Study On The New Refined Prosess Of Soybean Oil

Edible vegetable oil has been an indispensable necessity in our daily diet. Withthe rapid economic development and the people’s improving living standard day byday, the daily consumption of vegetable oil has also increased substantially, so moreand more attention has been paid to the quality of the vegetable oil. At the same time,it also put forward higher requirements for China’s oil refining industry. In this study,the degumming and decolorization processing of soybean oil refining processing wereimproved on the basis of the traditional soybean oil refining processing and previousstudies；The phospholipase Lecitase Ultra was applied in soybean oil degumming;The effects of ultrasound on removal of nonhydratable phospholipids byphospholipase Lecitase Ultra was studied;silica gel was used in the decolorization ofsoybean oil with combining silica gel and clay in the processing of soybean oildecoloration test to explore the influencing factors for oil bleaching process.The mainstudies are as follows:（1）Through the single-factor test, the effect of enzyme concentration, reactiontime, reaction temperature, pH, water content on removal of nonhydratablephospholipids of soybean oil by phospholipase Lecitase Ultra were studiedrespectively. On the basis of single factor, the enzyme concentration, reactiontemperature, hydrolysis time, the pH value were selected as independent variables,then, according to central composite design principle, the phosphorus content indegummed oil was selected as response value, the test of removal of nonhydratablephospholipids in soybean oil by phospholipase Lecitase Ultra was designed byutilizing the response surface methodology. The software Expert Design7.0Trial wasused for data processing, the quadratic polynomial regression equation betweenphosphorus content （P） and the enzyme concentration （X₁）, reaction time （X₂）, thereaction temperature （X₃）, pH value （X₄） was obtained:P=316.08275+151.73333X₁+3.76867X₂-3.86137X₃-96.96733X₄-14.00000X₁X₂+5.00000X₁X₃-210.00000X₁X₄-0.038000X₂X₃-2.02000X₃X₄+0.08000X₃X₄+6907.50000X₁²+1.138000X₂²+0.037430X₃²+11.51200X₄² Through the equation,the best combination parameters of removing the nonhydratablephospholipids by the phospholipase Lecitase Ultra was obtained as follows: enzymeconcentration0.045%, reaction time of3.5h, reaction temperature44.0°C, pH value4.8. The experiments had been done according to this condition, the averagephosphorus content got from the parallel three times experiments was6.2mg/kg, thedifference between predictive and experimental value was just only0.34607mg/kg.（2） Alkali refined soybean oil was used as raw material in decolorization to studythe effects of ultrasound on removal of nonhydratable phospholipids by phospholipaseLecitase Ultra. The results show that moderate ultrasonic treatment can improve thecatalytic activity of phospholipase Lectase Ultra, the speed of enzymatic reaction washeightened, thus shortening the reaction time; Ultrasonic wave treatment increased theoptimal reaction temperature of phospholipase Lectase Ultra significantly, but theoptimum pH value didn’t change; Compared with the conventional enzymaticreaction, the water in ultrasound-assisted reaction system has been "fully exploiting"and become more "effective".（3） Silica gel and white clay were applied together in soybean oil decolorizationtest to study the various effective factors on oil bleaching processing.The optimumlevel of various factors were determined: added amount of silicone0.15%,reactiontemperature90℃,reaction time25min,amount of clay1.3%.And the oven method wasused to evaluate the storage stability of the bleached oil.The results showed that thebleached oil by silica gel-clay processing was not easy to get the color reversion,andhad better storage stability.