The Improvement Of Corn Oil Refining Process

Crude corn oil is squeezed from corn germ.It is a kind of tan vegetable oil,whichcontaining impurities, prone to turbidity, and have a unpleasant smell, therefore, crudecorn oil can not be directly eated. After degumming, deacidification, bleaching,dewaxing, deodorization process the crude corn oil will become pale yellow,Transparent clear and stable. In this paper, the various of corn oil refining process hasbeen researched, and the best parameters of refining process has been determinedthrough single factor and orthogonal experiments. The results of the study are asfollows:1. According to the corn oil refining process, corn oil degumming process werestudied at first.The best parameters of corn oil degumming process was obtained asfollows: Phosphate0.3%, water0.3%, the temperature is75℃, the hydration time of40min. Under this condition of the degumming, degumming effect is best, phosphatidecontent in corn oil dropped to0.042mg/g, oil yield was95.08%.2. The optimal process parameters of deacidification was obtained as follows: thetemperature is85℃, NaOH mass fraction is10%, super alkaline is0.25%(totalquantity is3.6%),deacidification time is30min. Degumming corn oil under thecondition of best deacidification parameters, the corn oil acid value decrease to0.31mg/g, acid oil yield was95.79%.3. The best proportion of mixed decolorizing agent for activated carbon andactivated clay is1:10. Decolorizing optimum technological parameters was obtained asfollows: temperature is110℃, decoloring agent2.5%, reacting25min. Though thiscondition the corn oil become light yellow, no peculiar smell, and the decoloring oilyield was95.69%.4. The optimum parameters of dewaxing was obtained as follows: reacting13h,crystallization temperature is15℃, diatomaceous earth content is3.5%. Afterdewaxing oil yield was93.03%.5. The optimum parameters of deodorization is as follows: the deodorization0.133kPa vacuum degree, temperature250℃, deodorization time is2h. Under thiscondition, the free fatty acids of corn oil dropped to0.021%, POV is0.7mmol/kg, andthe odor substances of corn oil was substantially removed.