Highly Selective Enrichment Of Rapeseed Protein

Rapeseed Prepress-solvent Extracted Meal，the by-product from the mostwidely applied oil-producing process in China is a vegetable protein resource withenormous potential．To achieve reliable assessment on the ture protein content inrapeseed protein materials or products and realize the value-added utilization ofrapeseed protein products，the following studies were carried out．1To achieve reliable assessment on the ture protein content in rapeseedprotein materials or products，a highly selective determination method involvingsteps of sample fraction and protein quantification was established．Samples wereextracted with acidified aqua acetone and subsequently with boiling water toremove the non-protein nitrogen (NPN)，and then the soluble protein in liquidfractions was determined by Bradford method while the insoluble protein in solidfraction was determined by Kjeldahl method，thus the combination of protein inboth fractions represents the true protein in sample． The method has showndesirable capability of anti-interference on both endogenous NPN (includingglucosinolates and sinapine) and exogenous NPN (including nitrate， ammoniumsalt， melamine and urea)．In addition，the coefficient of variation was less than2．83%and the recovery rate was within the range of95%~96%．Due to theanti-interference capability on various NPN and compatibility on proteinsolubility，this method could be applied widely in determining various types ofplant ture protein and as reliable tool for adulteration identification or qualityevaluation．2In order to solve the problem of low selectivity in the preparation o frapeseed protein concentrate． A new preprocess of rapeseed prepress-solventextracted meal pretreatment and separating the rapeseed hull and rapeseed kernel inthe wet environment was established．Then combined with pickling detoxificationtreatment to preparate the high quality rapeseed protein concentrateproducts．Rapeseed prepress-solvent extracted meal was dissolved by phosphate toliquefy the rapeseed kernel． Then added acetone to diluted and filtered thesuspension．Through these processes the rapeseed kernel would be separated．Theoptimum process condition was controled the solid to liquid ratio is7:1(massratio)， temperature50℃and time90minutes， added acetone to diluted and thenfiltered with40aperture． The sieving part was washed by acetone and desolventized， then washde by pH4hydrochloric acid solution．Through the aboveprocesses，we can get the rapeseed protein product with the yield was61.12%，thepurity was58.15%respectively (dry basis)．The removal rate of glucosinolate，totalphenol and phytic acid reached95.90%，95.90%and98.60%． Respectively，thequality of the product can reached the quality of the rapeseed proteinconcentrate．The rapeseed protein concentrate on the process has higher watersolubility than the original protein in rapeseed meal which can continue topurificate for the high value of rapeseed protein products．3In order to solve the problem of the low Nutritional potency， Poorpalatability and colour with rapeseed protein products．We inspected the influenceof environmental parameters on rapeseed protein and polyphenol solid-liquid phaseequilibrium With purified rapeseed protein and polyphenol as samples．Through theexperiment of dissolution characteristics of rapeseed protein with the concentrationof phenol and the experiment of the interactions of rapeseed protein and phenolunder the condition of different PH，salt concentrations．We can obtained thatphenolic acids in rapeseed polyphenols and tannins both can coprecipitated withrapeseed protein．The coprecipitation was more obvious if their concentration werehigher and the coprecipitation was weakest if the phenol concentration was0.77mg/ml．When the pH of the solution is pH4.0，not only the solubility ofRapeseed protein is minimum，but also and coprecipitation of tannin and rapeseedis weakest and the separating degree is largest，which is good for the enrichment ofrapeseed protein．But at the pH12.0，all cases were on the contrary．Added1%NaCl to the solution would be conducive to further enhance the degree ofseparation of the rapeseed protein and phenol．In the extraction of rapeseed proteinprocess and enrichment of rapeseed protein process，solid-liquid ratio，pH and saltconcentration were all impacted the interactions of rapeseed proteinand phenol．So to optimize these parameters will be good for selective enrichrapeseed protein，and reduce the phenolic residue．...