Transesterified Soybean Oil Technology And Establishment Of Rapid Determination Of Phytosterol

Phytosterol has a very important physiological value which exists in plant cells, and it is widely used in medicine, food, chemical, plant gene engineering field. In this research transesterified soybean oil with high content of phyotsterol had been analysised by using the UV spectrum method and gas chromatography,to establish a method which is fast, simple, accurate and low-cost for the determination of phytosterol content in functional vegetable oil with high content of phyotsterol.Since the discovery of phyotsterol, its quantitative analysis has been improved, and there are both advantages and disadvantages. There is no national standard method for determining content of phytosterol in vegetable oil. This study primarily established the UV spectrum method to determine the content of phytosterol in transesterified soybean oil, learning from the methods that determining the content of phytosterol in food and edible oil. Discussed and determined the conditions of coloring reaction and the best measurement parameters.Through a comparative analysis of results, determination of the UV spectrum method is closed to gas chromatography, it is a convenient, quick, accurate method that determining the content of phytosterol in transesterified soybean oil. The UV spectrum method can provide theoretical basis and technical parameter for the transesterification reaction process, and fills the blank of daily monitoring method in determine functional vegetable oils added photosterol. The main content of this research:(1) Establishing of gas chromatographyTransesterified soybean oil were analyzed using HP-5capillary column (30m X0.32mm×0.25u m), the experimental results show that this method can be used for quantitative and qualitative analysising physterols in transesterified soybean oil, overcoming derivatization faults by gas chromatography. Response time is less than18min, and every phytosterols can be separated.(2) Establishing and evaluation of the UV spectrum methodDetermination conditions of the UV spectrum method:the UV spectrum is generated on the reaction of phytosterol and iron vitriol reagent, the maximum absorption wavelength of the UV spectrum method is564nm, standard curve of phytosterols. Discussed and determined the conditions of coloring reaction and the best measurement parameters. The optimal parameters: coloring agent dosage2mL, chromogenic agent composition ratio2:8, coloring time30min, coloring temperature20℃. Pretreatment of transesterified soybean oil:the conditions of saponification method for extracting phytosterol were optimized through single factor and orthogonal test. Optimal extraction parameters:saponification time30min, saponification temperature80℃, concentration alkali1.5mol/L,solid-liquid ration0.05g/mL.The results of the UV spectrum method is higher than gas chromatography by0.14%, the maximum absolute error of the UV spectrum method is0.21%, average higher by0.14%; the maximum relative error is3.7%, average higher by2.95%. There is no relationship between the difference range and the content of physterol, determination of the UV spectrum method is close to gas chromatography. Determining precision of the UV spectrum method is high, the average recovery rate is98.61%, the relative standard deviation is0.57%, and the measuring result is accurate and reliable.(3) Preparation of transesterified soybean oil with high content phytosterolUsing the UV spectrum method to monitoring the content of phytosterol in transesterified soybean oil, optimal processing technology has been determined through response surface design experimental, phytosterol add volume5%, reaction temperature70℃, enzyme dosage1.02%, reaction time3h. The actual rate of esterification is87.81%, and the relative error is0.35%between the actual and predicted values which is88.16%, so the validity of the mode is confirmed by experimental values good fitting to the predicted values. The significance of this research:Through systematic research, a convenient, fast, accurate method of determining content of phytosterol in transesterified soybean oil is set up. It plays an important role in the development of functional vegetable oils added phytosterol, and providing fast and convenient monitoring means for research and industrial production.