Study On Preparation Of Powder Seasoning From Tilapia By-products

This paper focuses on preparation of powder seasoning from tilapia by-products,then the antioxidation and the physical-chemical properties of the product wereanalyzed. The processing concludes the following four parts: Enzymatic hydrolysis,Bitter and Fishiness removal, Maillard reaction and Drying process.Using thesemethods can cost less than traditional method for the production of seasoning,providing enterprises a reference to produce power seasoning and has importantsignificance in fish by-produces processing and high value utilization.The main tasks and conclusions of this paper are as follows:1. Optimization of Tilapia by-products enzymatic hydrolysis conditionIn order to determine the optimum hydrolysis process, First, the single factor testwas applied to determine the optimal condition of the single enzyme reaction anddetermine the best two enzyme for the next experiment. Then using PB experiment,Steepest ascent test, Central composite test to design the response surface, which canbuild hydrolysis model to predict the degree of hydrolysis. Regression equation:f（x）＝18.0860－2.70951x₂－0.214335x₃－0.208625x₂²－1.20862x₃²＋0.3950x₂x₃（x₂：solid-to-liquid ratio，x₃：time）. From the regression equation, The resultshows that the optimized hydrolysis conditions for the tilapia wastes hydrolysis issolid-to-liquid ratio at1:6.25, temperature for hydrolysis at45℃，hydrolysis time at4hour, pH value at natural value, the enzyme amounts at0.3%, the rate offlavourzyme-papain is1:3. Under this condition, the predicted hydrolysis degree is21.50%, and the experimental value is22.38%. The hydrolyzate contains all kinds ofnecessary free amino acids, which is nutritious, and the amino nitrogen content of upto4.52g/L, suitable for flavor condiment material.2. Research on removal of bitterness and fishiness of enzymatic hydrolysisThree common way of removing bitterness and fishiness of the tilapia waste enzymatic hydrolyzate are microbial fermentation, activated carbon adsorption,β-cyclodextrin, Research on microbial fementation, activated carbon adsorption andβ-CD to find the best way to remove bitter and fishiness from hydrolysates of tilapiawastes. The results shows the best microorganism fermentation conditions, the bestactive carbon adsorption conditions, the best β-cyclodextrin condition, then by thecontent of volatile flavor compounds and amino acid analysis, comparing with thecontent of nutrition changes, finally this research shows microbial fermentation is thebest processing mode to remove bitter and fishiness from hydrolysates of tilapiawastes. The optimized condition for microbial fermentation is:Lc:Lp at1:1, theamount of the germ is2%, fermentation time is16h, and the best temperature is37℃.In this fermentation condition, the hydrolyzate is off bitterness and fishiness,and the liquid is transparent, slightly yellow.3. Research on Maillard reaction processing conditions of adding flavorThe optimal condition for Maillard reaction was established with single factorexperiment and orthogonal test. The results shows the best condition for Maillardreaction is the ratio of xylose: glucose is1:3, reaction time40min,1.0%total sugar（mass ratio）, reaction temperature110°C,0.2%of thiamine,0.2%L–cysteine.Theliquid is light brown which is rich in seafood flavor and pleasant smell, with nobitterness and fishiness. Finally, the antioxidant activity of Maillard reaction producttests showed that MRPS has strong ability to remove superoxide anion radical.4. Optimization of drying process conditionThe product was dried by two different drying methods, spray drying andvacuum freeze drying.Considering physical and chemical properties of the product,the method of spray drying was selected. The optimization of the production processparameters as follows:5%（m/v）Maltodextrin as the carrier,105℃-110℃inlettemperature,80℃outlet temperature. Through the above process, the seafoodflavoring condiment is rich in nutrients and with good sensory properties.