The Development Of Ferment Fish

Aquatic products are famous for the low fat, high protein, nutritious and good taste. FAO calculate that in 2030 person year consumption amount will raise 19-21kg from 16kg and the increment of Chinese Mainland will be 84%. With the increase of consumption, nutrition security and new type aquatic products are needed by the consumer.In this paper, lactic acid bacteria were the main research objects. Four lactic acid bacteria stain were studied for the fermentation strain. Then the optimum salinity,pol and temperature for the fermentation growth and pH were determined through single factor test analysis respectively and the Response Surface Methodology （RSM） which was analyzed by the software Design-Expert. The process of fermented chub was studied by use of the fermentation and the changes of physicochemical between the fermented fish and before also studied. Optimization of the technological parameter will provide reference for the research and development for the new style aquatic products.The research of the subject was carried out from these aspects as follows:1. The selection and identification of fermentationThe fermentation will be selected from four strain stored up at lab by the test of acid production, salt resistance and nitrite resistance. Then investigate decomposition to protein and fat. The fermentation should have strong resistance to salt and nitrite, and no obvious decomposition to protein and fat. Then identify the strain selected by morphology and physicochemical test.2. Optimization of culture condition of Lactobacillus brevis014 for fermented fish by response surface methodologyIn this part, the optimum salinity,pol and temperature for Lactobacillus brevis014 （ Lb014 for short） growth and pH were determined through single factor test analysis respectively and the Response Surface Methodology （RSM） which was analyzed by the software Design-Expert. The multivariate non-linear model was applied to study the interaction and optimization of the growth and pH value parameters for Lb014. The results of the growing curves showed that the optimum culture conditions of Lb014 are : pol 6.55%, salinity 1.07% and temperature 40.58℃.Under the optimum conditions the minimum pH value of Lb014 was 5.1291, and the OD600 was 0.1779. Significant interaction between pol and salinity as well as between salinity and temperature, while the interaction between pol and salinity was not significant. The experimental results indicated that the proposed model is reasonably accurate and can be used to predict and describe the growth and pH value of Lb014 under different conditions.3. Optimization of process parameters to the fermented fishThe process of fermented chub was studied by use of Lactobacillus brevis 014 as fermentation. The optimum salt addition, sugar addition, fermentation addition, temperature and time were defined by the single factors test and the L16（45）orthogonal experiment according to influence the pH of fermentation liquor. The optimum formula was carried out according to the pH and AN to the fermented fish. The experimental results showed that the optimum conditions were as follow: salt 2%, sugar 2%, fermentation 1%(10⁶CFU·mL^-1), fermented time 20h, fermented temperature 42℃. Sensory evaluation under this optimum conditions gain high scores.4. The physicochemical chang between the fermented fish and beforeAfter ferment the moisture and ash content rise; the Aw got lower; the change of fat content was steady; and Pr-N get lower when the non Pr-N rise. The rise of moisture made the muscle organization more flexible; lower Aw will stop the growth of bacterium in a way. The content of nitrite was 2.69mg/kg after ferment which was much lower than the nation standard.