The Studies On Oryzanol In Rice Bran Oil With Physical Deacidification

In this thesis, the project studied the impact of process conditions of single solventdeacidification, mixed solvent deacidification, and deacidification with steam distillation onthe content of oryzanol in rice bran oil, as well as the change of the FFA removal rate and theloss rate of neutral oil change, using physical methods of solvent extraction deacidificationand deacidification with distillation, based on a high acid value of crude rice bran oil as a rawmaterial. Also, the process was optimized to explore the process conditions for rice bran oilphysical deacidification.Methanol and ethylene glycol were selected as the single solvent for the rice bran oildeacidification, according to the polarity of the organic solvent. And extraction times, materialdissolved ratio of oil and solvent, extraction time, extraction temperature, stirring speed,solvent pH value as influencing factors，the content of oryzanol, the FFA removal rate and theloss of the neutral oil as response values, the two solvents were screened. The results showedthat methanol was the ideal single solvent of rice bran oil deacidification.The deacidification process of rice bran oil with methanol was optimized byDesign-Expert8.0.5.0. The mathematical models of the key factors affecting the oryzanolcontent of rice bran oil, the FFA removal rate, and the loss rate of neutral oil were established.The result showed that the optimum conditions were the ratio of oil to solvent (g: ml),1:2.3;extraction time12min; extraction temperature26℃, stirring speed1200r/min, solvent pHvalue4and3times of extraction. Under this conditions, the content of oryzanol was1.67%, theremoval rate of FFA was84.95%and the loss rate of neutral oil was15.37%.95%ethanol, n-propanol–water, isopropanol–water, acetone–water and methanol-acetone were selected as the mixed solvent for the rice bran oil deacidification, according tothe polarity of the organic solvent. And taking times of extraction, material dissolved ratio ofoil and solvent, extraction time, extraction temperature, stirring speed, solvent pH value asinfluencing factors，the content of oryzanol, the FFA removal rate and the loss of the neutraloil as response values, above solvents were screened. The results showed that95%ethanol was the ideal rice bran oil deacidification mixed solvent.The deacidification process of rice bran oil with95%ethanol was optimized byDesign-Expert8.0.5.0. The mathematical models of the key factors affecting the oryzanolcontent of rice bran oil, the FFA removal rate, and the loss rate of neutral oil were established.The result showed that the optimum conditions were the ratio of oil to solvent (g: ml),1:1.5;extraction time20min; extraction temperature20℃, stirring speed1200r/min, solvent pHvalue6and2times of extraction. Under the conditions, the content of oryzanol was1.49%, theremoval rate of FFA was93.05%and the loss rate of neutral oil was17.93%.Rice bran oil deacidification with steam distillation were studied while time andtemperature as influencing factors，the content of oryzanol, the FFA removal rate and the lossof the neutral oil as response values. The results showed that, when the deacidificationtemperature was250°C and deacidification time was90min, the oryzanol content of rice branoil was1.90%, the FFA removal rate of rice bran oil was89.09%.