Nutritional Evaluation And Defluorination Of Antarctic Krill

This paper is based on Antarctic krill.The differences between 5 kinds of Antarctic krill products were compared.Due to the high fluorine content in Antarctic krill,in order to explore the existence of fluorine,this paper studied the relationship between the different states of fluorine in different parts of the Antarctic and its basic physical and chemical properties.On the basis of above study,I do the research on the removal of fluoride from Antarctic enzymatic hydrolyzate and Antarctic krill meat.The aim is to provide some theoretical basis for the exploitation and utilization of Antarctic krill.1 The nutritional components of different Antarctic krill products were analyzed and evaluated by national standard methods,and compared with each other.The results showed that shrimp meat was riched in protein,shrimp paste enriched in lipid,dried shrimp and shrimp powder have a large content of trace elements.18 kinds of amino acids were detected in the five samples.The proportion of essential amino acid of the whole shrimp,shrimp meat,shrimp paste and shrimp powder were accorded with the quality standard of FAD/WHO.BCAA/AAA ratio,amino acid score and essential amino acid index were all optimized with shrimp meat.The contents of polyunsaturated fatty acids in the whole shrimp,shrimp paste,shrimp paste,dried shrimp and shrimp meal were 40.84%,47.12%,43.05%,42.59%,39.95%.The content of EPA+DHA in shrimp meat was highest,?-6/?-3 was accorded with the recommended standard.Comprehensive analysis,Shrimp meat had the highest nutritional value and good prospects for development.2 Based on continuous chemical and ultrasonic extraction,the fluorine content and the existing forms of fluorine in Antarctic krill whole shrimp,shrimp head,shrimp meat,shrimp shell are analysed.The result showed that the content of fluorine was arranged in order:shrimp shell > shrimp head > whole shrimp > shrimp meat.The residual fluorine was the highest in different parts,followed by was the exchangeable state,the content of fluorine and organic fluorine was relatively low,and the water soluble fluorine content was very low.Thus it can be seen,most of the fluorine inAntarctic krill was exchangeable fluorine and residual fluorine,water soluble fluorine content which can be absorbed easily by the body was not high.Correlation analysis showed there was a significant positive correlation between water soluble fluorine and exchangeable fluorine(r=0.495**).The fluorine in oxidation state was significantly negatively correlated with residual fluoride(r=-0.254*).Organic fluorine and residual fluorine were positively correlated(r = 0.312*).There was also a significant positive correlation between water soluble fluorine and pH,water soluble fluorine and moisture content(r=0.737**,r=0.292*).Organic fluorine and protein content showed a significant positive correlation(r=0.324*).Residual fluoride and protein content were negatively correlated(r=-0.366*).This study can provide scientific basis for the different forms of fluoride in different parts of Antarctic krill,and it also provide a theoretical basis for the research on the defluorination of Antarctic krill.3 In this study,the rate of defluorinating and amino acid losses removal rate were regarded as the index.The effects of four different calcium sources to Antarctic krill hydrolysate fluoride removal were compared.Adsorption and ion precipitation were combined to remove the fluoride.Based on the single factor experiment,the rate of defluorinating being as the response value,and the study used the response surface optimization method to optimize defluorinating method.The kinds and contents of amino acids in the peptide was detected by automatic amino acid analyzer before and after experiment.The results showed that,calcium lactate was the best calcium sources of removing fluoride.The best removal technological conditions were as follows: mass rate was 1:4,pH was 9.0 and the flow rate was 2.0 mL/min.The removal fluoride reached 93.98%±0.04% under this condition.The kinds of amino acids in the peptide were not changed before and after the removal of fluorine,the total loss rate of the amino acids was only 3.49%.The results indicated that the combined methods have good effect on enzymatic hydrolysate defluorination.4 In this paper,6 kinds of substances such as hydrochloric acid,ammonium chloride,sodium citrate,calcium chloride,sodium chloride and chitosan were used to react with the Antarctic krill.And we make two groups:.supersonic group and ordinary group.The results showed that the fluoride removal rate of the supersonic group was better than that the group which are not supersonic.The defluorination rate of chitosan from supersonic was 35.59%,which was the highest defluorination rate.Most of the water-soluble fluorine and exchangeable fluorine can be removed from the Antarctickrill.The protein content,amino acid content of shrimp meat after ultrasonic treatment of 6 kinds of chemical substances were detected.The results showed that the protein loss rate,total amino acid loss rate,essential amino acid loss rate and amino acid loss rate of shrimp meat which was react with chitosan were low.Chitosan can be used as a good defluoridation substance for Antarctic krill shrimp meat.The results of electronic tongue show that chitosan had little effect on the overall taste profile of Antarctic krill shrimp.The results of electronic nose showed that chitosan had the least impact on the Antarctic krill.