Studies On The Extraction And Purification Process Of Disodium5’-inosinate From Whole Cell Catalysis

Disodium5’-Inosinate is a kind of nucleotide. Disodium5’-ribonucleotide whichconsists of disodium5’-Inosinate (IMP) and disodium5’-guanylate (GMP) is used as a foodadditive in nucleosides, which can enhance food flavor, in synergy with monosodiumglutamate to provide umami taste. Compared with chemical synthesis, enzymatic synthesis ofIMP from inosine catalyzed by acid phosphatase has the features as follow: the synthesisconditions are mild; the enzyme specificity is high; process is safe and environmentallyfriendly and so on. It was widely focused on by domestic and oversea scientific researchers.In this paper, the technology of modern biochemical separation is used to carry out asystematic research on the extraction and purification process of the reaction solution of5’-inosinic acid which is produced by whole cell catalysis. This paper may be helpful toextraction and purification technology of5’-inosinic acid produced by whole cell catalysis.Effects of pH and temperature on the stability of5’-inosinic acid reaction solution wereinvestigated. The results showed that pH had significant effect on the stability of5’-inosinicacid. The reaction solution was susceptible to degradation in acidity and relatively stable inalkalinity. The reaction solution was also stable in alkalinity when it was at high temperature.Preprocessing and solid-liquid separation of reaction solution were studied to find out theeffects of agglomeration, flocculation, heating-up, pH adjustment and additive to the reactionsolution on the separation. Meanwhile, separations of solids from reaction solution viacentrifuge, ceramic membrane, tube centrifuge and plate and frame filter press were compared.The results showed that the process of heating up, pH adjustment and additivesupplementation followed by plate and frame filter press is feasible to carry out solid-liquidseparation from reaction solution.Gravimetric method was used to measure the solubility of phosphates mixtures,5’-inosinic acid and inosine. At the same time the effects of pH and temperature on thesolubility were also investigated. The nephelometry was used to measure the super-solubilityof phosphates mixtures and5’-inosinic acid. Meanwhile, the effect of the temperature on thesuper-solubility was studied. The changes of solubility, super-solubility and metastable regionunder different pH and temperatures were also studied.Crystallization processes of phosphates mixtures,5’-inosinic acid and inosine fromfiltrate were investigated. The optimum conditions of crystallization processes were obtainedin terms of the industry standard of QB/T4261-2011of food ingredients IMP through thedetection of IMP crystalline Products.