Refining process of walnut oil refining equipment:
(1)Degumming:main equipment:hydration tank
In edible oil,if the phospholipid content is high,it is easy to bubble,smoke,overflow pot when heated,and phospholipid oxidation at high temperature makes the oil brown,affecting the flavor of fried food.To remove phospholipids,mucilage,resins,proteins,sugars,trace metals and so on in wool oil,hydration method and acid refining method are generally used.
(2)Deacidification:main equipment:alkali refining tank,washing tank
Free fatty acids affect the stability and flavor of oil.Free fatty acids,acid pigments,sulfides,insoluble impurities and trace metals in oil were removed by means of edible alkali neutralization.
(3)decolorization:main equipment:dehydrating tank,decolorization tank
Crude oil contains chlorophyll,carotenoids and other pigments,chlorophyll is a photosensitizer,affecting the stability of oil,and other pigments affect the appearance of oil,adsorbents can be used to remove clay,aluminum silicate,activated carbon and other adsorbents,to remove all kinds of pigments,colloid,oxide and so on.
(4)Deodorization:main equipment:deodorization tank,deodorization tower
There are some unwanted odor substances in oil,which mainly come from oxidation products of oil.Using vacuum distillation method,and add citric acid,chelate excessive metal ions,inhibition of oxidation using vacuum stripping principle,oil in the removal of low molecular odor substances,free fatty acids,single glyceride,glyceride,sulfide and pigment thermal decomposition products.
(5)Dewaxing:main equipment:crystallization tank,plate and frame filter,refrigerator,etc
The wax fat in vegetable oil is mainly contained in seed coat,shell and germ of vegetable oil.Its solubility in oil is very low,and its melting point is high(78-82 degrees),so it can not be absorbed by human body and difficult to be saponified.Oil dewaxing is a process in which wax with high melting point and solid fat with high melting point are separated out from oil by cooling and crystallization,and then removed by filtration or centrifugation.Special reminder:some precious oils do not contain wax.The dewaxing process is mainly to increase the viscosity of oils by cooling,filter out the trace solids mixed in the oil,and ensure the appearance of bottled oil.