Sources of Dietary Fiber and Its Products
Dietary fiber resources are very rich, mostly in the seed coat and outer skin of plants, such as wheat bran, bean dregs, pomace, bagasse, buckwheat husk, etc.
1. There are two main aspects of dietary fiber products:
One is cereal products rich in dietary fiber (such as whole wheat bread)
The second kind of dietary fiber products is formula foods reinforced with dietary fiber.
2. Common types of dietary fiber are:
1. Rice bran The dietary fiber content of rice bran is 35-40%, which not only has good flavor, but also has good stability and is not easy to become rancid. In addition, it also contains certain vitamins and has certain nutritional value.
2. Bran powder contains as much as 70% of food fiber and contains almost no phytic acid. In addition, it contains more calcium, phosphorus, iron, copper, zinc, etc., which has certain nutritional value. Often used in bread and meat products.
3. Pea fiber is made from pea shells. The product contains a certain amount of pea germ. The food fiber content is 45%. The product is light green. When used in bread, it is "creamy white" and has a soft pea fragrance.
4. Water-soluble dietary fiber mainly includes gum arabic, guar gum and locust bean gum. Often used in soups and soft drinks.
5. The apple and pear dietary fiber contains about 70% of dietary fiber. Does not contain phytic acid.
6. Tomato powder is not only of good quality, but also contains protein, vitamins and minerals.
7. Other Peanut shell powder, dietary fiber content is 47%, also contains phosphorus, calcium, potassium, etc.
The similarities and differences of the nutritional components of soy milk and milk
Ⅰ. The nutritional content of milk
1. Protein: The protein in milk is mainly casein, albumin, globulin, milk protein, etc. Among the more than 20 amino acids it contains, there are 8 essential amino acids for the human body. Milk protein is a full-priced protein. The absorption utilization rate is as high as 98%.
2. Carbohydrates: mainly lactose
3. Fat: mainly saturated fat and cholesterol
4. Minerals: calcium, potassium, magnesium, etc. The calcium in milk is the closest to the human body and is the food with the highest calcium absorption rate.
5. Vitamins: mainly vitamin D and vitamin B12.
Ⅱ. the nutritional content of soy milk
1. Protein: The amino acids contained in soy protein are essential amino acids for the human body, belonging to high-quality protein, with a content of about 30%.
2. Carbohydrates: mainly starch, soybean oligosaccharides and cellulose. In addition to starch providing energy, soy oligosaccharides and cellulose contribute to intestinal health, and the content is 22-35%.
3. Fat: The content of lecithin is 18-22%, mainly unsaturated fatty acid (linoleic acid, linolenic acid), which has the function of brain strengthening, anti-aging, lowering blood fat, anti-fatty liver, preventing and treating Alzheimer's and Special effects such as memory loss.
4. Minerals: mainly iron (higher than milk), potassium, sodium, calcium (not high in milk), and magnesium, which are beneficial to promote the development of skeletal muscles.
5. Vitamins: mainly containing water-soluble vitamin carotene, vitamin B complex, vitamin C, and vitamin E. Among them, vitamin E has the effects of delaying aging and preventing cardiovascular diseases. (Va, vd, riboflavin are not as high as milk)
6. Soy isoflavones: It is a kind of phytoestrogens, which can improve menopausal disorders and osteoporosis. It also has the effect of reducing low-density protein and helps lower cholesterol.
7. Anti-nutritional factors: Trypsin inhibitors can hinder the absorption of human protein. Cooking soybeans for about 8 minutes can inactivate trypsin by 85%.
Diabetics' dietary combination and problems to be noted
1. Controlling total heat energy is the primary principle of diet therapy for diabetic patients. The calorie intake can maintain normal weight or slightly lower than ideal weight. Those who are obese must reduce their caloric intake, and those who are lean can increase calories appropriately to gain weight. 2. Supply sufficient dietary fiber. You should eat some vegetables, wheat bran, beans and whole grains in your diet.
3. Control fat intake.
4. Supply the right amount of carbohydrates. At present, it is recommended not to control carbohydrates too strictly. Sugars should account for about 60% of the total calories. The daily food intake can be 250 grams to 300 grams, and the fat should be 150 grams to 200 grams. Cereals are also the main source of heat energy in daily life. Each 50 grams of rice or white flour provides about 38 grams of carbohydrates.
5. Supply sufficient protein. When kidney function is normal, the dietary protein of diabetes should be similar to that of normal people. However, when combined with kidney disease, the protein quality of the daily diet should be reasonably arranged under the guidance of a nutritionist. Milk, eggs, lean meat, fish, shrimp, and soy products are rich in protein. Priority should be given to eating high-quality protein.
What problems should be paid attention to in the diet of diabetes? The treatment of diabetes must be based on diet control and exercise treatment. Diabetes patients should avoid sugar and sugary foods, reduce the intake of high-fat and high-cholesterol foods, eat moderate amounts of high-fiber and starchy foods, and eat smaller meals.
Why do people who faint due to hunger or weakness usually use glucose for energy instead of sucrose or fructose or starch?
Need to supplement glucose, supplement the body's heat energy, improve cell metabolism, and glucose can be directly absorbed without digestion, which can quickly supplement the body's heat energy.
Attention should be paid to problems in nutritional evaluation of food protein
(1) First determine the protein content and amino acid pattern, and calculate the amino acid score corrected for protein digestibility.
(2) Pay attention to the changes in protein during food processing. This is usually to determine the utilization of lysine and methionine, because they are most easily destroyed during food processing. This may also be the reason why biological evaluation is lower than chemical evaluation.
(3) It is best to carry out appropriate analysis tests on nitrogen, amino acids and various toxins including microbial toxins in the sample to remove the effects of non-protein substances.
(4) Finally, the test protein should be tested to meet the requirements of the human body. This work should be very prudent and careful.
In addition, the method of amino acid scoring is relatively simple, but does not consider the digestibility of food protein. In recent years, the US Food and Drug Administration (FDA) has proposed a new method, that is, the amino acid score with digestibility correction. The calculation formula is as follows
Digestibility corrected amino acid score (PCDAAS) = amino acid score × true digestibility
The essential amino acid composition pattern of the protein contained in food is different from that required by the human body, so it cannot be fully utilized by the body. The various amino acids contained in different food proteins have their own strengths and weaknesses; while eating at the same time, they can learn from each other's strengths and complement each other, so that the composition of the various amino acids that enter the human body is close to the body's need to synthesize its own protein. It is the complementary effect of food protein.
For example, the protein of cereals contains less lysine, but its methionine and cystine content is high; while soy protein is just the opposite, lysine content is high, but methionine and cystine content is low. Combining grains and soybeans can make up for the shortcomings of both. Wowotou made from cornmeal and soybean flour, laba porridge made from whole grains, and "milk substitute" made from rice flour with milk powder and egg yolk powder are all examples of using the principle of protein complementarity to improve the nutritional value of protein.
When using protein complementarity to improve protein nutrition, attention should be paid to: ①The more varieties of foods, the better, for example, meat and vegetables have a better effect. ② Various foods should be eaten at the same time, because all essential amino acids must be in place at the same time before they can be used to synthesize human protein.
Nitrogen balance is a way to reflect the protein metabolism in the body. It actually refers to the comparative relationship between protein intake and excretion.
As there are many difficulties in directly determining the protein consumed in food and in the body, the nitrogen content of various food proteins is quite close (about 16%), and most of the nitrogen-containing substances in general food are protein. Therefore, the method of determining nitrogen content is often used to indirectly understand the balance of protein.
When dietary protein is supplied properly, the intake and discharge of nitrogen are equal, which is called the total balance of nitrogen. Children are growing, and new tissues are growing in pregnant women and newly recovered patients. Part of the protein that it ingests becomes new tissue. At this time, the intake of nitrogen must be greater than the output, which is called the positive balance of nitrogen. As for the hungry, those who eat a protein-deficient diet, and the patients with wasting diseases, their daily intake of nitrogen is less than the discharge of nitrogen and they are becoming thinner. This situation is called the negative balance of nitrogen
Protein metabolism and nitrogen balance
The total metabolism of protein in the body can be expressed by nitrogen balance, that is, the difference between nitrogen intake and nitrogen excretion. The average nitrogen content of protein is 16%.
The nitrogen balance formula is as follows: B = I-(U + F + S)
B: nitrogen balance; I: intake of nitrogen; U: urine nitrogen; F: fecal nitrogen; S: skin loss of nitrogen.
If the difference is positive, it represents a positive nitrogen balance, indicating that nitrogen is retained in the body or used for protein growth; on the contrary, a negative nitrogen balance represents nitrogen loss; it can also be a zero nitrogen balance.
The effect of nitrogen balance on the body
In fact, N balance is not absolute.
In a day, N balance is positive when eating; N balance is negative when not eating at night; this fluctuation is relatively stable after 24 hours.
The body has a regulatory effect on N balance within a certain limit. When a healthy adult's daily intake of protein increases or decreases, the decomposition rate of protein in the body and the amount of nitrogen excreted with urine also increase or decrease. For example, the amount of nitrogen excreted in the urine increases when eating a high-protein diet, and vice versa. However, if you eat a low-protein diet for a long time, the protein in the body will still be decomposed, so a negative balance of nitrogen is likely to occur. If the amount of protein consumed is too large, not only the body cannot use it, but it even increases the burden on the digestive organs and kidneys. However, the amount of protein required is different from energy. There is a big difference between the amount of protein required and the amount of harmful effects caused by a large intake of protein.
Changes in protein and amino acids during food processing
Food processing is usually to kill microorganisms or inactivate enzymes to protect and preserve food, destroy certain nutritional inhibitors and toxic substances, improve digestibility and nutritional value, increase convenience, and maintain or improve sensory properties.
However, in the pursuit of these effects of food processing, it often brings some adverse effects of processing damage. Due to the important nutritional role of protein, especially essential amino acids, people pay great attention to the changes in food processing.
Beneficial effects: Sterilizes enzymes; improves protein digestibility; destroys certain taboo ingredients; improves the sensory properties of food
Adverse effects: Heating has certain damages to the nutritional value of protein and amino acids: amino acids are destroyed, oxidized, desulfurized, protein denatured, etc.
Protein deficiency occurs in both adults and children, and it is especially sensitive to children in the growth stage: it is the most harmful nutritional disease among the many malnutritions of the human body.
There are two types of protein-caloric malnutrition: One type of edema: Kwashiorker's disease (Gasica's disease), a nutritional disease of children in which the caloric intake is basically satisfied and the egg quality is severely insufficient, mainly manifested as abdominal and leg edema. Weakness, indifferent expression, slow growth, discoloration of hair, brittle and easy to fall off, susceptible to infection. The other is wasting type, which refers to children's nutritional diseases with severely insufficient egg quality and caloric energy intake. The children are wasting and weak, and die because they are susceptible to other diseases. Insufficient protein intake in adults can cause physical decline, edema, and weakened disease resistance. Some people think that these two kinds of malnutrition are two different stages of protein-heat energy malnutrition. For adults, insufficient intake of egg quality can also cause harmful effects such as decreased physical strength, edema, and weakened disease resistance.
Causes of protein deficiency:
Insufficient supply of protein and calories in the diet
Malabsorption, mainly intestinal diseases
Protein synthesis disorders, mainly caused by liver disease, hepatitis, cirrhosis, liver cancer, etc. Liver lesions will reduce the ability of the liver to synthesize protein, resulting in negative nitrogen balance and hypoproteinemia, which become one of the causes of ascites and edema.
Too much protein loss, too much decomposition. The main cause of protein loss is nephritis.
The principle of nutritional treatment of protein deficiency is to find out the cause, comprehensively strengthen nutrition, and improve the nutritional level of the patient as soon as possible; provide a low-fat diet with sufficient heat and high-quality protein, and supplement vitamins and minerals, and use liquid food for those with reduced digestive function , Eat small meals frequently to improve protein nutrition.
Excessive protein intake:
Eat more animal fat and cholesterol.
Increase the burden on the kidneys.
Excessive intake of sulfur-containing amino acids can accelerate the loss of calcium in the bones, and easily lead to osteoporosis.
Physiological functions of trace elements
Causes of mineral deficiency:
The distribution of various elements in the earth's environment is not balanced; natural mineral antagonists in food; mineral loss during food processing; insufficient intake or poor eating habits; special populations
The physiological functions of calcium
(1) Make bones and teeth
(2) Regulate ion transport across membranes, especially in the process of nerve signal transmission
(3) Participate in the process of muscle contraction and help maintain normal blood pressure
(4) Related to the secretion of hormones and digestive enzymes
(5) Participate in the coagulation process
A constant element necessary for the human body. The chlorine content of adults is 82-100 g, which is about 0.15% of body weight. Chlorine in the body is mainly combined with sodium and potassium.
1. Maintain the volume and osmotic pressure of extracellular fluid;
2. Maintain the acid-base balance of body fluids;
3. Participate in blood CO2 transportation;
4. Participate in the formation of stomach acid, promote the absorption of vitamin B12 and iron.
Food source: sodium chloride
Effects of iron deficiency:
(1) Anemia: manifested as fatigue, indifference, and decreased work ability. Children may be agitated, irritable, lack of concentration, and decreased academic performance
(2) Influencing behavior and intelligence, impairing children's cognitive ability
(3) Decreased resistance to infection and cold resistance
(4) Anemia in the first trimester is related to premature delivery, low birth weight and fetal death
(5) Pica (pica)
Iron excess and toxicity
(1) Acute iron poisoning: It often occurs after taking high-dose iron preparations, which manifests as hemorrhagic necrosis of the gastrointestinal tract.
(2) Chronic iron poisoning and iron overload: hemochromatosis occurs, manifested as organ fibrosis.
Physiological function: Partially replace the hydroxyl ions of hydroxyapatite in bones to form fluorapatite to maintain the structural stability of bones and teeth; fluorapatite can form a protective layer of fluorapatite crystals on the surface of teeth to resist acid corrosion . Fluoride can improve dental caries and reduce the prevalence of dental caries in children and adults.
Absorption and metabolism: About 75% to 90% of the fluorine in the diet is rapidly absorbed into the blood from the gastrointestinal tract and distributed throughout the body in the form of ions. The fluoride ions in most bone tissues rapidly exchange with the hydroxyl ions in hydroxyapatite to form fluorapatite.
About 50% to 80% of the fluorine intake is excreted in urine every day.
Deficiency and excess of fluoride
Fluoride deficiency can affect bone formation, cause tooth hypoplasia, or increase the incidence of dental caries.
Excessive fluoride can cause fluorosis, such as skeletal fluorosis and dental fluorosis.
Fluorine supply and food sources
The Chinese Nutrition Society recommends: AI for adult fluoride: 1.5mg/d; UL: 3.0mg/d
The fluorine content in general food is low. Drinking water is the main source of fluorine. The content of fluorine in drinking water depends on the level of fluorine in the soil.
Polyunsaturated fatty acids
Physiological significance: Polyunsaturated fatty acids with important physiological significance are n-3 and n-6 series, linoleic acid and linolenic acid are n-3 and n-6 respectively
- Fructo Oligosaccharide
- Malt Oligosaccharide