1. The saturated fatty acid content of some oils and fats at high temperature is high. When the temperature is high, it is clear and transparent. When the temperature is reduced, saturated fatty acids with high molecular mass may change from the liquid state to solid state and precipitate from the oil. When the amount of precipitation is small, it will affect the transparency of the oil and fat, making the oil look hazed, that is It became cloudy when you went up. As the temperature continues to drop, the amount of precipitation will increase, and solid fatty acids will accumulate and sink to the bottom. At this time, there will be obvious solid-liquid stratification of oil until all oil and fats become solid. Common animal oils and fats are basically solid at room temperature, and some vegetable oils and fats will also have solidification and precipitation at lower temperatures. For example, peanut oil begins to solidify and precipitate at about 10℃.
2.In principle, refined refined oil is almost water-free, so it is clear and transparent. After entering the refined oil tank, it is affected by the storage environment, such as the water in the tank that has not been cleaned up, or the humid air enters the tank, and the moisture in the air condenses and enters the refined oil, etc. Moisture will have a great impact on the transparency of oil. After communicating with netizens, according to their description, the reason why the oil becomes cloudy may be caused by the humid air in the tank.
3. The wax content of different varieties of oils and fats has different wax content. The wax content of some oils and fats is very low, and the impact on the transparency of oils and fats is negligible, such as our common soybean oil. However, the wax content of some oils is relatively high. It is cloudy at room temperature. The oil must be dewaxed to become clear and transparent, such as rice bran oil. We once refined a batch of a certain vegetable oil. No matter how refined the indicator of transparency was unqualified, because of its high wax content. In addition to the above three cases, oil oxidation deterioration, phospholipid content, other impurities, etc. may also cause oil to become cloudy.
