Process Of A Fish Sauce Made From The Abalone Viscera With Low Salt Concentration By Fermentation Traditional

Abalone(Haliotis discus) is a kind of pseudosciaena, which belongs to Haliotidaes. It is akind of seafood treasures in our country and chiefly produced in Fujian. Abalone visceral whichhas a high quality of protein was usually discarded as waste during the processing of abalone′sand not fully used. In the study, to improve utilization rate of abalone visceral and its incrementvalue, the abalone visceral was used to develop a fish sauce with low salt concentration and richnutrition. We did principium study of the endogenous enzymes, autohydrolysis, judgement of theend in traditional fermentation, electrodialysis desalination. The major achievements and resultswere concluded as follows:1. The endogenous enzymes have been characterized by biochemical and electrophoretictechniques. The effects of pH, temperatures and specific protease inhibitors on endogenousenzymes were investigated. The results revealed that there existed proteases with optimumactivities at pH3-4and pH7-8. And thermal stability assay revealed that proteases at pH8andpH3-4were more stable than proteases at pH7.5. The optimum pH3-4protease with inhibitedby Pepstain was confirmed to be a pepsin-like. The optimum pH7-8proteases with inhibitedby PMSF, SBTI and TPCK were confirmed to be a trypsin-like proteinase and achymotrypsin-like proteinase.2. The technology of autohydrolysis was investigated about abalone visceral andmathematical model was established for autohydrolysis of abalone visceral. Results of singlefactor experiments suggested that optimum conditions were as follows,120s chopping time,22.58kV/cm electric field,8%salt concentration and7h hydrolysis time. The results of theresponse surface experiment showed that the process of autohydrolysis of abalone visceral couldbe predicated well and truly by the mathematical model. The best conditions of autohydrolysiswere as follows,59℃temperature,0.25substrate concentration,3.89initial pH and12.6minultra violet ray time. The result of verification test demonstrated that the content of α-aminonitrogen in autohydrolysis supernatant attained to0.3961g/100ml. The predicted value ofequation was0.3977g/100ml and the good coherence lied in between them．Results ofautohydrolysis of abalone visceral could be predicted well and truly by the mathematical model．3. With the prolongation of fermentation time, sensory evaluation was increased and themaximum value was the ninth month sample. The content of total nitrogen, α-amino nitrogen, specific gravity and red index were significantly increased. The content of TVB-N was firstlyincreased and then decreased. The content of acidity was firstly increased, then decreased andincreased again while the content of salt concentration was totally the same.4. According to the method of fuzzy comprehensive evaluation, the end of traditionalfermentation was studied. It showed that the weights of indexes of fish sauce were respectivelysensory evaluation0.337, total nitrogen0.179, α-amino nitrogen0.104, TVB-N0.051, specificgravity0.137, salt concentration0.067, acidity0.061, red index0.064. The maximumaccumulations of the weighing fuzzy degree were the ninth sample and the tenth sample whichrevealed that the best quality of fish sauces were the ninth sample and the tenth sample.Considering the cost and so on, the best fish sauce was produced with9months in traditionalfermentation.5. The effects of salt concentration of fish sauce and flow velocity on limited currentdensity in electrodialysis were investigated. The mathematical model of limited current densityin electrodialysis was established. It showed that high salt concentration and high flow velocitywere good for the limited current density. The mathematical model for limited current density ofthe electrodialysis apparatus employed in our experiment was ilim=0.0907v0.776c0.9449.6. The effects of voltage, flow rate and salt concentration of fish sauce on salt removalefficiency and amino acid recovery were investigated. Single factor trial of electrodialysisshowed that the optimum conditions for desalination was20V operating voltage,40L/h operatingflow rate and5.14%salt concentration. Orthogonal intersection experiments revealed that20Voperating voltage，60L/h flow rate and5.14%salt concentration were the best condition for saltremoval efficiency and amino acid recovery. Under the best condition, more than80.72%salt inthe fish sauce of abalone visceral was removed and91.66%of amino acid was retained.