| Antarctic krill has huge potential of development and utilization because of thegreat biomass and rich nutritional value. Antarctic krill meal is the main form ofprocessing Antarctic krill. With the continuously increasing scale of aquaculture, fishmeal production is declining year by year. Antarctic krill meal is seen as the highquality protein source that can replace fish meal in the aquatic feedstuff industry. So theanalysis and evaluation of the nutrition composition, storage and security of theAntarctic krill meal have practical significance.The study analyzed the general nutritional composition, amino acid composition,pepsin digestibility and fatty acid composition of the Antarctic krill meal, and comparedthe results with imported fish meal, studied the impact of temperature on the Antarctickrill meal storage by analyzing the changes of the quality indexes such as sensory, color,acid value and pepsin digestibility, On this basis, discussed the effect of preservation ofdeoxidizer for Antarctic krill meal, determined the fluorine content of small intestine,blood, liver, kidney and the femur, and analyzed the fluoride deposition in varioustissues and organs and the effects on weight gain. The following results were obtained:1. the contents of crude protein of Antarctic kill meal processed by the Kai LiVessel of Shanghai Deepsea Fisheries Co.,Ltd., Antarctic kill meal processed by the AnXing Seagoing Vessel of Liaoning Deepsea Fisheries Co.,Ltd. and fish meal were62.89%,51.64%and59.98%, respectively. The crude protein contents of the two kindsof Krill meal achieved the first class products index and the second class products index,respectively. The crude fat contents of the two kinds of Krill meal were6.55%and7.81%,and both reached the super products indicators of fish meal national standard.The fat content of the fish meal was higher than that of the two kinds of Krill meal. Thedifference of the crude protein and crude fat between two Antarctic krill meal may be caused by different ship equipment and processing parameters.18kinds of amino acidcontents of the three kinds of samples accounted for66.36%,57.19%and66.36%,respectively. The three kinds of samples were all rich in delicious amino acids,24.65%、25.25%and20.69%, respectively. The essential amino acids index (EAAI) was57.83,57.07,49.89, respectively.∑EAA/∑AA was47.37%,38.01%and38.11%. The aminoacid composition was in line with the ideal model recommend by FAO/WHO. Thecontents of polyunsaturated fatty acids were high in the fatty acids of the three kinds ofsamples. The proportions were43.28%、46.58%、40.25%, respectively. The proportionsof EPA+DHA (36.14%) of kill meal made in Shanghai company were higher than thoseof kill meal made in Dalian company(31.30%) and fish meal(27.65%). The values ofpepsin digestibility were (94.53±0.86)%,(92.37±1.02)%and (93.89±0.56)%,whichwere all in the range of premium products of the fish meal national standard.2. At25℃,30℃and35℃, three kinds of storage temperature, the higher thestorage temperature was, the faster each quality index of the Antarctic krill meal fell. Itillustrated that decreasing the temperature can improve the storage of the Antarctic krillmeal. Three kinds of samples failed to meet the end of shelf life after165d. The sensoryscores were0.92,1.01and1.21, respectively. Acid value was2.03mg/g,2.19mg/g and2.29mg/g. Pepsin digestibility was92.58%,92.09%and91.51%, which were in thescope of fish meal national standards for premium products. TBARS value had not beenmore than20mg/kg and in fresh fish meal acceptable range. In the temperature range ofthe experiment, the Antarctic krill meal still had good quality after165d. It showed thatthe Antarctic krill meal which was produced on the ship had good storage properties.3. Compared with the Antarctic krill meal not adding deoxidizer, sensory score ofthe Antarctic krill meal adding deoxidizer can be increased from1.21to0.93, the acidvalue was decreased from2.29mg/kg to2.00mg/kg at35℃after165d.In the processof storage, adding deoxidizer can slow down the speed of krill meal color changes,TBARS value of adding deoxidizer group were lower than that of not adding group atthe same determination point. But during the storage time the study involved, theinfluence of adding deoxidizer on pepsin digestibility was not obvious. Comprehensivedetermination results of each quality index, adding deoxidizer can effectively inhibit oilrancidity, slow down the speed of color change and obviously improve the quality of the Antarctic krill meal storage. The study showed that adding deoxidizer can serve as asimple and effective method for preserving the Antarctic krill meal.4. The Sodium fluoride solution and the Antarctic krill meal mixed suspension, inwhich the fluorine content were both300mg/L,was give to the Kunming mice bygavage. After seven days, fluorine contents in small intestine of the two groups were(0.19±0.04)mg/kg and (0.18±0.05)mg/kg. Fluorine contents in the blood were(0.76±0.09)mg/kg and (0.50±0.04)mg/kg. Fluorine contents in the liver were(0.80±0.07)mg/kg and (0.42±0.09)mg/kg, the fluorine contents in the kidney were(0.67±0.06)mg/kg and (0.51±0.14)mg/kg. The fluorine contents in the femur were(4603.96±834.77)mg/kg and (3357.06±427.15)mg/kg. Fluorine contents in smallintestine, blood, liver, kidney and femur of the blank group were (0.18±0.07)mg/kg,(0.45±0.03)mg/kg,(0.45±0.08)mg/kg,(0.32±0.06)mg/kg,(484.92±60.42)mg/kg. Itshowed that fluoride in Antarctic krill meal is different from the pure chemistry fluorinein sodium fluoride. The fluoride had no obvious accumulation effect in the smallintestine, blood, liver and kidney, but the fluoride in femoral had significant deposits.The weight gain rate of mice in sodium fluoride group was3.22%.The weight gain rateof mice in Antarctic Krill meal group was7.81%. The weight gain rates of the twogroups were significantly lower than that of the blank group which was12.87%.Theresults of the study showed that fluoride in Antarctic krill powder inhibit the growth ofmice, but the specific metabolism and transformation process of fluoride in Antarctickrill meal remains to be further research. |
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