Industrial Cultivation Technique And High Value Utilization Of Abalone And Sea Cucumber

Abalone and sea cucumber have high nutritional value,medicinal value and economic value.However,there sill have many problems in the current industrial technique for sea cucumber and abalone cultivation in our country.Moreover,only the abdominalleg of abalone and body wall of sea cucumber are used in the product processing,resulting in the low utilization efficiency.Therefore,this paper analyzing the best conditions for sea cucumber and abalone growth,then the polyculture of sea cucumber and abalone was also investigated,which could provide the foundation for aquaculture.The abalone shell and sea cucumber's body wall were further used as feedstock for producing calcium fortifier,collagen and collagen peptide,respectively.Firstly,the effects of water salinity and temperature on the abalone/sea cucumber growth were investigated,then the changes of water quality factors and abalone/sea cucumber growth were further evaluated under the polyculture of sea cucumber and abalone.By comparing the survival rate and average daily growing rate,the suitable salinity for both abalone and sea cucumber growth were found to be in the range of 28‰ to 30‰,while the suitable temperature were found to be in the range of 18? to 20? and 16? to 20?,respectively,for abalone and sea cucumber.Moreover,compared with individual culture,abalone-sea cucumber polyculture had no significant effect on water quality factors,but led to a higher growth rate,indicating that polyculture could help to improve aquaculture efficiency.The processing conditions of extracting soluble calcium from abalone shell were optimized by using hydrochloric acid as extraction agent,then the preparation process of calcium fortifier made from soluble calcium were further investigated.The results show that the optimized extraction conditions were as follows:hydrochloric acid concentration 3.48 mol/L,liquid-solid ratio 4.13:1,and extraction time 48.45 min.Under these conditions,the extraction rate of soluble calcium reached a highest value of 94.32%.Moreover,HZ816 resin was used to enrich and recover blue-green pigment from extracted soluble calcium by using 70%ethanol as eluent.After freeze drying,the colourity of blue-green pigment powder E1cm1%(624nm)=112.32.Furthermore,the soluble calcium solution without pigment content was used as a feedstock for producing calcium fortifier.The results show that the best conditions were as follows:citric acid-malic acid-calcium ratio 2:5:8,pH value 7.0,reaction temperature 50?,and reaction time 40 min.Under these conditions,the complexation rate and calcium content of calcium citrate-malate compound were 91.36%and 23.36%,respectively.The processing conditions of extracting collagen and collagen peptide from body wall of the sea cucumber were optimized,and their functional properties were also evaluated.The results show that the best extraction yield of acid-soluble collagen,pepsin-solubilized collagen and water-soluble collagen were 49.35%,43.93%and 34%,respectively.Acid extraction method led to a highest extraction yield,while the highest extraction purity of collagen was obtained with enzymatic hydrolytic method.Moreover,the best conditions for preparing collagen peptide were as follows:papain concentration 2%,material-water ratio 1:20,and extraction time 4 h.Under these conditions,the extraction efficiency and hydrolysis degree of collagen peptide were 74.14%and 14.01%,respectively.The results of SDS-PAGE analysis indicated that the structural feature of collagen extracted from sea cucumber was mainly I type collagen.From the perspective of functional properties,both extracted collagen and collagen peptide showed a good ability of moisture absorption,moisture retention,oil absorption,foamability and foam stability,emulsifying capacity and emulsion stability.