Ukomisa ngokukghadzisa kuyithekniki yendlela ephezulu yokubulunga ukudla. Ngesikhathi sendlela yokwenza lena, ukudla okukghadzisiweko kuyonyiswa ngaphasi kwegandeleleko eliphezulu ukubulunga izakhamzimba nomnambitheko. Indlela lena isetjenziswa yi-USA’s National Aeronautics and Space Administration (NASA) ukulungiselela ukudla kwabosomkhathi kodwana kuyatholakala koke eentolo ezikulu ezithengisa ukudla.
Ukudla okonyiswe ngokukghadziswa kungenziwa kuthambe godu ngokufakwa amanzi.
Ukomisa ngokukghadzisa kwasungulwa ngu-Jacques-Arsene d’Arsonval e-Paris ngo-1906 bese kwathi muva kwasetjenziswa ngesikhathi sepi yesibili yephasi i-World War II ukubulunga i-serum yeengazi. Ngabo 1950s i-indastri yokomisa ngokukghadzisa ukudla yathoma begodu njenganje ngabo 2020s, imikhiqizo eyonyiswe ngokukghadziswa ifaka hlangana iinthelo, inyama kunye neenselo eziselwa ngesikhatheso nokudla okuvuthele futhu kwabantu abakhempako, iingabaza, amajoni kunye nabosomkhathi.
Indlela Yokwenza Yokomisa Ngokukghadzisa
Igama elibizwa nge-technical term yokomisa ngokukghadzisa yi-lyophilization.
Ukomisa ngokukghadzisa yindlela yokwenza lapho amanzi (nofana i-suspension medium) ibamarhalasi emazingeni wamakhaza aphasi bekasuswe nge-sublimation. I-Sublimation kulapho amanzi atjhuguluka khona ekubeni yirhwaba aye esigabeni sokuba yirhasi (vapour) ngaphandle kokuncibilika nokuba mamanzi.
I-Sublimation ekambisweni yokwenza yokomisa ngokukghadzisa ingahlathululwa ngeentepu ezithathi; ukukghadzisa, ivakhyumu kunye nokomisa.
Esitepini sokuthoma sekambiso yokwenza yokomisa ngokukghadzisa, umkhiqizo ukghadziswa khulu ngaphasi kwegandeleleko elijayelekileko. Kuqakathekile ukukghadzisa ukudla msinya. Ukukghadzisa ukudla buthaka kubanga amarhalasi werhwaba amakhulu okona ukubumbheka kwama-cell wangaphakathi bekube nemithelela emimbi ekhwalithini yomkhiqizo wekugcineni.
Isitepu sesibili kufaka umkhiqizo okghadzisiweko ngaphasi kwevakhyumu bese kwesithathu, umtjhiso uyafakwa ukunikela amandla wokutjhugulula irhwaba libe yi-vapour. I-water vapour ibuthelelwa ngeentjhubisi ezikhethekileko. Isigabesi sokomisa sisusa amanzi angaba yi-95% begodu singathatha ama-awara angasuka kwambalwa ukuya emalangeni amabili. Indlela yokwenza yesibili yokomisa enamazinga akhuphukileko isusa ama-molecules wamanzi angakakghadziswa emikhiqizweni.
Ukudla okonyiswe ngokukghadziswa esele kuprosesiwe bekwafika ekugcineni kumumethe amanzi angaba yi-1% kunye ne-4%. Ukomisa ngokukghadzisa okulawulwa kuhle kutjhiya izakhamzimba ezinengi zingakathindeki begodu kubangela ukutjhuguluka okuncani esakhiweni sangaphakathi sokudla. Ama-cells onyisiweko ngaphakathi komkhiqizo kwanjesi abanesakhiwo esifana nesesipontji esimumatha amanzi khulu lokha umkhiqizo nawuthanjiswako.
Ngemva kokomisa ngokukghadzisa, imikhiqizo yokudla ipakiwa eenkhwameni nofana emakotikotini athelwa ngerhasi ye-nitrogen ukususa umoya.
Ukudla Okonyiswe Ngokukghadziswa
Iimbonelo zokudla okonyiswe ngokukghadziswa zifaka hlangana inyama, ama-spices, ibisi lephawuda, itjhizi, amaqanda, iinthelo kunye neenselo eziselwa ngemva kokwenziwa ezifana nama-gruneles wekofi, itiye kunye nama-smoothies. Iinthelo zenza isiquntu esinengi (esingaphezulu kuka-30%) semakethe yokomisa ngokukghadzisa, kodwana ngokungezelelweko ukudla okuphekelwe futhi okufaka hlangana ama-pasta, iinsobho, i-stew kunye nezehliso.
Iinthelo kunye nenyama zisikelelwa zibe ziintoki ezincani ngaphambili kobana zonyiswe ngokukghadziswa begodu zitholakale nangomhlobo we-chunk eyomisiwe ngokukghadziswa nofana i-mince. Inyama, ukudla kwelwandle nokhunye ukudla okulungele ukudliwa kuyaphekwa ngaphambili kobana konyiswe ngokukghadziswa begodu kudinga ukuthelwa amanzi kwaphela lokha nakuphekwako.
Iinzuzo Zokomisa Ngokukghadzisa
Ukomisa ngokukghadzisa kubulunga umnambitho, umbala, isakhiwo kunye nokuqaleka komkhiqizo wokudla bekwehlise nokonakala kwezakhamzimba ezisaba umtjhiso. Iinhlahlubo zihlole ukudla okonyisiweko ngeendlela ezihlukeneko zokomisa- i-convective, ivakhyumu, ukukghadzisa kunye ne-osmotic drying - zafunyana umnambitheko omnandi emikhiqizweni eyonyiswe ngokukghadziswa.
Imikhiqizo eyonyiswe ngokukghadzisa esikhathini esinengi i-crisper begodu ineretjhiyo yokuthamba godu encono ngokuphindaphindwe kane ukuya amahlandla asithandathu (ingamunya amanzi amanengi) kunemikhiqizo yokudla eyonyiswe ngomoya. Kunezakhamzimba, kumnandi begodu akusibudisi - kulungele ipilo yabantu abathanda ukuzibandakanya emidlalweni yezehlakalo ezingakajayeleki ama-adventure-style sport begodu kulula nokobana kuthuthwe lokha nakunezehlakalo eziphuthumako.
Ngokungezelela, ukomisa ngokukghadzisa kungezelela isikhathi sokobana imikhiqizo efretjhi ihlale isikhathi eside ingaboli msinya begodu nokudla okungahlala iinyanga ezihlangana kweziyi-3 ukuya 6 nazikuma-polybags bona kuphethe kuhlala iminya engaphezulu kuka-25 kungaboli lokha nakusemakotikotini.
Iindleko ngizo ezimraro omkhulu lokha naziza ekomiseni ngokukghadzisa ngonobangela wamandla aphezulu adingekako kunye nokutjhejwa kwawo.
Translated by Busisiwe Skhosana