of vitamin C will lead to scurvy and reduce resistance; When vitamin D is lacking, children will suffer from rickets and adults will suffer from osteoporosis. Lack of vitamin E will lead to female infertility, abortion and muscular atrophy. Vitamins are both nutrients and medicines, which cannot be synthesized in human body (except vitamin D) and must be taken from food. There are great differences in the types and quantities of vitamins in various foods, and some vitamins are unstable in nature and easily destroyed in 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 it pays attention to a balanced diet and eats more fresh vegetables and fruits, it will generally not cause vitamin deficiency.
Among various elements in the human body, except 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 people's age. The fetal body weight contains 2 1.95g/k, while the adult body weight is 42.67g/k.. Inorganic salts are distributed in various tissues, most of which are bones and teeth. Among them, there are seven kinds of 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 they exist in very small amounts. Inorganic salt is an important nutrient element for human body, but it can't be synthesized in the body and can only be taken from food, drinking water and salt. Due to metabolism, the body loses a certain amount of inorganic salts every day, so human beings must get enough inorganic salts from food and drinks to maintain good health. If there is iron deficiency, it will lead to iron deficiency anemia and decreased immunity. You can eat iron-rich foods to supplement it, 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 may cause poisoning, especially trace elements.
Someone said? Is health eaten? Some people say? Is the disease from the mouth? All these can be summed up as that we should pay more attention to our daily eating habits. Especially in the present market where food varieties are complicated and pesticides and food additives are rampant, we can't slack off on eating. With the development of science and technology and the improvement of living standards, people can eat and afford more and more things, but there will be cases where they often prefer a certain food and don't touch other beneficial foods; There is also the situation of eating too much for one meal, but not eating at all, not paying attention to reasonable dining and balanced diet, which leads to a decline in health index. Are many diseases such as obesity and diabetes? Eat? So, 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 get 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, etc., and everyone should eat 300~500 grams a day; the second layer is vegetables and fruits, which should eat 400~500 grams a day respectively; The penultimate layer is fish, meat, poultry and eggs, which should be eaten125 ~ 200g every day (50g of fish and shrimp, 50 ~100g of livestock and poultry, and 25 ~ 50g of eggs); Milk and legumes occupy the fourth floor together, and eat milk and dairy products at100g and beans and bean products 50g every day; The top layer is grease, which does not exceed 25 grams per day.
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 ingested 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 standards and the acceleration of the pace of life, more and more people put forward newer and higher requirements for food. They want to make food more convenient, diverse, flavorful, nutritious and advanced. In order to meet these requirements, it is obviously not enough to just use our natural resources, so we gradually start to live without food additives, and diversified foods emerge one after another.
Keywords: food additives, food safety, nutrition and health
Text: the body is the capital of 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 talk about 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 the increasingly economical society, all kinds of unnatural new substances emerge one after another. While enjoying this beautiful life, human beings are also paying attention to things that are good or bad for their health. Especially in the daily necessities of human beings. ? Beautiful ham sausage, without any preservatives, is a well-known advertisement that reminds people of food safety. Food additives refer to chemical synthetic or natural substances added to food to improve food quality, color, smell and taste, 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. At present, most of the food additives used are chemically synthesized.
With 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 has been a lot of controversy between use and non-use. In fact, everything has two sides. Take aspartame, which is widely used in flavored yogurt, canned fruit, eight-treasure porridge, jelly, etc., as an example, it has a refreshing sweetness very similar to that of sucrose, and has no bitter aftertaste and metallic taste, so it is the sweetener whose sweetness is closest to that of 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 desired sweetness in application. 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. When mixed with essence, it has excellent synergistic effect, especially for acidic oranges, lemons, pomelo, etc., which can make the fragrance last and reduce the amount of aromatic. In addition, the protein component 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 in strong acid and alkali or when heated at high temperature to produce bitter phenylalanine or diketone, so it is not suitable for production temperature >: 150℃ baked goods and high-acid foods such as bread, biscuits and cakes. Because aspartame can be decomposed into phenylalanine, aspartic acid and methanol under the action of human gastrointestinal enzymes, it is not suitable for phenylketonuria patients. It has also been reported that a few people will be intolerant of aspartame, which may cause headaches, 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 can affect the consumption of body fat, resulting in fat accumulation and easy obesity; Eating too much sugar can 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 the lack of various nutrients. Besides, eating too much sugar may lead to diseases such as heart disease and high blood pressure. For young children, it may cause diseases such as dental caries, myopia, chondrosis and digestive tract. This also poses a great threat to people's health. Therefore, sometimes it is beneficial to use certain additives.
In fact, food additives are not as harmful to people's health as people think, and they 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 all kinds of animals or plants, and all kinds of fresh food. After plant harvesting or animal slaughter, if it is not processed in time or effectively preserved, it will often deteriorate. Appropriate 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 some foods do not use preservatives, they will cause a large number of pathogenic bacteria to breed and threaten people's health. Therefore, it is necessary for us to use preservatives properly. We don't have to force ourselves to use up the food in a short time for fear of deterioration. 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 composition of food is one of the most concerned and concerned things. Food should be nutritious, but food processing inevitably causes certain nutrient losses. When food is processed, adding some food nutritional fortifiers which belong to natural nutrients can greatly improve the nutritional value of food, which is of great significance for preventing malnutrition and nutritional deficiency, promoting nutritional balance and improving 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 varieties of food additives are used.
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