Lub luag haujlwm ntawm cov khoom siv refining yog tshem tawm impurities los ntawm cov roj ua noj
Kev ua haujlwm ntawm cov cuab yeej ua kom zoo yog tshem tawm cov impurities hauv cov roj ua noj, tswj cov roj ntsha lom neeg, thiab khaws cia lossis rho tawm cov khoom muaj txiaj ntsig. Qhov tseeb, qhov chaw kho kom zoo tsis tshem tag nrho cov impurities, tab sis xaiv tshem tawm lawv. Lwm cov khoom ntawm cov roj thiab cov rog uas tsis yog cov roj triester yog hu ua impurities.
Raws li qhov muaj pes tsawg leeg thiab cov khoom ntawm impurities hauv cov roj tag nrho, nws tuaj yeem muab faib ua peb pawg:
(1) insoluble khoom impurities, xws li sediment, pluas mov hmoov, fiber ntau, av nplaum, catalyst thiab lwm yam.
(2) colloidal impurities, xws li dawb fatty acids, sterols, vitamin E, pigments, vitamins, gossypol, thiab lwm yam.
(3) volatile impurities, xws li dej, cawv, hydrocarbon solvents, ntxhiab tsw, thiab lwm yam.
Feem ntau impurities tsis zoo rau qhov zoo thiab cia cov roj. Piv txwv li, dej tsis tsuas yog cuam tshuam cov pob tshab ntawm cov roj, tab sis kuj txhawb cov hydrolysis thiab rancidity ntawm cov roj. Dawb fatty acids cuam tshuam tsw thiab txhawb kev deterioration. Phospholipid tuaj yeem ua rau cov roj cloudy, thiab thaum cua sov yuav ua rau dub precipitate, foaming, iab, thiab lwm yam pigments ncaj qha cuam tshuam cov xim roj, tab sis kuj txhawb roj rancidity; Lub xub ntiag ntawm colloid, sulfur-muaj, phosphorous tebchaw, xab npum taw, hnyav hlau ntsev, thiab lwm yam, ua rau nws nyuaj rau tshem tawm cov kua qaub hauv cov txheej txheem tom ntej xws li stripping.
