Study On The Key Technology And Process Of Preparing Fish Meal From Aquatic Waste By Solid State Fermentation

With the rapid development of aquaculture and fishing,the demand for aquatic feed protein is increasing.High quality fish meal can promote fish,shrimp and other aquatic animals to absorb and utilize high nutrient,and then promote the growth and reproduction of fish and shrimp.At the same time,a large amount of waste produced in the process of aquatic products is processed extensively as feedstuff,which not only wastes resources,but also pollutes the environment.Using these wastes as raw materials for fish meal production not only saves resources,but also helps environmental protection.Therefore,in this paper,the formula and proportion of fermentation bacteria were studied by using the raw material of aquatic waste material,Bacillus subtilis,saccharomycetes,Lactobacillus plantarum and Lactobacillus acidophilus as fermentation strains,and the total nitrogen content in fermentation products as evaluation index.Screening and optimization of fermentation medium,selection and optimization of fermentation conditions,Experiments were carried out under the optimized fermentation conditions,and the main components of fermented fish meal were determined after the final fermentation product was freeze-dried in vacuum.This study had fully excavated the resource value of aquatic offal material,the process technology was green and safe,which provided some technical support for the development of high quality fish meal and had a good application prospect.The main work and results of this paper are as follows:(1)Four strains of Bacillus subtilis,Saccharomyces cerevisiae,Lactobacillus plantarum and Lactobacillus acidophilus were screened,using Fishery offal as raw material,the content of total nitrogen in fermentation products was the evaluation index.The effects of single bacteria fermentation and multi bacteria mixed fermentation on the production of fish meal were studied.It is concluded that the strain ABCD(Bacillus subtilis+saccharomycetes+Lactobacillus plantarum+Lactobacillus acidophilus)had the best fermentation effect,and the total nitrogen content in the fermentation product was 3846.36±20.52 mgN/100 g,which was much higher than that of single strain and other strains.And in the experiment of the optimumcombination of strains,the ratio of Bacillus subtilis:saccharomycetes:Lactobacillus plantarum:Lactobacillus acidophilus 1:1:1:1 was the best.(2)The effects of wheat bran,ammonium nitrate and urea addition on the content of total nitrogen in fermentation products were studied in the following order:urea addition > ammonium nitrate > wheat bran.And the optimized fermentation medium was aquatic waste material 50 g,adjuncts(starch: molasses: vegetable protein powder 1:1:1)5 %,wheat bran added 15 %,ammonium nitrate added 5 %,urea added7 %,under the optimum conditions,the total nitrogen content in the fermentation product was 5435.75 ±43.97 mgN/100 g.(3)In the optimization experiment of solid-state fermentation process,the final optimization parameters were: excipient addition 2.5 %,inoculum 7 %,fermentation time 96 h,fermentation temperature 30 ?,aerobic fermentation all the time.Under the fermentation conditions,the total nitrogen content in the fermentation products reached 5662.67±50.45 mgN/100 g.After fermentation experiments under optimal fermentation conditions and vacuum freeze-drying of fermented products,the content of protein in fermented fishmeal was 63.28 %,which reached the first grade standard,the crude fat content was 8.56 %,which reached the special grade standard,the ash content was 6.58 %,which reached the special grade standard;and the water content was 5.32 %,according to the fish meal standard.