Refined rapeseed oil refining process
Rapeseed oil is a semi-dry oil containing erucic acid. Except for canola oil, the other varieties of rapeseed oil contain more erucic acid, which accounts for 26.3% to 57% of the fatty acid composition. High erucic acid oil is less nutritious than low-erucic acid oil, but is particularly suitable for industrial oils such as marine lubricants and tires. In the process of oil production, the mustard seed is hydrolyzed by the enzyme of mustard, forming some sulfur-containing compounds and other toxic components.This affects the quality of the oil. The general smelting process has a very low removal rate of sulfides. Therefore, edible rapeseed oil should be refined.
Palm oil refining process
Palm oil is obtained from palm fruit pulp. Its fatty acid composition accounts for 40% to 50% of saturated acid, 80% of which is palmitic acid, oleic acid is the main unsaturated acid, followed by linoleic acid.Because palm fruit is decomposed by lipolytic enzymes before harvesting and oil production, combined with processing methods and storage and transportation conditions, the free fatty acid content of palm oil is comparatively high. It is generally about 10%, and high level is more than 30%.
The impurity filtration temperature is not lower than 50 ° C, and the oil content after filtration is not more than 0.2%. Interval break neutralization initial temperature 30 ~ 35 °C, final temperature 60 ~ 65 °C, lye concentration 16 ~ 18 °Bé, excess alkali accounted for 0.2% ~ 0.3% of oil, neutralization time l h or so. The concentration of continuous neutralization lye is 20-28 °Bé, the excess alkali accounts for 10% ~ 25% of the theoretical alkali, and the de-soaping temperature is 70 ~ 95 °C. The drum washing water is 20~25L/h, the oil inlet pressure is 0.l~0.3MPa, and the oil back pressure is 0.l~0.15MPa. The de-soaping oil washing temperature is 85 to 90 ° C, the washing water addition amount is 10% to 15% of the oil amount, and the residual soap of the washing oil is not more than 50 ppm. The decolorization temperature of solid fat and liquid oil is 105-110 °C, the absolute pressure of operation is 2.5-4.0 kPa, and the time is 15 min. Activated clay added 3% of oil. Distillation deacidification and deodorization temperature 240 ~ 250 °C, operating absolute pressure 0.2 ~ 0.4kPa, time is 80 ~ 100min. The initial temperature of the cooling crystallization temperature is 70-80 ° C, and the temperature is gradually cooled to about 20 ° C for 24 h. The temperature difference between the cooling water and the oil is 5-8 ° C. The filtration pressure during separation shall not be high.