Study On The Rapid Fermentation Technology Of The Low-salinity Pickled Potherb Mustard-DaoDu

Daodu is a pickled vegetables with Zhejiang Characteristics, it is made of leaf mustard and it is popular with people because of its delicious and flavor. At present, the Daodu production use more natural fermentation or high salt production in the form, the shortage is needing a long time. To seek for the effect of various conditions on nitrite content of Daodu, decrease nitrite and short fermentation period, the fermentation factors of Daodu were researched, the key technologies in the quick fermentation of Daodu with low salt were optimized. In order to meet the consumer’s require for nutrition and delicious.The main research results as follows:(1) Six bacterias strains have been separated from Daodu. By antibacterial test and security checks, two of them were gained, which were d-1, d-4.It has special good effect for thedegradation of the nitrite. By the biocemically test, the results showed that d-1 and d-4, were Lactobacillus. plantarum.(2) Based on changes of nitrite contentrations during yeast systematically studied. Single-factor experiments of Daodu in different pickling temperatures, pH, salt concentrations and inoculation amount. Result showed that the optimum temperature was 25℃, optimal salt concentration was 5%, optimal inoculum size was 5%, pH was 4. The nitrite peak appearance was earlier under this condition, nitrite contentrations was lower. Daodu has the best quality in the end.(3) We used three factors and three levels Box-Behnken tests to determine the best technology. Factors of the concent of salt, inoculation amount and pH were selected to investigate the effects on the nitrite content, the grades of sensory and the count of Viable of L. The corresponding regression models were established with the nitrite contentration, the sensory evaluation values and the Viable count of Lactobacillus as the test value. The optimal curing condition were as follows:salt 5.20%, pH4.60, inoculation amount 5.00%. The theoretical contentration of nitrite, the sensory evaluation values and the Viable count of Lactobacillus were 0.64 mg/kg, 84.43 points,311.451g (CFU/ml), respectively. Values obtained from the experiments were 0.67 mg/kg,84.65 points,307.23 lg(CFU/ml), respectively. Therefore, the relative differences between theoretical and experimental values is about 1.50%.(4) Compared with the wild curing, when the salt concentration was 5%, and inoculum size was 5%, the inoculated fermentation time is short, it is from 90d to42d, nitrite content was 1.06 mg/kg.(5) This study intended to develop a Daodu soft canned food products. Factors of DaoDu, comminuted-meat and bean curd cake were selected to investigate the effects on the sensory evaluation values. The corresponding regression models were established with the sensory evaluation values as the test value. The results indicated that better ration of DaoDu:comminuted-meat:bean curd cake was 60:34:29. The theoretical sensory evaluation values was 87.90points. Result of the experiments was 84.65 points.Therefore, the relative various between them is 1.60%. The better sterilization was high pressure sterilization in 121℃, for 30 min after vacuuming package. Not only it taste but also its nutritional value had been improved by this study.