Cottonseed Oil Refining

Cottonseed oil appears darker red than other oils and requires refining to make it safe for human consumption. Despite the high content of essential fatty acids it contains, it should be mixed with animal fat before consumption. Unlike peanut and rapeseed oils, cottonseed oil cannot undergo strong-flavor processing. Instead, it must be refined by refining oil equipment to remove impurities, especially gossypol. The presence of gossypol in cottonseed oil can cause palpitation, shortness of breath, fatigue, and dizziness when consumed. Additionally, it can damage the skin and decrease sweating abilities. Consistent consumption of crude cottonseed oil can impair spermatogenic cells, leading to infertility.

To remove gossypol, cottonseed oil is refined using alkali refining equipment. The primary aim of this process is to eliminate gossypol, free fatty acids, phospholipids, and some impurities and pigments. The lye is first prepared and measured before being added to the oil. Stirring should continue for five to ten minutes while adding the lye. The stirring frequency should be 60 revolutions per minute. After three minutes, stirring can continue even when the soap and oil have separated. Increasing the temperature to around 75 degrees would cause separation between the soap stock and oil. The soap will settle quickly, achieving the goal of gossypol removal. It's worth noting that while raising the temperature, the stirring frequency should drop to 30 revolutions per minute.