The Way Of Improving The Protein Utilization Ratio Of Soy Sauce Residue

Soy sauce residue is the by-product of the soy sauce fermentation, containing rich protein,however, it is often used as feed, fertilizer, causing a great waste. The main content and the resultsare as follows:1. Soy sauce residue by high-salt liquid-state fermentation were treated by the process ofmechanical disruption, adding neutral Protease, adding cellulase treatment to get theinformation of crude protein dissolution rate. Furthermore, the morphology of the skin andthe cotyledons of the soybean slag were examined by scanning electron microscopy (SEM)and the amino acids increase rate were measured by Automatic Analysis Apparatus(AAA).Results showed that the total crude protein of the soy sauce residue was18.54%, and thecrude protein dissolution rate of the soy sauce residue progressed by the above treatment was5.99%,9.88%,12.77%, respectively. The white-floc level in the skin of the soy sauce treatedby the process of adding neutral protease, adding cellulose sharply abated, while thewhite-floc level in the cotyledons changed little. The Ser, Val, His, Thr and Lys increasedrapidly both in the skin and the cotyledons of the soybean slag by comparing the amino acidscomposition before and after cellulose treatment.2. Soy sauce in the high salt diluted state fermentation were treated by the process of addingneutral protease, adding cellulase treatment, respectively, and the indicators of color rate,color matters content, red index, yellow index, amino acids, total sugar, reducing sugar,soluble protein were determined for27days, and the dynamic change regulation of the8index were traced. The results showed that: The change of the reducing sugar of the threegroup of soybean sauce rose at first, then reduced and increased at last. The reducing sugarcontent of group C was more0.03%than group A after27days. The dynamic changes of thesoluble protein content were complexed. The soluble protein content of group B and C weremore0.23%，0.46%than A, respectively. The amino nitrogen change was roughly same withthe total acid. The total acid of group B and C were less0.36%,0.18%than group A,respectively. The amino nitroge content of group B and C were less0.03%,0.06%than groupA, respectively. The change of the color rate, dark color matter, red index, yellow index ofthe3groups increased dramatically with the time. In the27th day, the color rate of the3groups nearly the same. The dark matter content of group B and C were more4.31%,4.70%than group A, respectively. The red index, yellow index of group B and C were higher thangroup A. The red index of group B and C were higher0.77%,0.57%than group A, respectively. The yellow index of group B and C were higher0.73%,0.62%than group A,respectively.