Production Of Insulin-like Growth Factor-? From 10 L Bovine Colostrums And Repair Effect Of IGF-? On Rat Intestinal Mucosal Injury

Bovine colostrums are the milk that the cows secreted after delivery within 2~3 days.It is not only rich in nutrients,but also contains a large number of bioactive substances.Research showed that IGF-? widely exists in the bovine colostrums;it is the most important bovine colostrums growth factor.In this study,IGF-? was separated from bovine colostrums.The technological conditions was studied,which include degreasing by centrifugation,rennet curdling,using acid-alcohol to remove IGFBP and removing impurities protein through ultrafiltration.The results showed that the optimum degreasing conditions of centrifugal temperature was 36 ?,centrifugal speed was 4000r/min and centrifugal time was 15 min.The optimum preparing whey of skim milk temperature was 36 ?,p H value was 6.5,volume ratio of papaya enzyme to skimmed milk was1:50.coagulation time was 40 min.Under low temperature,the volume ratio was 1?4 that the optimum removing IGFBP with acid and alcohol solution from whey at 4 ?.Most impurities protein can be removed through ultra-filtration with molecular weight cut-off 60 KD~80 KD membrane.Micromolecular impurities protein and lactose could be removed with molecular weight cut-off 10 KD~20 KD and 6 KD membrane,respectively.The optimum ultra-filtration of temperature was 36 ?,pH value was 5.5,operational pressure was 0.06 MP and temperature was36 ?,pH value was 8.0,operational pressure was 0.06 MP.Above technology route was applied in a large scale(10 L bovine colostrum)to produce IGF-?.63.02 g powder was obtained,the IGF-? relative concentration was2106.63 ?g/g,and IGF-? recovery rate was 48.79%.Sodium hydroxide solution was used to cleaning membrane,and researched the effects of different temperature,rate of flow,time on the purge of 60 KD~80 KD membrane.The optimum cleaning conditions of temperature was 35 ?,rate of flow was 40 L/h and time was 25 min.Inflammatory bowel disease(IBD)rat model was established.Interventionexperiment on rat was carried out.Through determining MPO activity,SOD activity and colonic morphologic observation,it is suggested that exogenous IGF-? from bovine colostrum had certain repairing effect on intestinal mucosa injury.