The steps in the oil extraction and refining process include degumming, deacidification, dehydration, decolorization, deodorization, and dewaxing. Dewaxing, as the final step in oil refining, plays a crucial role in the entire oil extraction process. Crystallization is a key process in the dewaxing of edible oil. During dewaxing, the deodorized oil is sent to the crystallization tank of the dewaxing equipment. Chilled brine is circulated through the coils in the crystallization tank, causing the oil to slowly crystallize and form nuclei. As the cooling process continues, the nuclei gradually grow into crystals and slowly precipitate. The crystallized oil is then sent to a filter for filtration, resulting in the final product oil.

Factors influencing wax crystallization in edible oil dewaxing

1. Cooling Rate:

The cooling rate significantly affects wax crystallization. If the cooling rate is too fast, it may lead to the formation of oil-wrapped wax structures, which can reduce the yield of dewaxed oil and affect the quality of the final edible oil. Therefore, it is necessary to control the cooling rate reasonably during dewaxing to ensure that the wax crystallizes evenly and slowly.

2. Crystal Growth Time: 

Crystal growth is an important stage for the growth of wax crystals. The length of the crystal growth time directly affects whether the wax can be completely separated from the oil. If the crystal growth time is insufficient, the wax in the oil may not be fully removed, affecting the quality of the oil. Therefore, it is necessary to ensure sufficient crystal growth time during dewaxing to ensure that the wax can fully crystallize and separate.

3. Oil Quality: 

the quality of the refined oil also has an important impact on the dewaxing effect. If the oil quality is poor, such as containing more impurities or undesirable components, it may affect the oil yield and the quality of the final product oil during dewaxing. Therefore, it is necessary to fully refine the oil before dewaxing to improve its quality and reduce the difficulty of dewaxing.

4. Temperature Control: 

Temperature is one of the key factors affecting wax crystallization. During dewaxing, it is necessary to control the temperature reasonably to ensure that the wax can crystallize at an appropriate temperature. If the temperature is too high or too low, it may lead to poor wax crystallization, affecting the dewaxing effect. Generally, the temperature during the crystal growth stage should be controlled between 15-25°C to ensure that the wax crystals can fully grow.

In summary, the factors affecting wax crystallization during the dewaxing process of edible oil mainly include cooling rate, crystal growth time, oil quality, and temperature control. To achieve good dewaxing results and high-quality edible oil, these factors need to be strictly controlled and managed during the dewaxing process.