Txias-kev ziab (lyophilization) yog qhov qis-kub lub cev lub cev qhuav dej tshuab txawv ntawm ib txwm muaj siab- kub kom qhuav. Nws cov ntsiab lus tseem ceeb yog ua raws li cov yam ntxwv sublimation ntawm dej. Nyob rau hauv qis- qhov kub thiab qis- qhov chaw nqus tsev, cov dej noo hauv cov txiv hmab txiv ntoo tshiab yog khov rau hauv cov dej khov, uas yog sublimated ncaj qha rau hauv cov pa roj thiab sib cais los ntawm cov txiv hmab txiv ntoo cov ntaub so ntswg yam tsis tau dhau los ntawm cov kua dej, thaum kawg tsim ntxeem tau thiab qhuav khov - cov txiv hmab txiv ntoo qhuav.
Kev ua kom khov ua tiav- txheej txheem ziab yog muab faib ua peb theem tseem ceeb. The first is pre-freezing: fresh fruits are cleaned, sliced and shaped, then quickly frozen at a temperature of -30℃to -50℃to lock the fruit's cell structure and prevent cell damage caused by slow freezing. Qhov thib ob yog lub tshuab nqus tsev sublimation kom qhuav: nyob rau hauv lub tshuab nqus tsev kaw khoom ib puag ncig, cov dej khov hauv cov txiv hmab txiv ntoo absorbs tshav kub thiab sublimates sai, tshem tawm 90% -95% ntawm dej dawb. Qhov thib peb yog kev ziab kom qhuav: ntxiv tshem tawm cov dej seem hauv cov txiv hmab txiv ntoo, txo cov dej kawg ntawm cov khoom kom tsawg dua 5%, uas paub txog kev khaws cov txiv hmab txiv ntoo mus ntev.
Piv nrog rau cov tsoos siab -kub ziab tshuab xws li cua kub kom qhuav thiab ci, khov- ziab muaj qhov zoo tsis tuaj yeem hloov tau. Ua ntej, zoo heev cov khoom noj khaws cia. High- kub kom qhuav yuav ua kom sov- cov khoom noj muaj txiaj ntsig zoo xws li vitamin C, fiber ntau thiab cov enzymes hauv cov txiv hmab txiv ntoo, thaum qis -kub khov- ziab yuav luag khaws 98% ntawm cov khoom qub qub ntawm cov txiv hmab txiv ntoo tshiab. Thib ob, thawj saj thiab zoo li kev kho dua tshiab. Qhov qis- qhov kub ntawm lub tshuab nqus tsev tsis ua rau cov qauv ntawm cov txiv hmab txiv ntoo, yog li khov- cov txiv hmab txiv ntoo qhuav khaws cov xim qub, zoo li qub thiab tsw ntawm cov txiv hmab txiv ntoo tshiab, nrog rau cov nkig thiab ntxeem tau zoo nkauj, thiab tuaj yeem rov qab sai sai kom rov qab los ntawm lub xeev ntawm cov txiv hmab txiv ntoo tshiab tom qab nqus dej. Thib peb, ultra{14}}ntev lub neej ntev. Tom qab khov- kom qhuav, 95% -99% ntawm cov dej raug tshem tawm, uas cuam tshuam rau kev tsim cov kab mob, pwm thiab kab mob. Tsis tas yuav ntxiv cov tshuaj tua kab mob, lub txee lub neej tuaj yeem ncav cuag 12-24 lub hlis ntawm chav tsev kub.
Hauv kev tsim khoom, qhov zoo ntawm khov- txiv hmab txiv ntoo qhuav yog cuam tshuam los ntawm peb yam tseem ceeb. Ua ntej, eutectic point ntawm txiv hmab txiv ntoo. Cov txiv hmab txiv ntoo sib txawv muaj cov suab thaj thiab cov dej noo sib txawv, ua rau cov ntsiab lus sib txawv eutectic, uas txiav txim siab qhov zoo tshaj plaws khov kub thiab sublimation voj voog. Qhov thib ob, lub tshuab nqus tsev℃tswj. Lub tshuab nqus tsev ruaj khov yog tus yuam sij los xyuas kom meej cov sublimation zoo ib yam thiab tsis txhob ziab tsis sib xws thiab cov khoom lag luam tsis zoo. Thib peb, ua ntej - tus nqi khov. Kev khov sai sai tuaj yeem tsim cov dej khov zoo hauv cov txiv hmab txiv ntoo, ua kom tiav cov qauv ntawm tes thiab tsis txhob xoob thiab shrunken cov khoom zoo nkauj.
Ua tsaug rau cov txiaj ntsig zoo saum toj no, khov- tshuab ziab khaub ncaws tau dhau los ua lub ntsiab lus siab -kawg ua tshuab rau txiv hmab txiv ntoo thiab zaub. Nws daws cov teeb meem kev lag luam ntawm cov txiv hmab txiv ntoo tshiab lub neej luv luv, nyuaj ntev - kev thauj mus los deb thiab cov khoom noj tsis zoo ntawm cov txiv hmab txiv ntoo qhuav, thiab tau lees paub dav hauv qib siab - cov khoom noj txom ncauj kawg, cov khoom noj me nyuam mos, cov khoom siv thiab cov khoom lag luam xa tawm.
