High-valued And Comprehensive Utilization Of Waste Liquor Of Processing Sea Cucumber

Waste liquor of processing sea cucumber is produced during cooking sea cucumber to inactivate enzymes, in which the ingredients are almost the same as sea cucumber. The processing liqour is usually discharged directly, which causes environmental pollution as well as waste of resources. If the active ingredients could be extracted from the waste liquor, the sea cucumber processing would be value-added. This work will focus on separation and purification of the active ingredients from the waste liquor, and investigation on the physical and chemical properties and biological activities of these active ingredients. It will provide technological guidance for the comprehensive utilization of waste liquor of processing sea cucumber.Firstly, salting-out extraction system of ethanol/ammonium sulfate was used to separate polysaccharide, melanin and saponin simultaneously from waste liquor of processing sea cucumber. Their structures, physical and chemical properties and biological activities were also studied. Saponins and melanins were enriched in the upper and lower phases of salting-out extraction system of ethanol/ammonium sulfate, respectively. Proteins and polysaccharides were distributed as solid precipitate between the upper and lower phase. Polysaccharide was extracted from the solid dried powder after enzymatic lysis of papain. The metachromatic effect, infrared spectral analysis, and the content of sulfated group indicated that polysaccharide in the waste liquor of processing sea cucumber had not significant difference with that of sea cucumber wall. With acid precipitation and alkali dissolution, melanin could be extracted from the lower phase of aqueous two-phase extraction system. The melanin was insoluble in water, methanol and ethanol, but soluble in dimethyl sulfoxide (DMSO) and0.5mol/L NaOH solution. It has similar structure as other melanins of various species according to their infrared spectra. The crude saponins in the upper phase were prepared by macroporous adsorption resin chromatography. They had significant inhibition on Human promyelocytic leukemia cells (HL-60) and histiocytic lymphoma cells (U937), whose half inhibitory concentration (IC50) were0.088μg/μL and0.172μg/μL respectively. Pressurized silica gel column chromatography can significantly improve the purity of each eluted fraction and be used to obtain saponin be with a high purity.Secondly, the two-liquid-phase system of n-hexane-ethanol or t-butanol-waste liquor was used to separate proteins, polysaccharides and saponins from the waste liquor. Proteins and polysaccharides were distributed in the lower phase as solid form, and saponins and lipids were extracted into the upper phase. The effects of different alcohol//-butanol concentrations and the amount of n-hexane on phase formation and recoveries of proteins, polysaccharides and saponins were explored. No significant variation in the recoveries of proteins and polysaccharides was found, but the recovery of saponins increased with the increase of ethanol concentration and the amount of n-hexane. t-Butanol/n-hexane system was more appropriate to separate proteins, polysaccharides and saponins with yields of93.11%,84.74%and93.57%, respectively. The content of proteins and polysaccharides in the solid were45.53%and20.43%, respectively. After determination of heavy metal ions in the dried solid powder, As and Hg were removed better to meet national testing standards, but Cd and Pb ions needed to improve in the furture.