The Research And Design Of Defluoridation Process Of Oil In Antarctic Krill (Euphausia Superba)

Antarctic krill (Euphausia superba) is the largest single biological resources inmulti-cellular organisms. It has a big biomass energy of about five hundred milliontons, which can be said the most successful specie evolved on Earth. The standingcrop is estimated to be6.5x108~1.0x109tons. About150million tons of Antarctickrill were captured every year. Obviously, it is a huge fish resource in the world.Antarctic krill is rich in nutrition and has a high protein content. Especially, the oil isrich in unsaturated fatty acid, phospholipids, astaxanthin and other nutrients. They arebenefit for anti-aging and the health of cardiac vessel. The study on the Antarctic krilloil is relatively scarce in our country, and a major obstacle to its development of theindustry is the high fluoride content of Antarctic krill.Fluorine is an essential trace element. It is beneficial for the health of bones andteeth in low concentration but toxic in excess. The fluorine content in Antarctic krill isfar more than the adult safety fluoride intake amount limit, which is not suitable forhuman use. How to remove fluoride is an important subject in the industrialdevelopment of Antarctic krill.In this article, eleven different methods to extract oil with low fluoride level fromAntarctic krill were investigated. The extraction process is the defluoridation process.The methods were all carried out by organic solvents, without destroying anynutrients and introducing any impurities. They can be divided into three kinds:One-step extraction, two-step extraction and three-step extraction. The open typeashing-ion selective electrode fluoride analysis was adopted to measure fluoridecontent. We choose the best method for final process design.The oil of the best method was extracted from krill using three separateextractions. First,100g samples were mixed with acetone. The krill: solvent ratio was1:6(w:v) and the temperature was25℃. The extraction was conducted six times untilthe supernatant basic colorless. It costs about1.5h per time. After extraction, they were divided into krill slag and oil. Second, the residue of first step was extracted by95%alcohol. Third, the oil extracted by the second step was extracted again byacetone and the oil was obtained. The process of the last two step of extraction issimilar to the first step extraction. After extraction,3.23g dark red oil was obtained.The average concentration is3.42ppm and the total amount of fluoride is11.05μg.The oil can be mixed with the oil extracted by acetone, which is the first step of thismethod. The average concentration is13.57ppm,and the amount of oil is9.49g.apparently, this mixed oil has a good defluoridation effect and high extraction rate.The methods were all carried out by organic solvents, which carried out withoutdestroying any nutrients, suggesting this would be an ideal method of defluoridation.All in all, this is a new and efficient method to remove fluoride from Antarctic krill oil.We expect this article could provide a theoretical basis for the development ofpharmaceutical, food industry and so on.