The Effect Of Extracting Leaf Protein Concentrate From The Different Alfalfa At The Different Growth Stages

In this study,the seasonal plant height and nutrients of alfalfa were analyzed.The results showed that the height was decreasing with the increasing number of cutting times;as the plant approached maturity,the DM yield and the crude fiber(CF)content in DM increased,but the crude protein(CP)content in DM decreased. At the beginning of flowering season the CP and the CF achieves the optimal coupling exactly.The CP yield in paper unit area at the first cut was highest when the materials were harvested at the initial blooming stage.And then leaf protein concentrate is extracted from alfalfa by heating method.The purpose was to find the best processing parameter of extracting leaf protein.The optimum conditions of extraction for LPC were material with water was 1:3,NaCl concentration was 0.2%,temperature was 85℃,heating time was 7 min.At last,the effect of extracting leaf protein concentrate from the different alfalfa(Medicago.sativa)at the different growth stages was discussed.For example Medicago stiva L Gongnong No.1,Aohan,MagnumV, the paper studied extracting leaf proteins from alfalfa at the different of period and frequent cutting.The results showed that the best harvest time was at the beginning of florescence,and the leaf proteins obtaining of Gongnong No.1 was 3.42%,Aohan was 3.14%,MagnumV was 3.65%which crude proteins was more than 60%.At the first cutting,the yield ratio of leaf protein and crude protein from three different alfalfa, Gongnong No.1 was better than MagnumV,but MagnumV was better than Aohan.Because of the characteristics of MagnumV,it was better than Gongnong No.1 and Aohan alfalfa at the second and at the third harvest.With the cutting frequency increasing,the yield ratio and crude protein from the different alfalfa were steadily decreased.