VB 1 (thiamine) is very easy to be destroyed at high temperature, especially in high-temperature alkaline solution, which is easy to be destroyed by ultraviolet rays. In acidic solution, it is stable even when heated.
(1) physiological function
VB 1 is the main component of decarboxylation coenzyme, which participates in the oxidative decarboxylation of pyruvate and α -ketoglutarate in carbohydrate metabolism. It can inhibit the activity of cholinesterase and maintain the normal peristalsis of gastrointestinal tract and the secretion of digestive glands.
(B) VB 1 defect
When VB 1 is deficient, carbohydrate metabolism in nerve tissue is blocked first, which leads to pyruvate accumulation in nerve tissue, causing polyneuritis and beriberi, also known as beriberi, which is more common in areas where rice is the staple food. It is especially common in Southeast Asia, especially in the Philippines, Vietnam, Thailand, Myanmar and other countries. It is rare in China since the founding of the People's Republic of China, but in recent years, due to the improvement of living standards and the increase in the consumption of polished rice, the prevalence rate in some areas has rebounded. It can also be caused by alcoholism, various gastrointestinal diseases, tuberculosis, hyperthyroidism and other diseases with relatively insufficient consumption.
Due to insufficient diet, symptoms usually appear after taking a diet with low VB 1 for 3 months. Early manifestations are fatigue, muscle pain, loss of appetite and weight loss. Then there are typical symptoms: ascending symmetrical peripheral neuritis, which first occurs in the lower limbs and is distributed like socks; Paresthesia, myasthenia, tachycardia, precordial pain; Severe cases show heart failure and edema. Clinically, it can be divided into four types: ① dry type, with peripheral neuritis as the main manifestation; ② Wet type, mainly edema and serous exudation; (3) fulminant type, characterized by acute cardiovascular system, accompanied by phrenic nerve and recurrent laryngeal nerve paralysis; (4) Mixed type, with the above two or more performances.
(3) Food sources
Foods rich in VB 1 include cereals, beans, dried fruits, yeast, hard-shelled fruits, etc., especially in the epidermis of cereals, so the grinding accuracy should not be excessive. The contents of animal viscera, eggs and green leafy vegetables are also very high, and the contents of celery leaves and lettuce leaves are also very rich, so we should make full use of them. Although the potato content is not high, the area where potatoes are the staple food is also the main source of VB 1. Thiaminase is found in some fish and mollusks. Eating raw will cause the loss of VB 1 in other foods. Therefore, it is neither hygienic nor scientific to eat fish raw but shrimp alive.
(4) supply
The demand of VB 1 is directly proportional to the total calorie intake of the body, so the supply of VB 1 is expressed by the heat supply per 4.2MJ( 1000kcal). Accordingly, the recommended supply of VB 1 in China is 0.5 mg/4.2 MJ ..
(5) Evaluation of nutritional level
1. In the load test, the subjects took VB 15mg orally in the morning, and then collected urine within 4 hours. The content of VB 1 was determined: < 100μ g was nutritional deficiency, 100 ~ 200μ g was insufficient, and > 200μ g.
2. The ratio of VB1to fasting urine creatinine content < 27 is insufficient, 27 ~ 65 is low, 66 ~ 129 is appropriate, and ≥ 130 is high.
3. Determination of glycolaldehyde activity in red blood cells This is a specific index used to determine the nutritional status of VB 1. If TPP (thiamine pyrophosphate) effect is greater than 16%, it means that VB 1 is deficient.
Lutein is a new star in the field of plant matter, and it is now favored by people. Lutein is not only an antioxidant that inhibits the risk of cancer and heart disease, but also plays an important role in protecting eyes. Lutein is an important carotenoid in the eyes. According to a recent report in the journal Ophthalmology, foods containing lutein can prevent and treat cataracts and protect eyes with age-related macular degeneration.
Age-related macular degeneration (ARMD) is the leading cause of permanent blindness in people over 65 years old. 130,000 people in the United States suffer from ARMD symptoms, and it is estimated that120,000 people suffer from visual impairment due to this disease. With the increase of the population over 65, it is estimated that this number will double by 2050. From the perspective of national health, this issue is very important in the coming year. At present, there is no effective means to prevent ARMD. However, by increasing the intake of foods with high lutein content, it is possible to reduce the possibility of ARMD.
Lutein not only has the function of preventing ARMD, but also is considered to have a therapeutic effect on this eye disease. Dr Stuart Richards, the head of the vision examination department of CVA treatment center in the United States, conducted a study to study the effect of lutein-rich food on restoring eye diseases caused by ARMD. Richard's discovery was presented at the annual meeting of the Southern Committee of American Visual Examiners held in February, 1999. It mentioned: "As long as the photographic intake of food rich in lutein is increased, the visual function of patients will have a good effect."
Richard ingested 5 ounces (about140g) of spinach from the subjects four to seven times a week, and observed it for three months, and found that his visual function recovered.
According to the national health interview survey, between 1.987 and 1.992, lutein intake was supported by all the students surveyed, and the number of adults aged 40 to 69 decreased by 1.6%. It is generally believed that green vegetables or leaves are rich in lutein, indicating that it is not appropriate for them to consume crops containing lutein at this time. According to the research, kiwifruit is the most abundant food containing lutein, followed by yellow corn and egg yolk. Lutein cannot be synthesized in the body and must be taken from food.
Kiwifruit produced in California contains the most lutein. A member of the Kiwifruit Committee in California said: "Kiwifruit is rich in nutrition, which may be one of the most superior food raw materials from the perspective of effective health."
From June 10 to March of the following year, kiwifruit in California can be delivered to consumers as fresh fruit. According to Scott Horsfall, chairman of the Committee, "the demand for processed kiwifruit is increasing ... the demand for kiwifruit in the world and the United States is further increasing. The consumption of kiwifruit in 1999 is the highest consumption level in the United States since 1994. "
Keminghut Manufacturing Company (located in Des Moines, Iowa, USA), which produces lutein, has signed many contracts on lutein as fortified functional food. Chek Brass, Ming Kai's deputy manager in charge of sales and business development, said: "Several companies that may become the company's customers in the future are now conducting research on adding lutein to food or drinks. Some original beverage companies expect to use lutein called "flora" as a food additive from June to August now. " The company claims that its lutein products soluble in cold water are ideal for beverages.
Ming Kai's "Flora" lutein is the same as lutein in fruits and vegetables. It is said that in order to produce lutein with high concentration and purity, the company used a patented process. In fact, this product is exactly the same as lutein in vegetables such as spinach and cauliflower in chemistry.