Study On Recovery Proteins From Surimi Waste Water Based On ISP Via Pressurized Acid Gas

In recent years, due to the change of the fishery processing in total marine captureyear by year, these processing plants become listlessness and the question of industrywaste water treatment is getting more and more serious. Also the protein which hasunderlying value can not get good recycling to application for its purity and qualityreason. For this, volatile acid （mainly used CO₂gas） ISP technology to recovery theproteins in the surimi waste water arised at the historic moment.Firstly, the precipitation mechanisms of isoelectric precipitation in surimiwastewater were researched. Through analysed surimi wastewater composition showedthat its initial protein content was about7⁹mg/ml, initial pH value was about7, fatcontent at0.4%, and isoelectric point distribution between4and6.5, the main proteintypes was water-soluble protein and we have known that the proteins’ isoelectric pointtherein were distributed in two groups,they are in near4.3and6.0, respectively,and theformer was main.With the inorganic acid adjust pH to protein precipitation, the curveform was different from a single isoelectric point form and knew that ionic strengthand acid type ara both influence the sedimentation effect.Secondly, according to the requirements of the pressure and centrifugal condition,the experiment pressure equipment were designed which based on XiangYi TDL-5Mcentrifuge, mainly including the rotor, measuring cans, buffer cans and the workbench.Selection of equipment design standard, thickness accounting and maximum speed fora detailed explanation.Based on this, the volatile acid ISP technology for recovery the proteins in thesurimi wastewater were studied. Used surimi wastewater as the research objectobtained the pressure-pH value curve, it showed that initial pH value, temperatureeffect on the recovery, and when the concentration of surimi wastewater higher than3mg/ml, single CO₂solution was never achieved its isoelectric point, and must usedother methods collaborative reduce acidity, therefore, the method of the entrainmentacid method were put forward to reduce the wastewater pH value. Through the singlefactor experiment found that entrainment acid temperature, entrainment acidconcentration and mixed time are influence the effect of recovery. Then they wereinvestigated based on a three-level, three-factor Box-Behnken design optimized withresponse surface methodology: When acetic acid concentration is100%, and the entrainment temperature was78.19, the reaction time is20min, the final pH is4.58which could reach the main protein isoelectric point.Finally, the characteristics of surimi wastewater protein were focused on, proposedisoelectric grading precipitation method of volatile acid （including entrainment acid）ISP technology to recovery of proteins in surimi wastewater. Through the adjust order,controllable research and recycling protein stability were studied and thought isoelectricgrading precipitation method used in volatile acid ISP technology would be completelyfeasible finally.In short, volatile acid ISP technology as a new protein separation method, it hadmany advantages and good development prospect, the process was discussed withrespect to theory and applications in this paper,it were widely used in many otherisoelectric point protein system, to bring value for the society.