Studies On Extraction And Application Of Alfalfa Leaf Protein

Alfalfa leaf protein has been known very well, because it has many Characteristics such as extensive source, abundant nutrition, excluding animality cholesterol, defending and curing the disease, defending decrepitude and oldness,and strengthening body. And alfalfa leaf protein contains abundant Mineral element, Vitamin and Natural pigment. Alfalfa leaf protein is considered as a new high exploiting value protein source by FAO (Food Agriculture Organization).Compacted alfalfa was used in this experiment as raw materials for extracting protein by different methods such as moisture addition, sock time, heating time and PH value to find the optimum technique and additions of extracting alfalfa leaf protein. At the same time, using enzyme (cellulose enzyme) destroyed cell wall, and made a preparatory study on extracting leaf protein by enzyme. The results showed that the decreasing order of the factors affecting the alfalfa protein yield and crude protein content was socking time>temperature>pH>adding water. The most optimum extracting conditions were 3 minutes for sock, the ratio 1:7 for compacted alfalfa to water, heating temperature at 80℃and the pH4.0. The protein extracted with the method of combining acid with centrifugation whose protein yield was 34.2% and crude protein dry content was 50.03%.The protein yield was higher than 17.75%～26.04% for machine destroying cell wall, and far higher 9.05%～12.02% than using enzyme (cellulose enzyme) destroying cell wall. And the method made crude protein dry content increase to 50.03%. On the other hand, the protein extracted with the method of combining acid with centrifugation whose content was 79.72% more than protein content 46%-70% reported from other literatures.Alfalfa leaf protein is dark green and grass flavor, which make it restrict applying in food industry. For shucking off green and grass flavor and extracting crude pigment, the experiment was done. Under the condition of using anhydrous ethanol as soaking extractant, the optimal operating conditions influenced the decolourization and fishy odor elimination of the leaf protein concentrates of alfalfa were determined by orthogonal design. The most optimal conditions were: liquid/solid of 1:17, and soaking at 60℃for 6h.Further studies were conducted to investigate the effects of factors including protein concentrations,temperature,pH levels,NaCl concentration on the functional properties of alfalfa protein, i.e. protein water absorption properties, solubility, emulsifying properties, and foaming properties. The results showed that alfalfa leaf protein do not have good solubility, but have good emulsifying properties and emulsifying stabilization properties, and foaming properties and foaming stabilization properties. If ameliorate its solubility by physical or chemic methods, which must increase application scope.In the end, the article analysised the effect of alfalfa protein on paste rheology properties and cookie baking properties to affording technics parameter and theory foundation for using in food industry, and studyed the degree of nutrition aggrandizement and its mechanism of effect. The results showed that alfalfa was a good crude nutrition aggrandizement and paste improver(weakening wheat gluten), alfalfa leaf protein incorporated into wheat flour can intercede effectively wet wheat gluten content, and increase wheat gluten strength,weaken wheat gluten,and made cookie crisp. The cookie added alfalfa leaf protein was very crisp. And the cookie had good colour luster and organization structure, and had lite and gratifying grass flavor. The proper level incorporated into wheat flour was 2%.