Study On Calcium Propionate Prepared With Eggshell

Calcium propionate was novel, safe and effective antiseptic-germicide, which demanded a lot in the over the world and has a vast prospect. It can produce a great many of social benefit and economic benefit to study on the calcium propionate prepared with eggshell.The yield and purity of calcium propionate prepared by eggshells is low by the previous methods. The utilization of eggshell calcium propionate is limited wide spreadly because few studies on the physicochemical property, characterization and mildewproof effect of eggshell calcium propionate. In this paper, the eggshell membrane separation efficiency has been improved significantly, and the physical and chemical composition of eggshell and its membrane has not changed. The yield of calcium propionate prepared with eggshell was inproved by second conversion. The physicochemical property, characterization and mildewproof effect of eggshell calcium propionate was studied. The main research results as follows:The eggshell membrane separation efficiency has been improved by 41.04% when get rid of the eggshell powder whose size less than 0.074 mm. The result shows that: when used the yield of eggshell as the indicatrix, the optimum eggshell membrane separation conditions are below:mixing time 20min, liquid ratio of 1:10, mixing speed 600 r/min, the separation times 4, can get the yield of eggshell up to 94.47%, the membrane residual rate is 0.27%, When used the yield of membrane as the indicatrix, the optimum eggshell membrane separation conditions are below:mixing time 10 min, liquid ratio of 1:6, mixing speed 400 r/min, the separation times 4, can get the yield of eggshell membrane up to 4.20%, the membrane residual rate is 3.34%.The optimal reacting conditions as follows:reaction temperature 90℃, the liquid ratio 1:16, the amount of propionate 180%, the reaction time 5 h. Under these conditions, the yield of eggshell calcium propionate was 83.26%. The optimal second conversion as follows:reaction temperature 78.0℃, the liquid ratio 1:17.40, the amount of propionate 159.70%, the first reaction time 1.8 h, the second conversion time 56.0 min. Under these conditions, the yield of eggshell calcium propionate was 98.58%.CMC was best flocculant in the purification of eggshell calcium propionate. The optimal reacting conditions as follows:the mount of flocculant 0.0026%, the purification temperature 89.0℃, the amount of Ca(OH)2 0.96 g, the purification time 21.0 min. Under these conditions, the fineness of calcium propionate was 99.20%.The CaCO3 crystal in the eggshell was encapsulated with protein fiber while the CaCO3 crystal in the commerical-grade CaCO3 was homogeneous by viewing the SEM of eggshell and commerical-grade CaCO3. The eggshell was formed by CaCO3 crystal and MgCO3 crystal though the photogrape of XRD. The physicochemical property of eggshell calcuim propionate is better than calcuim propionate prepared with commerical-grade CaCO3. The eggshell calcuim propionate is in consistent with HG2921—1999. The commercial-grade calcium propionate consisted of irregularly shaped, rough particles, polycrystalline aggregates. Small fragments in sample were adsorbed on the larger crystals. Compare to calcium propionate prepared with commercial-grade CaCO3, the size of crystals in eggshell calcium propionate was relatively homogeneous while large volume crystals were available sparingly. The eggshell calcium propionate and the calcium propionate prepared with commercial-grade CaCO3 consisted of calcium propionate monohydrate and calcium propionate anhydrous though the photogrape of XRD. Form the TG of calcium propionate, The ability of high megatemperature tolerance of eggshell calcium propionate was stronger than calcium propionate prepared with commercial-grade CaCO3.Eggshell calcium propionate puritied was found to be more effective than commercial-grade calcium propionate in preventing fungal bacterial filament including Penicillium and Aspergillus form milden and rot bread regardless of concentration. The MIC of impure eggshell calcium propionate, purificatory eggshell calcium propionate, commercial-grade calcium propionate at pH 6.0 was 0.6mg/mL. Eggshell calcium propionate and commercial-grade calcium propionate did not inhibit the yeast regardless of concentration. When 0.3% calcium propionate was add to bread, the eggshell calcium propionate puritied can ertend more 1-2 days’shelf life of bread stored at 25℃than impure eggshell and comerical-grade calcium propionate.