Nutrition Analysis And Fluoride Safety Preliminary Study Of Antarctic Krill Head And Shell

In processing Antarctic krill (Euphausia superba), a good deal of waste, such as heads and shells, will be produced, part of which will be recycled as raw materials producing chitin and chitosan but most of which will be discharged into the sea, leading to not only a serious waste of resources but also a pollution of the marine ecological environment. Such discarded Antarctic krill’s heads and shells are rich in nutriments, such as protein, astacin, unsaturated fatty acids and chitin, and contain various amino acids and essential trace elements in the human body. Therefore, how to develop and explore them scientifically and to improve their recycling values has been an important problem tackling with integrated utilization of Antarctic krill. Abnormal fluorine content in Antarctic krill has become a bottleneck of the development and utilization of Antarctic krill. According to the national standard method, This study, nutrient contents of heads and shells of Antarctic krill obtained in different processing ways will determine and make contrastive analyses, and their fluoride contents will also make contrastive analyses by fluoride-ion selective electrode method so as to explore preliminarily the fluorine safety of Antarctic krill obtained in different processing ways, providing a reference for the integrated utilization of Antarctic krill and their waste such as heads and shells.The nutrition compositions and amino acids, fatty acids, mineral elements, fluorine in dried Antarctic krill head and shrimp shell were compared in this study. The results showed that the crude protein contents of the shrimp head and shell were57.61%,46.98%, ash contents were12.48%,14.26%, crude fat contents were5.16%,5.09%, respectively. Shrimp head and shell were detected18kinds of amino acid, total amino acids were43.07%and47.03%, respectively, in which the content of8kinds of essential amino acid to the human body were18.98%and20.39%, and accounted for44.06%,43.35%of the total amino acids. Besides, there were more flavor amino acids in shrimp head and shrimp shell, and the contents accounted for36.70%and36.08%of the total amino acids. Except that, essential fatty acids in the shrimp head and shrimp shell were rich, more content in oleic acid, linoleic acid, EPA and DHA, and the unsaturated fatty acid content is highand accounted for50.31%and52.87%of total fatty acids. Shrimp head and shrimp shell contain a variety of mineral elements, including calcium, potassium, sodium, magnesium and four kinds of major elements, meanwhile containing iron, copper, zinc, manganese, selenium, essential trace element. The fluorine contents in shrimp head and shrimp shell were1430mg/kg and1930mg/kg, respectively.Antarctic krill and their machined shells were determined, and their water, ash, crude protein and crude fat contents were79.03%and76.06%,2.93%and4.06%,12.34%and14.69%,3.09%and1.82%, respectively; the whole Antarctic krill and their shells contained a full and rich range of amino acids, and their total amino acid contents were10.43%and10.07%, respectively. Antarctic krill’s heads and shells are rich in mineral elements, including four macroelements (potassium, calcium, sodium and magnesium) and five essential trace elements in the human body (iron, copper, zinc, manganese and selenium), and the fluorine content in the whole Antarctic krill and the shell were607.1mg/kg and872.1mg/kg, respectively. The shell of Antarctic krill1.43times as much fluorine content as the whole shrimp, and both of them were higher than muscles,226mg/kg, showing that the fluorine of the Antarctic krill mainly exists in the shell and that an immediate shelling will minimize the transfer of fluoride from shell into the muscle.