Microbial Fermentation
Kev tsim cov pos hniav xanthan pib nrog microbial fermentation ntawm xanthan. Txoj kev siv ntau lawm yog * Xanthomonas campestris *; los ntawm kev tswj fermentation nyob rau hauv ib tug haum nruab nrab nutrient, carbon cov chaw, nitrogen qhov chaw, thiab minerals yog hloov dua siab tshiab rau hauv xanthan polysaccharide. Thaum lub sijhawm no, kev tswj hwm nruj ntawm qhov kub thiab txias, pH, yaj cov pa oxygen, thiab kev kub ntxhov ceev yuav tsum ua kom muaj zog microbial metabolic kev ua si thiab polysaccharide tawm los. Tom qab ua tiav ntawm fermentation, cov khoom tshwm sim feem ntau yog ib qho emulsion uas muaj cov kab mob hlwb thiab impurities.
Kev sib cais thiab kev huv
Cov pos hniav xanthan nyob rau hauv lub fermentation broth yuav tsum tau zoo los ntawm kev sib cais thiab purification txheej txheem. Cov txheej txheem feem ntau muaj xws li centrifugation, nag lossis daus, lossis membrane filtration. Feem ntau, fermentation broth yog tov nrog isopropyl cawv los yog ethanol kom precipitate xanthan polysaccharide, uas yog ces ntxuav kom tshem tawm cov seem ntsev thiab impurities. Cov txheej txheem no tsis yog tsuas yog txhim kho cov khoom purity tab sis kuj txhim kho cov solubility thiab stability ntawm xanthan gum, nteg lub hauv paus rau nws tom ntej ua rau xanthan gum ntsev.
Ntsev tsim
Lub purified xanthan polysaccharide muaj nyob rau hauv lub xeev acidic thiab yuav tsum tau mus rau ib tug neutralization cov tshuaj tiv thaiv los tsim xanthan pos hniav ntsev. Cov ntsev alkaline uas siv rau lub hom phiaj no suav nrog sodium hydroxide, potassium hydroxide, lossis calcium carbonate; Cov tshuaj no cuam tshuam nrog cov pawg carboxyl hauv cov pos hniav xanthan los tsim cov ntsev carboxylate. Cov kauj ruam no tso cai rau kev hloov pauv ntawm xanthan cov pos hniav pH thiab rheological zog, thaum tib lub sijhawm txhim kho nws cov dej solubility thiab nws ruaj khov tiv thaiv ntsev, acids, thiab hauv paus. Kev xaiv ntawm cov hlau tshwj xeeb ions ncaj qha cuam tshuam cov yam ntxwv ua haujlwm ntawm cov khoom kawg.
Qhuav
Cov kauj ruam kawg suav nrog hloov cov xanthan cov pos hniav ntsev rau hauv cov khoom ruaj khov, qhuav tsim nyog rau kev khaws cia thiab kev thauj mus los. Cov txheej txheem ziab kom qhuav muaj xws li kev ziab kom qhuav, khov kom qhuav, lossis kub- cua kom qhuav. Thaum lub sij hawm ziab, ua tib zoo tswj qhov kub thiab av noo yog qhov tseem ceeb los tiv thaiv polysaccharide degradation los yog clumping. Cov pos hniav qhuav xanthan feem ntau nthuav tawm raws li cov hmoov dawb los yog daj daj daj uas tau yooj yim soluble hauv dej, ua kom yooj yim rau nws daim ntawv thov hauv qab hauv cov khoom noj, tshuaj, tshuaj pleev ib ce, thiab kev lag luam.
