Research On Aqueous Enzymatic Extraction Of Protein And Oil From Cold-press Rapeseed Cake

The rapeseed protein was not denatured after cold pressed,and the content of rapeseed protein increased. But it contained many anti-nutrition factors.. It can be improved in its nutritional and commercial values with aqueous enzymatic extraction method. In this study,the technique of aqueous enzymatic extraction was applied to deal with cold-pressed rapeseed cake to develop a new process for extraction protein and oil from rapeseed. The study also aims to provide a new approach to making good use of cold-pressed rapeseed cake. The physical and chemical characteristic of rapeseed protein and oil extracted by aqueous enzymatic extraction method with conventional technics was compared.1. Enzyme selection and confirmation of the condition of enzyme reactionThe extraction protein and oil from cold-press rapeseed cake with three enzymes was analyzed, which were protease,viscozyme and pectinase, and the double-enzyme system based on the result was put forward. The results were as follows: the double-enzyme got maximal extraction rate,viscozyme got the minimal one, and protease got the mid one,which results with enzymes better than water-extraction, besides the effect of pectinase was not obvious in the same reactions. At the same time,it discussed the effect of enzyme dosage,solid-to-liquid ratio,operating time, materiel size and milling speed.2. Optimization of the technique of aqueous enzymatic extraction protein and oil from the cold-pressed rapeseed cakeThe response surface test of 3 factors(enzyme addition quantity,enzymatic reaction time, ration of stuff to solvent) 3 level with SAS software based on single factor test to optimized technique condition was designed. The optimum extracting condition was attained by response sruface test as enzyme addition quantity 1%, enzymatic reaction time 80min, ration of solvent to stuff 7,with the product of 82.41% protein content. The extracting rate of protein was 82.68% and oil was 72.03%.3.The technique of traditional extraction protein from the cold-pressed rapeseed cake It has been discussed in this study on the technique of traditional extraction from the cold-pressed rapeseed cake. The optimal extracting condition was attained by orthogonal experiments as temperature 60℃, pH11,ration of stuff to solvent 1:15, extraction time 30min.The extraction rate of protein was 87.69% and the product of 77.45% protein content.4.Studies on the functional properties of enzyme extracted protein and analysis of quality of rapeseed oilFunctional properties of enzyme extracted protein and alkaline extracted protein from rapeseed has also been studied in this paper. Enzyme extracted protein was better alkaline extracted protein in emulsibility,emulsion stability,foaming ability,water-holding and oil sorption,which made it suitable in meat product and milk product.By comparing the physical and chemical properties,it was found that rapeseed oil extracted by aqueous enzymatic method achieved the standard of four-grade rapeseed oil.