| Sea cucumbers contain autolysis enzymes.Most sea cucumbers cannot be long distantly transported or reprocessed unless becoming not enzymatic after water-boiling.In recent years,the rapid development of the sea cucumber industry makes popular more and more sea cucumbers processing liquid.This kind of liquid contains almost the same nutrients as sea cucumber does,and in big capacity.If it is poured away directly,it will not only pollute the environment,but also cause economic loss.Thus,if effective ingredients can be extracted from the liquid,it not only reduces environmental pollution,but also increases additional value of sea cucumber with cost reduction and profit growth.Because of the high amount of protein and polysaccharide in the liquid,being nutritional and soluble,they are easily absorbed in human body.According to it,this paper will discuss the extraction methods of protein and polysaccharide from sea cucumber processing liquid.Firstly,the method of flocculation separates and extracts proteins and polysaccharides from processing liquid.The extraction rates of three kinds of flocculants were investigated and the influence factors were optimized.The results shows that proteins and polysaccharides and flocculants are separated out together in the form of sediment.Then the solid and liquid parts could be completely separated after centrifugation.After optimizing experimental conditions,chitosan has the best extraction effect out of the three flocculants selected.The highest content of extracted protein was 0.496 g/L and the polysaccharide content was 0.398 g/L when chitosan was used as a flocculant by adding into 5% volume of processing liquid and standing for 150 min in 30? and pH3.In addition,the paper investigated the content of heavy metals in the flocculated sediment.The result shows that one third of heavy metals remains in the liquid and two thirds in the sediments after flocculation and precipitation.Secondly,proteins and polysaccharides were separated from flocculated sediments by enzymatic hydrolysis.The separation effects of two methods and four proteases were investigated.The results shows that the method of direct enzymatic hydrolysis has advantages of easy operation,less heavy metal ions in solids and no other by-products.But disadvantages are low rate of less than 45% of enzymatic hydrolysis and poor separation effect of protein and polysaccharide.While the method of alkali hydrolysis followed by enzymatic hydrolysis has high rate of enzymatic hydrolysis,good separation effect of protein and polysaccharide and the hydrolysis rate is as high as 86.17%.But it has high content of salt,high cost,extremely low purity of protein,peptide and amino acid.This method needs further optimizing to reduce salt content and remove more heavy metals without reducing hydrolysis rate.Finally,based on the experimental parameters,we carried out the design of the technology,calculated the volume of equipment and made economical estimation of the whole process of technology.The results show that in terms of constituents,wage,welfare,repair and depreciation are decisive factors of production costs,accounting for 61.34% of the total cost.Sensitivity analysis shows what the most sensitive to changes in production costs are wage and welfare,then repair and depreciation,and finally sales.Therefore,to reduce the total production cost and improve economic efficiency,reducing staff,selecting more automated equipment and reducing the cost of sales can be listed into consideration.The total annual production cost of the whole process is 896.7 million yuan and the net profit is 739.2 million yuan.This shows that the technology has considerable economic benefits. |
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