Alfalfa is an annual or perennial high-protein plant, originated in the Near and Middle East, is the world’s earliest domesticated, popularized the most important fodder crops, at home and abroad known as “the king of pasture” reputation, in China’s Shaanxi Province, Gansu Province, the Northeast and other places of extensive cultivation.

China’s alfalfa planting area ranks fifth in the world, with more than 960,000 hectares. At present, with the improvement of people’s living standards, a variety of refined food ingredients, often sugar, fat content is high, and including dietary fiber, including functional, health care components are insufficient, which leads to human obesity, rectal cancer, atherosclerosis and other diseases such as the incidence of increased.

Therefore, the study of scientific and reasonable dietary ratios, including the use of functional nutrients in natural plants, and the development of functional health foods will be an important area of food development in the 21st century. Since alfalfa phytochemicals contain special immune-active proteins, polysaccharides and a variety of minerals, dietary fibers and other special nutritional and functional components, it is a valuable food resource worth developing and utilizing.

Types of alfalfa and its main components

There are three species of alfalfa: alfalfa, yellow alfalfa and gelatinous alfalfa, which can be crossed successfully and have the same chromosome type regardless of diploid and tetraploid plants. After more than 2,000 years of cultivation and domestication, fifteen local varieties adapted to different climatic and soil conditions and seven artificially bred varieties have been formed. Together with one variety introduced from abroad, there are twenty-three alfalfa varieties that have been validated and registered in China.

Nutritional and functional components of alfalfa

1. Protein composition and characteristics of alfalfa
Alfalfa has high protein content and yield. One hectare of alfalfa stems and leaves can extract 2750-3805kg of protein, which is 1.8 times higher than that of soybeans, and the number of main amino acids contained in alfalfa is 67% more than that of soybeans.

In industrial extraction, the yield of alfalfa leaf protein far exceeds that of crop seed protein, and the amino acids of concentrated leaf protein are two times higher than those of lysine corn. Therefore it will be able to be used as a new resource of edible protein with high nutritional value.

Leaf protein has a complete range of amino acids and a balanced composition ratio (see Table 2), has aroused widespread interest in many countries. Although the research on leaf protein in China started late, it has developed rapidly, and it is mainly used in feed as a new protein resource instead of fishmeal, while there are few reports on its application in food.

The extraction of edible alfalfa leaf protein (EdibleAlfalfaLeafProtein, EALP) is mainly from the fresh green leaves, which is made by coarse crushing, filtration, heating, protein coagulation, centrifugation, rinsing, centrifugation and sieving.

In edible alfalfa leaf protein, the protein content is as high as 57.9% (62.9% dry basis), the dietary fiber content is as high as 12.7% (13.8% dry basis); moisture, fat, ash and available carbohydrates are 7.9%, 6.8%, 5.4% and 9.6%, respectively. Therefore, EALP is a good high-protein additives, added to the food can simultaneously increase the protein and dietary fiber content of food.

2. Immunoactive polysaccharides
So far, there are many polysaccharides with immune activity, but only a few polysaccharides extracted from shiitake mushrooms and cloud mushrooms have been used in clinics, and the reasons for the lack of application are not only poor clinical effects and toxicity.

However, most of the plant polysaccharides are non-toxic, so they have been emphasized. Alfalfa polysaccharides are plant polysaccharides extracted from alfalfa, and the number of research reports in this area is relatively small.

According to relevant experimental reports, MSP does not contain protein, tannin and starch, and is an acidic polysaccharide. It contains glucose, mannose, rhamnose, galacturonic acid and another unknown monosaccharide, and the ratio of the contents was not measured. The molecular weight of MSP examined by ultrafiltration was in the range of 20-60 thousand. The immunopotentiating effect of alfalfa polysaccharides is reflected in:
(1) promotion of exogenous lectin response. In vitro, MSP could stimulate PHA, CONA, LPS, and PWM-induced mitogenic responses quite significantly, with statistical significance at polysaccharide concentrations of 31-62 mg-mL-1.

(2) MSP has an effect on the organism’s ability to produce antibodies. It can increase the ability of the body’s lymphocytes to produce antibodies.

3. Dietary fiber in alfalfa
Although dietary fiber is a non-nutritive component, it can reduce blood lipids, plasma cholesterol, especially LDL cholesterol, and raise HDL appropriately. it can also reduce bile acids and decrease the reabsorption of bile acids in the small intestine. In addition, dietary fiber can bind carcinogenic substances in the intestinal lumen, reduce fecal residence time, and thus reduce the contact between the mucosa of the large intestine and carcinogenic substances.

4.Other nutritional and health care values of alfalfa
With increasing industrialization, environmental pollution has intensified, causing urban fatigue, leading to nutrient imbalance and mineral deficiency in the human body. Calcium deficiency is a particularly prominent problem, so calcium supplementation is imperative.

Alfalfa is rich in vitamins and minerals, especially calcium content in 1.13% to 1.7% (dry matter percentage), phosphorus content is more than 0.2% to 0.3%, so as long as a small amount of food added to the human body these nutrients can be supplemented to meet the needs of the human body.

In addition, in recent years found that alfalfa saponins for the treatment of high cholesterol effective. Because of the saponin components can make the cholesterol content reduce, thus indirectly play a role in protecting the heart function.

Comprehensive development and utilization of alfalfa food

At present, the development and utilization of alfalfa for human food is rarely reported, and in the future, in this field, in-depth research and development can be carried out in the following aspects.

1. Utilization of alfalfa whole powder
The production of alfalfa flower and leaf nutritional powder has been applied. This kind of nutritional added powder is mainly used to mix with wheat flour, while making a kind of mixed nutritional flour. If the addition ratio is 3, the protein content of each hundred flour can be increased by 1g, and the calcium content can be increased by 30~50mg.

If you add 0.5 iodized salt in the mixture, the iodine content per hundred grams of flour can be increased by about 25 μg. The use of this mixture of rice flour can be produced a variety of new nutritious food. Such as rolls, steamed buns, cookies, instant noodles and so on.

But the current application of alfalfa in food is limited to pasta products. It has not yet formed a unique type of functional health food. According to the characteristics of functional components of alfalfa, we can develop health food, such as functional powder.

2. Utilization of alfalfa protein
Alfalfa is rich in high quality protein. The high-quality protein, dietary fiber and edible polysaccharide in alfalfa can be separated and purified to produce high-protein food, such as high-protein noodle products, dairy products, meat products, beverages, children’s food, food for the middle-aged and the elderly, and so on.

3.The utilization of alfalfa immunopolysaccharide
Alfalfa contains about 1% of high quality plant polysaccharides. Alfalfa polysaccharide itself, especially after isomerization or modification, has good anti-tumor effects, immune-enhancing effects on T-cells and B-cells activation, blood lipid-lowering, blood sugar-lowering effects, detoxification, antibacterial, anti-radiation and other effects. The above functions can be utilized to develop special medicines and health food.

4. Utilization of alfalfa dietary fiber
Alfalfa can be used as the source of dietary fiber extraction. It can be used to develop health food with dietary fiber effect.