Studies On Chemical Extraction Mothod Of Dietary Fiber From Alfalfa

The study chose Alfalfa which was in nutrient period and fruited period as the research material and mainly concerned about the optimal extracting conditions of soluble dietary fiber and insoluble dietary fiber. Furthermore, the elementary research of physical and chemical characteristic of insoluble dietary fiber of Alfalfa was also made. The optimal conditions of soluble dietary fiber and insoluble dietary fiber which were extracted by chemical methods was determined by single factor experiment, orthogonal design experiment and variance analysis. The order of the influences of different factors was also researched. The result showed that:The optimal conditions of extracting soluble dietary fiber of Alfalfa which was in nutrient period and fruited period are the same. They were 80℃water temperature,3% acid solution concentration,50ml extracting solution, 120 min extracting time; But the influence of each factor to the extracting yield of soluble dietary fiber of Alfalfa which was in nutrient period and fruited period are different. The order of factors which affect soluble dietary fiber of Alfalfa which was in nutrient period was water temperature > acid concentration > he quantity of extracting solution > extracting time; the order of influence of Alfalfa which was in fruited period was water > the quantity of extracting solution> acid concentration> extracting time.The optimal conditions of extracting insoluble dietary fiber of Alfalfa which was in nutrient period was 8% alkaloid concentration, 80℃alkaloid soaking temperature, 60min alkaloid soaking time, 60℃acid soaking temperature; The water holding capacity of the material was 594%, swelling capacity was 4.53ml/g under this condition; the order of influent factor was alkaloid soaking temperature> alkaloid concentration> alkaloid soaking time> acid soaking temperature. The optimal insoluble dietary fiber extracting condition of Alfalfa which was in fruited period was: 8% alkaloid concentration, 80℃alkaloid soaking temperature, 90min alkaloid soaking time, 80℃acid soaking temperature; water holding capacity of the material was 637%, swelling capacity was 4.86ml/g under this condition; the order of influent factor was alkaloid concentration> alkaloid soaking temperature> acid soaking temperature> alkaloid soaking time.