The Study On Aqueous Enzymatic Preparation Of Rapeseed Oil

This paper studied the process of aqueous enzymatic preparation of rapeseed-oil. The paper included three parts as follows:The research of the pretreatment aqueous enzymatic preparation of oil, the research of enzymatic method and enzymatic factor and the demulsification research .The research of the pretreatment aqueous enzymatic preparation of oil showed that the highest quantity could be obtained in the condition of the heating time of two hours, the heating temperature of 90℃ and the grinding time of 15 minutes.The study on the different enzymatic method showed that the best method should include the following step: enzymatic degradation, extracting, re-enzymatic degradation and re-extracting.The effect of aqueous enzymatic preparation of oil was influenced by some factors. The output of the oil were determined by the following factors: the pH of the system, the ratio of water to rapeseed, the temperature, the degree of grinding and the content of enzyme.The degree of aqueous degradation of protein reached the peak when the temperature of aqueous degradation was 50℃, meanwhile, the degree of oil production reached the peak. The degree of oil production also reached the peak of 84.3% when pH was 6.0, at which the degree of hydrolysis was 13.79%. Then the degree of hydrolysis increased gradually with the increase of pH and reached the peak when the pH was 7.0. After then, the degree of hydrolysis decreasedgradually. However the production of oil decreased with the increase of pH.The degree of hydrolysis increased with the decrease of the concentration of rapeseed or the increase of the ratio of water. When the ratio of rapeseed to water was 1:5? the degree of hydrolysis and the production of oil reached the max value. Both the degree of hydrolysis and the degree of oil production increased gradually with the increase of the dosage of the enzyme. When the dosage of enzyme was 10ml, both the degree of hydrolysis and the degree of oil production reached the max value. Both the degree of hydrolysis and the degree of oil production also increased gradually with the increase of the degree of the grinding. When the degree of the grinding was 200mesh? both the degree of hydrolysis and the degree of oil production reached the max value. However, the production of oil have no obviously difference when the degree of the grinding was in the range of 160meshs to 200meshs. So the degree of the grinding in the range of 160mesh to 200mesh could be considered in the production.When the rapeseed is proceeded by combining physical grinding with enzymatic degradation, the molecule of oil and protein will disperse into aqueous phase and form the emulsified oil. Because of the polarity and the stickiness of rapeseed-oil and the exist of hydrophilic and lipophilic protein, the oil and the water will mixed and it was difficult to separate them thoroughly and form emulsified oil. For the aim of usage, preservation and the quality of the rapeseed-oil. it was necessary to get rid of the water and the protein in the emulsified oil. The study on demulsification showed the centrifuge, the heating, the adjustment of pH and the extraction were helpful for the emulsification.Meanwhile, the best effect could be reached when the extraction was used.