Quality indicators of free fatty acids:
Since palm oil is refined in a high-temperature vacuum process, steam can take away almost all free fatty acids, so free fatty acids are the best quality and hygiene indicators for evaluating palm oil. The lower the value, the higher the degree of refining, and the harmful Substance is also lower. In the hundreds of batches of palm oil that have passed our port inspection in recent years, the free fatty acid results are basically: palm omitin, palm oil, and palm kernel oil are less than 0.1%, and palm stearin is less than 0.2%.
Sometimes it is detected that the free fatty acid exceeds the standard. After analysis,
there are the following reasons:
①Transportation under the sun exposure, especially the sudden thunderstorm after high temperature exposure in summer (common in Southeast Asian climate) can make the free fatty acid rise sharply, once it rises, it is difficult to drop back.
②If only the bottom layer of the container (big wheel or iron drum) is sampled, the free fatty acid test result will be high, because the bottom layer contains more palm stearin. Therefore, a mixed sample should be taken from the top, middle and bottom according to the standard in a certain proportion.
③Because palm cabinet oil products often need to be heated when testing in the laboratory, and the value of free fatty acids is often artificially increased due to sudden heat, which affects the test results. The detection method of acid value is the same as that of free fatty acids. Conversion relationship: acid value × 0.453 = free fatty acid (calculated as palmitic acid, %) In addition, when the detected free fatty acid content is low and the water content is high, pay attention to whether there is water in the container (iron drum or cabin) .