The New Technology Of Aqueous Enzymatic Extraction Of Feeding Rapeseed Protein

The key problem in stockbreeding of our country is short of protein resource. In order to fully explore the rapeseed protein resource, we carried out aqueous enzymatic extraction which included the study on selecting enzyme and its treatment parameter, aqueous extraction technology after zymohydrolysis, the research on aqueous enzymic hydrolysis for rapeseed protein after ultrafiltration..During the study on the selection of enzyme and treatment parameter, we selected cellulose, hemicellulose, pectinase, protease, complex-enzyme I (protease, cellulose, pectinase were mixed in line with their activity ratio of 5:3:2), and complex-enzyme II (cellulose, pectinase in line with their activity ratio of 3:1). we calculated the output rate of rapeseed oil and rapeseed protein and made a contrast between this method and the traditional aqueous extraction without enzyme. It proved that the function of complex-enzyme was obvious, single cellulose, hemicellulose and pectinase were not so effective. To treat the rapeseed with complex-enzyme II, RSA was adopted to study the effect of the enzyme reaction parameter to the output rate of rapeseed oil and rapeseed protein, the results showed that the proper technology parameter were supposed to be as follows: the ratio of solid and liquid was 1:5, the enzyme quantity was 30u/g, and the enzyme treating time was 100 min.During the studying on water-extraction technology after enzymatic extraction we studied the effect of water-extraction condition after enzymatic extraction on the output rate of rapeseed oil and rapeseed protein, adopting the rapeseed emulsion which was treated by optimized technology parameter . The result showed that pH and temperature had important effect on the output rate of fats and protein, but the extracting time had no obvious effect.The RSA being adopted to the optimization experiment, we got the most proper conditions of water-extraction after enzymatic extraction: the ratio of solid to liquid was 1:6.5, pH was 9.6, temperature was 52C, extraction time was 98 min.During the research on the ultrafiltration technique of the rapeseed protein extraction liquid, we used ultrafiltration to treat the rapeseed protein extraction liquid made by the aqueous enzymatic extraction and undertook the parameter research of the rapeseedprotein ultrafiltration. We found that the ultrafiltration could be operated at a comparatively high Jv with the operation pressure of 0.20-0.30 Mpa, temperature of 50C, the liquid pH of 9-10 and the discontinuous and circulatory cleaning of the rapeseed protein extraction liquid with weak lye and Alcalase during the ultrafileration process.Extracting the oil and fat and protein of the rapeseeds with aqueous enzymatic extraction under optimal conditions, separating the rapeseed protein from the liquid with ultrafiltration technique, the rapeseed oil extraction rate should be 92.7% and the protein extraction rate 82.3% and the content of rapeseed protein in the product exceeded 90%.It was easy to prove that this method was better than conditional aqueous extraction. At the same time, the content of ITC and the OZT could not be found . But how to reduce the using cost and how to make this technology on an industrial scale need further study.