Cellulose is the main structural component of plant cell wall, which is usually combined with hemicellulose, pectin and lignin, and its combination mode and degree have great influence on the texture of plant-derived food. However, the changes of plant texture in mature and post-mature stages are caused by the changes of pectin substances. Cellulase does not exist in human digestive tract, and cellulose is an important dietary fiber. The most widely distributed and abundant polysaccharide in nature.
Chinese name: cellulose mbth: chemical formula of cellulose: (C6H 10O5)n molecular weight: 50000 ~ 2500000 properties, preparation method, function, physiological function, dietary fiber, intake, content determination, content, drugs, related contents, specific introduction, polymer cellulose, lignin fiber, building fiber, cellulose ether. Methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, journal name, attribute 1. Soluble cellulose at room temperature, cellulose is insoluble in neither water nor common organic solvents, such as ethanol, ether, acetone and benzene. It is also insoluble in dilute alkali solution. So it is relatively stable at room temperature, because there are hydrogen bonds between cellulose molecules. Cellulose is insoluble in water and organic solvents such as ethanol and diethyl ether, but soluble in copper ammonia Cu(NH3) 4 (OH) 2 solution and copper ethylenediamine [NH 2 CH 2 CH 2 NH 2 ]Cu(OH) 2 solution. 2. Cellulose hydrolysis Under certain conditions, cellulose reacts with water. During the reaction, the oxygen bridge is broken, and water molecules are added at the same time, and cellulose changes from long-chain molecules to short-chain molecules until the oxygen bridge is completely broken and becomes glucose. 3. Cellulose oxidizes cellulose and oxidant to produce a series of substances with different structures from original cellulose. This reaction process is called cellulose oxidation. The base ring of cellulose macromolecules is a macromolecular polysaccharide composed of D- glucose with β- 1 4 glycosidic bond, and its chemical composition contains 44.44% carbon, 6. 17% hydrogen and 49.39% oxygen. Due to different sources, the number of glucose residues in cellulose molecules, that is, the degree of polymerization (DP), is in a wide range. It is the main component of the cell wall of vascular plants, lichens and some algae. Cellulose was also found in the capsules of Acetobacter and Chordata, and cotton was of high purity (98%). The so-called α -cellulose refers to the part that can not be extracted from the original cell wall intact cellulose standard sample with 17.5%NaOH. β -cellulose and γ -cellulose are cellulose corresponding to hemicellulose. Although α -cellulose is usually crystalline cellulose, β -cellulose and γ -cellulose contain various polysaccharides besides cellulose. Cellulose in the cell wall forms microfibers. The width is 10-30 nm and the length is several microns. Through X-ray diffraction and negative staining (negative staining), according to the observation of electron microscope, the crystalline parts of chain molecules arranged in parallel constitute basic microfibers with a width of 3-4 nanometers. It is speculated that these alkaline microfibers together constitute microfibers. Cellulose can be dissolved in Schwitzer reagent or concentrated sulfuric acid. Although it is not easy to hydrolyze with acid, dilute acid or cellulase can make cellulose produce D- glucose, cellobiose and oligosaccharide. Cellulose synthase (UDP forming EC 2.4.1.12) transfers glucoside from UDP glucose primer in Acetobacter to synthesize cellulose. Standard samples of granular enzymes with the same activity have been obtained in higher plants. This enzyme usually uses GDP glucose (GDP formation) EC 2.4. 1.29), and glucose is mixed with β- 1, 3 bond when it is transferred from UDP. The formation position of microfibers and the mechanism of controlling cellulose arrangement are not clear. On the other hand, as far as cellulose decomposition is concerned, it is estimated that when the primary cell wall is stretched and grown, a part of microfibers will be decomposed and become soluble due to the action of cellulase. Water can cause limited swelling of cellulose, and some aqueous solutions of acid, alkali and salt can penetrate into the fiber crystallization area, resulting in unlimited swelling and dissolution of cellulose. When cellulose is heated to about 150℃, it will not change obviously, and it will gradually coke due to dehydration when it exceeds this temperature. Cellulose reacts with concentrated inorganic acid to produce glucose and so on. Alkaline cellulose is generated by concentrated caustic solution, and oxidized cellulose is generated by strong oxidant. 4. Flexible cellulose is both flexible and rigid, because: (1) cellulose molecules are polar and the interaction between molecular chains is strong; (2) The six-membered pyran ring structure in cellulose makes internal rotation difficult; (3) The intramolecular and intermolecular hydrogen bonds of cellulose can be formed, especially intramolecular hydrogen bonds, which make the glycosidic bond unable to rotate, thus greatly increasing its rigidity. Method 1: Cellulose is the most abundant natural polymer compound in the world, and its raw materials come from wood, cotton, cotton linter, wheat straw, rice straw, reed, hemp, mulberry bark, paper mulberry bark and bagasse. Due to the shortage of forest resources in China, 70% of cellulose raw materials come from non-wood resources. The average cellulose content of softwood and hardwood in China is about 43-45%. The average cellulose content of grass stems is about 40%. The industrial preparation method of cellulose is to cook plant raw materials with sulfite solution or alkali solution, mainly to remove lignin, which is called sulfite method and alkali method respectively. The obtained materials are called sulfite pulp and alkaline pulp. Then the residual lignin is further removed by bleaching, and the obtained bleached pulp can be used for papermaking. After further removal of hemicellulose, it can be used as raw material of cellulose derivatives. Production method 2: Pulverize fiber plant raw materials and inorganic acid to make α-cellulose, then depolymerize the cellulose part through treatment, remove the amorphous part and purify. Production method 3: the selected industrial wood pulp board is defibered, then sent to a reaction kettle filled with 1% ~ 10% hydrochloric acid (the dosage is 5% ~ 10%), heated and hydrolyzed at 90 ~ 100℃ for 0.5 ~ 2h, and then sent to a neutralization tank after cooling. Method 4: Cellulose made of wood pulp or cotton pulp. It is refined after bleaching and mechanical dispersion. Functional cellulose is the oldest and richest natural polymer on the earth, which is inexhaustible and the most precious natural renewable resource for human beings. Cellulose chemistry and industry started from 160 years ago, which is the main research object in the birth and development period of polymer chemistry. The research results of cellulose and its derivatives have made great contributions to the establishment, development and enrichment of polymer physical chemistry. Physiological Function There is no β -glucosidase in human body, so cellulose cannot be decomposed and utilized. Cellulose can absorb a lot of water, increase the amount of feces, promote intestinal peristalsis, accelerate fecal excretion, shorten the residence time of carcinogens in the intestine, and reduce the adverse effects on the intestine, thus preventing the occurrence of intestinal cancer. Dietary fiber The cellulose in human diet mainly exists in vegetables and miscellaneous grains. Although it cannot be digested and absorbed, it can promote intestinal peristalsis and facilitate fecal excretion. Herbivores rely on microorganisms in their digestive tract to decompose cellulose so that it can be absorbed and utilized. Dietary fibres includes crude fiber, semi-crude fiber and lignin. Dietary fibres is an indigestible substance. In the past, it was considered as "waste". 20 13 years is considered to play an important role in protecting human health and prolonging life. So it is called the seventh nutrient. Among dietary fibers, various high-purity dietary fibers are extracted from natural foods (konjac, oats, buckwheat, apples, cacti, carrots, etc.). ) generally used. The main functions of dietary fiber are: the molecular structure of cellulose is1; Dietary fiber for treating diabetes can improve the sensitivity of insulin receptor and improve the utilization rate of insulin; Dietary fiber can wrap the sugar in food and make it gradually absorbed, which has the function of balancing postprandial blood sugar, thus regulating the blood sugar level of diabetic patients and treating diabetes. 2. Prevention and treatment of coronary heart disease The increase of serum cholesterol content will lead to coronary heart disease. The excretion of cholesterol and cholic acid is closely related to dietary fiber. Dietary fiber can be combined with cholic acid, so that cholic acid can be excreted quickly. At the same time, the combination of dietary fiber and cholic acid will promote the conversion of cholesterol into cholic acid, thus reducing the cholesterol level. 3, antihypertensive effect Dietary fiber can absorb ions and exchange with sodium and potassium ions in the intestine, thereby reducing the proportion of sodium and potassium in the blood, thus lowering blood pressure. 4. Anti-cancer effect Since the 1970s, there have been more and more reports about the anti-cancer effect of dietary fiber, especially the relationship between dietary fiber and digestive tract cancer. An early survey in India showed that people living in northern India consumed much more dietary fiber than southerners, and the incidence of colon cancer was much lower than that of southerners. According to this survey, scientists have done more in-depth research and found that dietary fiber can prevent and treat colon cancer for the following reasons: some saprophytic bacteria in the colon can produce carcinogens, while some beneficial microorganisms in the intestine can use dietary fiber to produce short-chain fatty acids, which can inhibit the growth of saprophytic bacteria; Cholic acid and cholic acid in bile can be metabolized by bacteria into carcinogens and mutagens of cells, and dietary fiber can be combined with cholic acid and excreted to prevent the production of these carcinogens; Dietary fiber can promote intestinal peristalsis, increase fecal volume and shorten emptying time, thus reducing the chance of carcinogens in food contacting colon; Beneficial bacteria in the intestine can use dietary fiber to produce butyric acid, which can inhibit the growth and proliferation of tumor cells, induce tumor cells to transform into normal cells, and control the expression of oncogenes. 5, weight loss treatment of obesity dietary fiber replaces the number of certain nutrients in food, reducing the total intake of food. Dietary fiber promotes the secretion of saliva and digestive juice, fills the stomach, absorbs water and swells, which can produce satiety and inhibit the desire to eat. Dietary fiber is combined with some fatty acids, so that fatty acids cannot be absorbed when passing through the digestive tract, thus reducing the absorption rate of fat. 6. Dietary fiber for constipation has strong water holding capacity, and its water absorption rate is as high as 10 times. After absorbing water, the volume of intestinal contents is increased, which makes the stool loose and soft, and it will be smoother and more labor-saving when passing through the intestine. At the same time, dietary fiber, as a foreign body in the intestine, can contract and peristalsis the intestine, accelerate defecation and play a role in treating constipation. Vegetables are rich in cellulose. Foods that do not contain cellulose include: chicken, duck, fish, meat, eggs and so on. Foods containing a lot of cellulose include coarse grains, bran, vegetables and beans, among which cotton has the highest content, reaching 98%. Therefore, it is suggested that diabetics eat more foods rich in cellulose, such as beans and fresh vegetables. At present, most domestic plant fiber foods are made of rice bran, bran, distiller's grains, beet chips, pumpkins, corn husks, seaweed, etc., which have a certain effect on lowering blood sugar and blood lipid. Content determination Cellulose is not fiber, they are two concepts. The cellulose content was determined by a cellulose analyzer. Crude fiber is generally determined, and dietary fiber is also determined in food. Although the content of cellulose can't be absorbed by human body, it has a good effect of clearing intestine, and it is a healthy food suitable for IBS patients. The cellulose content of common foods is as follows: food bran rich in cellulose: 365,438+0% and grain: 4-65,438+00%, which are arranged from big to small as wheat, barley, corn, buckwheat flour, coix seed flour, sorghum rice and black rice. Cereals: 8-9%; Oatmeal: 5-6% potatoes, sweet potatoes and other potatoes have a cellulose content of about 3%. Beans: 6- 15%, in descending order: soybean, mung bean, broad bean, kidney bean, pea, black bean, adzuki bean and mung bean. Generally speaking, the finer the processing, the less the cellulose content, regardless of grain, potato or bean. Vegetables: The content of bamboo shoots is the highest, the cellulose content of dried bamboo shoots reaches 30-40%, and the pepper exceeds 40%. The rest have higher cellulose content: bracken, cauliflower, spinach, pumpkin, Chinese cabbage and rape. Fungi (dry): the cellulose content is the highest, of which the cellulose content of Tricholoma matsutake is close to 50%, and the order of more than 30% is: mushroom, tremella and auricularia. In addition, the cellulose content of laver is also very high, reaching 20%. Nuts: 3- 14%. /kloc-more than 0/0% are: black sesame, pine nuts and almonds; Below 10% are white sesame, walnut, hazelnut, walnut, sunflower seed, watermelon seed and peanut kernel. Fruits: Dry red fruits are the most abundant, and the cellulose content is close to 50%, followed by dried mulberries, cherries, wild jujubes, dates, pomegranates, apples and pears. All kinds of meat, eggs, dairy products, oils, seafood, alcoholic drinks and soft drinks do not contain cellulose; The cellulose content of various infant foods is extremely low. Edible purpose of medicinal natural dietary fiber tablets: to moisten the intestines and relax the bowels, to get satiety and to decompose fat. Product features: scientific formula from natural ingredients is helpful for normal physiological activities; Get a sense of fullness. Cellulose can excrete toxins that cause diseases through the digestive system. Shorten the residence time of food in the intestine and make the stool unobstructed. It is composed of a variety of unique cellulose, which can decompose the ingested fat. Main ingredients: calcium hydrogen phosphate, cellulose, apple fiber, acacia flower, lecithin, calcium carbonate, citrus fiber, silicon dioxide, oat fiber, magnesium stearate, dextrin, maltodextrin, sodium carboxymethyl cellulose and sodium citrate. Suggested usage: Take one or two tablets each time, three times a day, with boiled water 20 minutes before or after meals. Related Content Cellulose and Health Not all carbohydrates can be digested and converted into glucose. Difficult-to-digest carbohydrates are called fibers. It is an indispensable part of a healthy diet, and it is high in fruits, vegetables, lentils, broad beans and coarse grains. Eating high-fiber food can reduce the possibility of intestinal cancer, diabetes and diverticulosis. And constipation is not easy to occur. Cellulose People usually think that fiber is "roughage", but this is not the case. Fiber can absorb water. Therefore, food residues can be expanded and loosened, and it is easier to pass through the digestive tract. Because the time of food residue staying in the body is shortened, the risk of infection is reduced; Moreover, some foods, especially meat, will produce carcinogens after deterioration, causing cell variation. Shortening the residence time of food residues in the body can also reduce the possibility of this happening. The fiber content in the diet of regular meat eaters is very low, which will increase the time of food staying in the intestine to 24-72 hours. In the meantime, some foods may go bad. So if you like meat, you must make sure that your diet contains a lot of fiber. There are many kinds of fibers, some of which are protein instead of carbohydrates. Some kinds of fibers, such as those contained in oats, are called "soluble fibers", which can slow down the absorption of carbohydrates by combining with sugar molecules. In this way, they can help keep the blood sugar concentration stable. Some fibers are much more absorbent than others. Wheat fiber can expand to 10 times its original volume in water, while glucomannan fiber in Japanese konjac can expand to 100 times its original volume in water. Because fiber can make food swell and slow down the release rate of energy in sugar, super absorbent fiber helps to control appetite and maintain proper weight. The ideal fiber intake is not less than 35 grams per day. If you choose the right food, you can easily reach this standard without additional supplements. JOhn Dickerson, a nutritionist at the University of Surrey, once stressed that adding Metz to a nutritionally deficient diet would do harm to health. The reason is that wheat drum contains a lot of phytate, which is an anti-nutritional substance and will reduce the absorption of many minerals including zinc. In short, it is best to obtain fiber from a large number of different food sources, including oats, lentils, broad beans, plant seeds, fruits and raw or slightly cooked vegetables. Most of the fiber in vegetables is destroyed during cooking, so vegetables are best eaten raw. Industrial application is suitable for dry mortar building materials, water-resistant putty powder (paste) for internal and external walls, adhesives, caulking agents, interface agents, water-based coatings, leveling agent and other new building materials. Worldwide, 8 million tons of cellulose is used for textile and paper making every year. In addition, rayon, cellophane and ester derivatives such as nitrate and acetate can be made of separated and purified cellulose. It can also be made into ether derivatives such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose and polyanionic cellulose, which are used in oil drilling, food, ceramic glaze, daily chemicals, synthetic washing, graphite products, pencil manufacturing, electronics, coatings, building materials, decoration, mosquito-repellent incense, tobacco, papermaking, rubber, agriculture, adhesives, plastics, explosives, electricians and scientific research equipment. Sodium carboxymethyl cellulose, commonly known as cellulose, carboxymethyl cellulose, cmc and other names, is a renewable and inexhaustible chemical raw material, which is widely used in textile, printing and dyeing, oil drilling, papermaking, ceramics, synthetic washing, daily chemicals, graphite products, pencil manufacturing, cigarette paper, coatings, building adhesives and other industries, especially in the oil drilling industry in recent years. This is inseparable from the vigorous development and scientific research of raw material manufacturers and machinery manufacturers related to cellulose. Compared with more than ten years ago, cellulose PAC for oil drilling has also occupied a place in the international market. Other industries, such as dry mortar building materials, waterproof putty powder (paste) for internal and external walls, adhesives, caulking agents, interface agents, waterborne coatings, leveling agent and other new building materials industries have made great progress, and the quantity and quality have been greatly improved. There are two main uses in paper industry: adding pulp and surface sizing. The addition amount of paper pulp is 3-5%, and a small amount can improve the longitudinal and transverse tension of paper by 30-50%, which plays a very good role in the use and writing of paper. Surface sizing, especially the water-retaining agent on coated paper, is an irreplaceable product of other adhesives and plays a very good role in the smoothness and smoothness of paper. The First Clinical College of Dalian Medical University and Dalian Institute of Chemical Physics of Chinese Academy of Sciences are introduced in detail. After years of cooperation, we have completed the "Basic and Clinical Application Research on the Prevention of Tissue Adhesion with Polypropylene Cellulose", and successfully developed a new high-tech material-Polypropylene Cellulose, which can be used to prevent tissue adhesion after creation and operation, and it has been proved to have good adhesion effect in basic experiments and clinical application research. How to make surgery not only cure diseases but also cause serious adhesion complications is an urgent problem to be solved in surgery today. 1993- 1999 The research group chaired by Professor Jiang Changming of Orthopedics has developed a new absorbable anti-adhesion material-carboxymethyl cellulose, which has carried out extensive basic and clinical prospective research in orthopedics, general surgery, neurosurgery and other disciplines. In the basic research, they cooperated with Dalian Institute of Chemical Technology, and successfully completed the synthesis and drug screening of polycellulose with polycellulose as raw material and polyglucose as crosslinking agent. The anti-adhesion effect of polymer fiber on tendon, nerve, dura mater, joint and abdominal cavity after operation was studied through animal experiments, which proved that the anti-adhesion effect was obvious. The clinical application study observed the effect of preventing muscle adhesion with multi-polymer fiber. Polypropylene cellulose has good biocompatibility and is an ideal anti-adhesion material. It can eliminate or reduce postoperative complications caused by adhesion, and reduce operative mortality and disability rate. Lignin fiber Lignin fiber is an organic fiber obtained by chemical treatment of natural wood, and its appearance is cotton wool-like, white or grayish white. Through screening, splitting, high temperature treatment, bleaching, chemical treatment, neutralization and screening, fibers with different lengths and thicknesses can meet the needs of different application materials. Because the treatment temperature is above 250℃, it is a substance with very stable chemical properties under normal circumstances and is not corroded by ordinary solvents, acids and alkalis. It is non-toxic, tasteless, pollution-free and non-radioactive, which does not affect the environment and is harmless to human body and belongs to green. The fiber microstructure is banded, uneven, porous and flat at the intersection, which has good toughness, dispersibility and chemical stability, strong water absorption, excellent thickening and crack resistance. Lignin fiber performance parameter length: all