Study On Preparation Of Pressed Flaxseed Oil And Adsorption Refining

Currently hot pressing and conventional refining is widely used in processing flaxseed. But this method doesn’t take characteristics of oilseeds and crude oil into consideration, meanwhile has the disadvantage of low extraction rate of oil, high energy consumption, excessive refining and so on. Based on those issues, we take flaxseed as raw materials, and carries out a research on the process for pressed oil and refining raw oil by solid sorbents.The main results of the paper are as follows.1. Taking flaxseed as materials, we study the effect of three factors(temperature, time and moisture content) on residual oil of cake and quality of oil. The results show that an appropriate temperature, treating time and moisture content of oilseeds, can improve the oil yield effectively and make the oil rich in fragrance; At the same time, it’s not affect the content of vitamin E and sterols; This suggests that for the nutrition of flaxseed oil, there isn’t a significant difference between hot pressed oil and cold press oil; Also get the optimal process parameters of flaxseed oil temperature 160 ℃, treating time 30 min, moisture content 2%.2. Taking diatomite as raw material, we firstly study the technique to prepare and use deacidification agent, and the optimization of process parameters is alkali concentration 25%(w/w), solid-to-liquid ratio 1:5(w/w), processing time 40 min, treatment temperature 70 ℃; the optimization parameters for use is time 25 min, temperature 60 ℃; we also obtain the relationship between acid value and amount of deacidification agent by different acid value oil; deacidification agent can effectively decrease the acid value and almost has no influence on main physicochemical properties of oil; The deacidification agent of its materials is in the list of food additives standard(GB2760-2011), meanwhile the deacidification method can avoid using of water, reduce energy consumption and environmental pollution, so it is suitable for use in oil industry.3. By comparing adsorption ability of several common solid adsorbents on CLP-E in flaxseed oil, we find activated clay is the best; but activated clay bring about bad odors, in order to weaken or even eliminate odors from bleaching, we treat activated clay with alkaline, and obtain the best alkaline p H of 7.9; alkaline clay adsorbents for the adsorption of CLP-E is optimized to obtain the best parameters for temperature 60 ℃, time 20 min. Under process conditions, the bitter taste of flaxseed oil have improved, meanwhile the adsorbent have no significant effect on main physicochemical properties of flaxseed oil; The raw materials of alkaline activated clay can meet the requirement of processing aids in edible oil industry; it also has the advantage of low cost, simple process, etc.4. Using deacidification agent and alkaline clay adsorbent, we conduct a study to refine flaxseed oil by fractional step and coupling step. The results show that both the two methods can lower acid value and reduce bitterness of flaxseed oil, and the oil can change from 2nd grade to 1st grade; from physical and chemical and nutrition indicators point of view, there is no obvious difference between two refining process, but from the simplicity of the process point of view, coupled refining process is more simple, cost savings, so it is much more suitable for refining for flaxseed oil.