Lettuce is low in carbohydrate and rich in inorganic salts and vitamins, especially nicotinic acid. Nicotinic acid is an activator of insulin, and diabetics often eat lettuce, which can improve the metabolic function of sugar. Lettuce also contains a certain amount of trace elements zinc and iron, especially the iron in lettuce is easily absorbed by the human body. Eating fresh lettuce often can prevent iron deficiency anemia. Lettuce is rich in potassium ion, which is 27 times that of sodium salt, which is beneficial to regulate the balance of salt in the body. For patients with hypertension and heart disease, it has the functions of diuresis, lowering blood pressure and preventing arrhythmia. Lettuce also stimulates appetite, stimulates the secretion of digestive juice and promotes gastrointestinal peristalsis. The method of cleaning pesticide residues Lettuce is difficult to clean, mainly because of its rough appearance and thin skin. So many people simply use water to eat in order to save trouble. In fact, Chinese flowering cabbage belongs to plants, with relatively low plants and fresh and juicy fruits, which are vulnerable to diseases, insect pests and microorganisms. Therefore, in the process of Chinese flowering cabbage planting, pesticides should be used frequently. These pesticides, fertilizers and germs easily attach to the rough surface of Chinese cabbage. If it is not cleaned, it is likely to cause diarrhea and even pesticide poisoning. To wash cabbage, it is best to wash it continuously with tap water. Flowing water can prevent pesticides from infiltrating into fruits. When washing lettuce, be careful not to take off the pedicle. If the pedicled lettuce is soaked in water, the residual pesticides will enter the fruit with the water, causing more serious pollution. In addition, don't soak lettuce with detergent such as detergent. These substances are difficult to clean and easy to remain in fruits, causing secondary pollution. However, if you eat lettuce too much or often, because the biochemical substances in lettuce can stimulate the optic nerve, it will cause dizziness and drowsiness, leading to night blindness or other eye diseases, so it is not appropriate to eat more. Night blindness and eye diseases caused by eating more lettuce will improve in a few days if you don't eat lettuce. Lettuce contains a variety of nutrients, including protein, fat, sugar, ash, provitamin A, vitamin B 1, vitamin B2, vitamin C, calcium, phosphorus, iron, potassium, magnesium, silicon and other trace elements and dietary fiber, so it can promote the development of bones, hair and skin and contribute to human growth. It is found that lettuce contains an aromatic hydrocarbon hydroxylated fat, which can decompose nitrosamines, a carcinogen in food, and prevent the formation of cancer cells. It has a certain preventive effect on liver cancer and gastric cancer of digestive system, and can also alleviate the reaction of cancer patients to radiotherapy or chemotherapy. ? Every 100g nutrient contains water 96.4g, protein 0.6g, fat 0. 1g, carbohydrate 0. 9g, crude fiber 0.4g, calcium 7mg, phosphorus 3 1mg, iron 2mg, carotene 0.03mg and thiamine 0. Lettuce can be eaten raw or cooked. There are many cooking methods. Lettuce is usually made into salad or sandwich with mayonnaise or seasoning. Lettuce salad is a Cantonese dish, which is simple to make and tastes good. 4. Add a few slices of lettuce to the end of cooking, which is delicious and nutritious. ? Taboo 1. Do not eat too much. Eating too much makes your eyes burn. Li Shizhen quoted Peng Chengyu as saying: Lettuce is poisonous, and all insects dare not go near it. When a snake bites, it can't see, and the poison on people is solved with ginger juice. 2. Not suitable for eating with cheese and honey. 3. People with cold constitution should not eat. 4. Patients with gout, urinary calculi and eye diseases should not eat five internal organs, dredge meridians and open the chest and diaphragm. Plant qi, strengthen bones and muscles, remove bad breath, whiten teeth and brighten eyes. And lactagogue's role. Diuretic excretion, relieving insect poison and snake bite poison. However, regular consumption can make people's eyes blurred. People who have a cold should not eat it. Lettuce is poisonous and harmful to people, and all kinds of bugs dare not go in. A child with abdominal pain has a cold in his abdomen, or an adult has a dull pain in his abdomen. If you don't like taking medicine, you can mash the stems and leaves of lettuce and cook them on the boiler as a drink to stop abdominal pain. Because there is a white emulsion in the stems and leaves of lettuce, it is called lettuce slice, and the English name is LACTUCAIUM. According to the pharmacist's research, it is said that this fruit juice has analgesic and anesthetic effects, and there is a new drug with emulsion components. Stopping tooth bleeding is usually due to weakness, yin deficiency, frequent bleeding between teeth, or dry nose, which is prone to nosebleeds. Lettuce stem slices can be cooked and mixed with soy sauce or salt to treat and reduce bleeding. When it is inconvenient for children to urinate, the lettuce stems and leaves can be mashed into mud and coated on the navel to make the urine gradually smooth. This method is included in a simple health prescription. Another method is to mash dozens of onions with ten lettuce stems, add honey or glycerin to make mud cakes, and apply them to the abdomen above the navel, which can also make the urine unobstructed. It is very important to warm the mud cake of lettuce with hot water before coating it to avoid catching cold. The position of the compress should leave the navel and be applied to the abdomen. Or fill the umbilical eye with cotton or gauze in advance to avoid liquid immersion, which is more appropriate. ("Sea") Prolactin can also induce diuresis and treat breast swelling, hemorrhoids, bleeding and sprain. Lettuce contains a lot of plant cellulose, which can promote intestinal peristalsis, dredge digestive tract and treat constipation. It is the best food for anemia patients. Other lettuce dishes for the treatment of postpartum lactation are decocted with wine. Another recipe: Lettuce seeds are mixed together, raw licorice is San Qian, glutinous rice and japonica rice are mixed in half, and porridge is often cooked. (Sea) Treat lettuce with urine and blood and apply it to the navel. (Summary) Lettuce with lettuce and lettuce juice. ("After Elbow") When a hundred bugs are in your ears, pound the juice with lettuce and drop it, and the bugs will come out. (Records of Shengji Zonglu) One point for raw vegetable leaves (dry) and one point for realgar. Mash the pineapple into powder, and use batter and pills as big as Gleditsia sinensis seeds. (Sheng Huifang) For waist flash injury, three ounces of white lettuce seeds (stir-fried), a pinch of white millet (stir-fried), half of frankincense, half of myrrh and half of ebony meat are ground into powder, and honey is added to make marbles. Every time you chew a pill, hot wine is served. Vaginal cyst is mixed with lettuce seeds, mashed into powder and boiled in a bowl of water for five times. Beverage processing 1. Material selection: choose fresh lettuce with big and thick leaves, and remove yellow leaves, dead leaves, insect leaves and old roots. 2. Pretreatment: the lettuce stems and leaves are separated, cleaned and disinfected, and the stems are peeled off. Cut the stem into discs with a thickness of 1 ~ 2 cm, and blanch in boiling water for 60 seconds; Cut the leaves into 2 cm long strips and blanch them in boiling water for 40 seconds to inactivate the enzyme, remove some bitterness and fix the color. To enhance the effect, 1% ~ 2% sodium chloride solution can be added to boiling water. 3. Color-protecting extraction: blanched lettuce slices and leaves are put in a mixed solution of 40PPM sodium sulfite and 200PPM magnesium acetate for 50 minutes. 4. mincing and filtering: putting lettuce slices and leaves together with the extract into a food processor for pulping, filtering, removing residues and leaving juice. 5. Mixed sterilization: 6% sucrose, 0. 1% malic acid, 0.4% propylene glycol alginate and 2% lettuce extract are mixed, mineral water is added to 100, and sterilization is carried out at 1 15℃ for 3 seconds. 6. Filling and sealing: aseptically filling and sealing the sterilized beverage, and cooling to room temperature to obtain the finished product. ? Processing of preserved lettuce. Selection of raw materials: select well-developed and large lettuce, wash it thoroughly, peel off the stem, cut off the old part of the root and the tender part of the upper part, and cut it into strips with a length of 4 cm, a width of 2 cm and a thickness of 1 cm. 2. Hardening treatment: generally soaked in lime water. Add 3kg of lime into every 100kg of clean water, stir evenly, take its supernatant, soak the lettuce strips in it, take them out after 12h, put them into clean water, rinse them thoroughly10 ~/2h, and change the water for 2 ~ 3 times. Finally, take it out and drain it for later use. 3. Pre-cooking: pour the lettuce strips into boiling water, heat and boil for 5-8 minutes, then take them out and cool them in cold water. Cooling, taking out, and soaking in a color protection solution containing 0.2% sodium sulfite for color protection. 4. Sugar making: it is completed in two steps: sugar pickling and boiling. Sugar stains: prepare 50% sugar solution to boil, add appropriate amount of citric acid, and then pour it into the soaking tank with lettuce strips for 2 days. Sugar boiling: take out the lettuce strips, adjust the concentration of the soaking solution to 50%, add the soaked lettuce strips after boiling, add a proper amount of sugar after boiling for 3-5 minutes to make the concentration of the sugar solution reach more than 60%, and heat and cook again for 15-25 minutes until the lettuce strips are transparent, and then take out the pot. Soak the sugar solution and lettuce strips in a jar for 24 hours. 5. Baking: Take out the lettuce strips made of sugar, drain the sugar solution, evenly put them on the baking tray, and send them to the baking room for baking. Bake at 65℃ ~ 70℃ for about 12 ~ 16 hours, and leave the room when the moisture content is 16% ~ 18%. When baking, pay attention to regular ventilation and dehumidification to facilitate drying, and do 1 ~ 2 times to make drying uniform. 6. Packaging: put the baked products in the room at about 25℃, regain moisture for 24 hours, check and trim, put them into food bags according to certain specifications and store them in a cool and dry place.

Lettuce (scientific name: lettuce? Lynn. ) is an annual or biennial herb in Compositae. It is 25- 100 cm high, the stem is upright and solitary, the basal leaves and the lower stems and leaves are large and undivided, oblanceolate, oval or elliptical, with a sharp tip, a short cone or a circle, and no stalk. The leaves on the lower part of the spike and the upper part of the spike are extremely small, egg-shaped and heart-shaped, and sessile. The heads are numerous or extremely numerous, arranged in panicles at the top of stems and branches. Achenes are oblanceolate, compressed, light brown, sharp-pointed, with a slender beak, almost as long as achenes. The flowering and fruiting period is from February to September.

This species is cultivated in the coastal areas of China and throughout China. It is a cold-resistant vegetable, which likes cold climate and is not resistant to high temperature. Like humidity. And is suitable for growing in clay loam or loam with rich organic matter and water and fertilizer conservation, and the propagation mode is sowing. Cultivated varieties include lettuce, lettuce and iceberg lettuce.

Edible, delicious and crisp, it is a popular vegetable. It can stimulate the secretion of digestive enzymes, stimulate appetite, promote the peristalsis of human intestinal wall and prevent constipation.