| The fishery for Antarctic krill (Euphausia superba) has been highlighted thelargest by tonnage in the Southern Ocean. Antarctic krill has a great developmentpotential as a new abundant resource that can be widely utilized. Lipids content inAntarctic krill was determined to range from12-50%(dry basis) withphosphatidylcholine (PC) as a main ingredient at a high percentage of20-33%.Therefore, Antarctic krill oil is a perfect resource to provide natural PC. The objectiveof the experiment is to develop a method of extraction and separation high-purity PCfrom Antarctic krill oil, which can help to make full use of this abundant resource. PCis a useful bioactive component, which has been extensively applied as naturalemulsification, stabilization and wetting agent in the fields of dietetics, cosmetics,pharmaceuticals, etc. Due to its wide application, enormous commercial and industrialvalues, high-purity PC sees a rapidly increasing demand.In this article, PC was extracted by common laboratory organic solventsrespectively from Antarctic krill oil. Through integrated extracting effect and organicsolvent properties into account, ethanol and acetone was chosen as extraction solventrespectively for the further study. Ethanol extracts and acetone extracts wereseparated very well on silica GF254plate making the further column chromatographypurification easier. Besides, two methods was designed for the extraction, separationand analysis of PC in Antarctic krill oil.Part1: The extraction of PC in Antarctic krill oil by ethanol was investigated andthe PC was separated and purified by using Al2O3column chromatography with95%ethanol as eluent in this paper. Whole process only used ethanol as solventthat ensures the safety of all product samples.Extraction process was studied through single factor test and orthogonalexperiment, and the optimization conditions were listed as follows:1:7(oil-ethanolratio,W/V),30min (extraction time) and25°C (extraction temperature). After six times extraction, extraction efficiency of ethanol extracts was about57.33%±2.48%and the purity of PC was24.73%±0.31%in HPTLC. After the HPTLC quantificationof ethanol-soluble PC in ethanol extracts，total content in Antarctic krill oil was0.125g±0.003g. This method is simple and economical with good repetition andstability. The purified ethanol sample separated by Al2O3column chromatographywas quantified by HPLC. The purity of the purified ethanol sample can reach79.83%±2.44%.Part2: The extraction of PC in Antarctic krill oil by acetone was investigated inthis paper. Then, the PC was separated and purified by using silica gel columnchromatography with chloroform and methanol mixed in different proportions aseluent and exact identification of the purified sample was carried out.The best effect of acetone-extraction was achieved under the conditions of1:11(oil-ethanol ratio,W/V),50min (extraction time) and20°C (extraction temperature)through single factor test and orthogonal experiment. After six times extraction,extraction efficiency of acetone extracts was about48.17%±2.29%and the purity ofPC was22.78%±0.35%in HPTLC. After the HPTLC quantification, total content ofacetone-soluble PC in Antarctic krill oil was0.0705g±0.0016g. The purifiedethanol sample separated by silica gel column chromatography was quantified byHPLC. The purity of the purified acetone sample can reach97.77%±0.66%.IR and GC-MS were used to analysis the acetone-soluble Antarctic krill PC. IRspectras suggested that the acetone-soluble Antarctic krill PC had the samefundamental chemical structure as the standard PC except for some differences in thefatty acid compositions. The purified sample mainly contained five fatty acids,including palmitic acid, oleic acid,7-hexadecenoic acid, EPA, and DHA. Theircontents were41.25%,8.26%,4.60%,31.34%, and14.52%, respectively. The contentof unsaturated fatty acids, including oleic acid,7-hexadecenoic acid, EPA and DHA,was as high as58.75%in the purified sample and the content of EPA and DHA was45.86%. Based on the benefits of being high in PUFAs, Antarctic krill PC may be akind of new source to meet the demand for fatty acids.In this experiment, PC was successfully separated and purified from a new source, Antarctic krill oil. All of these studies provided two systems to preparepurified PC from Antarctic krill. Therefore, a reference basis for the preparation ofstandard Antarctic krill PC was provided by means of these studies. The fatty acidanalysis of the purified PC was also helpful for the evaluation of its nutritional value. |
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