Prief Introduce of Rice Bran Oil Extraction Technology
Fresh generally contain 18% ~ 25% of rice bran oil.The oil content depending on the type, degree of rice peeling of rice, storage conditions and storage time.In order to maximize the extraction of the lipid composition in rice bran, rice bran can be used rice bran oil extraction process or rice bran extrusion process.Rice bran oil extraction equipment two process adopts hexane as extraction solvent,Rice bran oil extraction temperature is in commonly 50 ℃ ~ 60 ℃, solvent n-hexane is inflammable, explosive, especially at high temperature is more conducive to production and processing operation and storage.At the same time, the leaching equipment phospholipids, pigment, free fatty acids content in rice bran oil is higher, is not conducive to oil processing and storage.To this end,Food court after milling machine using ordinary valley exuviate to 40 mesh sieve screening of rice bran was studied: rice bran oil at room temperature balance leaching can quickly better, using hexane extraction under 22 ℃ 1 g rice bran, leaching equipment the number of rice bran oil determination after 10 min, at the same time for different number of rice bran with fixed volume of solvent leaching grease is also studied.Studies have shown that within 1 min dipped 90% fat, or extend the leaching time quickly reaching equilibrium after 10 min, oil production rate increase is very few, up to 94%.In addition, the effect is not as good as 1 min rice bran leaching leaching effect of soybean powder (oil production rate 98%), but its effect can be compared with CO2 supercritical fluid extraction rice bran [2].Leaching rate is relatively lower than soybean powder, rice bran could be more oil soluble impurity is contained in rice bran oil, such as high melting point of wax and saturated fat, such as small solubility at low temperature, viscosity, extraction diffusion is slow, affect the spread of solvent and oil, solvent even more than still can not obviously improve the oil yield.
Quick balance leaching method oil yield reached 90% ~ 97%.1 min fast balance leaching rate close to the reported high temperature solvent leaching rate, but less than Goldfisch leaching rate.Explosion problems exist in hexane as solvent leaching, volatile And of high boiling point, harmful to human body."Clean Air Act" by the United States in 1990 as a source of air pollutants.To this end, oil solvent leaching equipment new appear constantly.Choose solvent such as isopropyl alcohol as a new leaching solvent for vegetable oil in order to avoid the problems caused by hexane.Leaching equipment application of hexane and isopropanol as solvent at room temperature balance leaching rice bran.To yield efficiency and leaching oil oxidation stability is studied.
Adopted by 0.45 mm mesh, water cut 13% of the fresh rice bran study shows that using hexane and isopropanol leaching 10 min of rice bran oil yield are shown in table 1.Isopropyl alcohol leaching rice bran oil yield the same as the f alkanes, after 10 min isopropyl alcohol leaching by the amount of oil as to control the amount of oil.
Isopropyl alcohol leaching results with CO2 supercritical fluid extraction yield 98% than rice bran oil grease.Oil leaching equipment using hexane and isopropanol as solvent at room temperature balance leaching of rice bran oil get free fatty acid (FFA) content and phosphorus content is the same.Change the solvent ratio, and can't significantly change the content of FFA,And solvent leaching and Goldfisch at room temperature, the difference of phospholipid content is very small, but the phospholipid content is significantly higher than previously reported by the water content of 10% of the rice bran of phospholipid content of rice bran oil.High water content in rice bran (13%) can lead to high leaching oil phospholipid content.
