Study On Preparation Of Degradation Products By Combined Treatments Of Bacteria And Enzyme From Sea Cucumber Body Wall And Its Nutritional Support Effect On Hepatoma Chemotherapy Mice

Sea cucumber is a kind of deep-sea echinoderm with high nutritional and medicinal value.It is a good raw material for developing functional food and new medicine.In recent years,with the deepening of the research on the nutrient composition and active substances of sea cucumber,sea cucumber has become a hot research topic in food,medicine and other industries.However,the development of sea cucumber industry is severely restricted by low processing technology,low development degree,single form of deep-processed products and prominent fishy odor.Under this background,the study used sea cucumber body wall as raw material to explore the effects of bacteria and enzyme treatment on the degradation effect and the flavor characteristics of the degradation products.Furthermore,animal models were established to evaluate the activity of the degradation products in vivo.The main research contents and results are as follows:Firstly,the body wall of sea cucumber was used as the main material for enzymolysis and fermentation,and the most suitable bacteria and enzyme were selected under their respective conditions.Then,the effects of different bacteria and enzyme combined treatment on body wall degradation and product flavor characteristics of sea cucumber were investigated.Through the determination of amino acid composition,polypeptide relative molecular weight distribution and other physicochemical indexes in the degradation solution,combined with gas chromatography-ion migration spectrometry(GC-IMS)and electronic tongue analysis of the volatile and non-volatile flavor components of SCDP under different treatment methods,the best bacteria-enzyme combined treatment method was selected.The results showed that the contents of peptides with relative molecular weight greater than 1000 Da decreased and those with relative molecular weight less than 500 Da increased after the combined treatment with bacterial and enzyme.The average value of total free amino acids and total flavor nucleotides increased 1.3 times and 4.1 times respectively under the combined treatment compared with that under the single treatment.The number of volatile compounds in the SCDP increased from 43 in the untreated treatment to 67 in the combined treatment.The results showed that the flavor components of sea cucumber body wall became more complex after combined treatments of bacteria and enzyme.Combined treatments could reduce the content of small molecule aldehydes,unsaturated aldehydes and increase the content of pleasure components such as esters.Based on the nutritional composition of SCDP,according to the preparation requirements and quality indexes of total nutritional formula food for special medical purposes,SCDP was used as the protein source of special medical food to partially replace the protein in nutritional support for hepatoma chemotherapy mice.The nutritional support effect of SCDP in vivo was evaluated by analyzing the changes of nutritional indexes,immunological indexes,Liver function indexes and other related indexes before and after nutritional intervention.The results showed that nutritional support treatment of SCDP reduced the weight loss and prolonged the survival time of hepatoma mice during chemotherapy,and the survival state of mice was improved.At the same time,after nutritional intervention,the serum levels of TNF-αinflammatory factors in mice were significantly decreased,the levels of TP,Alb,Ig G,CD4~+/CD8~+were significantly increased,the liver protein reserve was increased,the liver injury was alleviated,and the nutritional metabolism of mice was improved.In summary,this paper took the body wall of sea cucumber as the research object,designed a method of collaborative degradation of sea cucumber body wall by bacterial enzymes combining the advantages of enzymolysis and fermentation,and obtained SCDP with good flavor and mostly short peptides.The nutritional support effect of SCDP in vivo was confirmed by establishing a mouse model of hepatocellular carcinoma loaded chemotherapy.The results of this paper provide a theoretical basis for the development and utilization of SCDP functional products and are expected to promote the development of high quality and high value utilization of Marine living resources.