Ukubiliswa kokutya (pasteurisation) kwaqalwa ngu Louis Pastueur, ingcaphephe yase France. Wafumanisa okokuba ukubilisa ubisi kubushushu obuphezulu ze ulipholise emveni koko phambi kokuba ulifake ezimbhodleleni okanye ulipakishe kungalenza luhlale ixesha elide.
Exesheni wahamba wayokusebenza ngebhiya, ze kunyaka ka 1873 waqhubeka ngoku bilisa ibhiya.
Kodwa ke, ukubilisa akulilo iyeza lobuxelegu kunye nezenzo ezingaphucukanga, lilonke ke ukhuseleko lokutya nemigqaliselo nolawulo lomgangatho zibaluleke kakhulu xa kulungiswa ukudla okuse hlaza.
Ngeminyaka yama 1800s, ubisi olusuka kwizi lwanyana ezigulayo, olusengelwe kwindawo emdaka, kwadala ukufa kwamawaka abantu. Ngeloxesha amafama aqonda okokuba ukubilisa ubisi oluselwa ngamankonyane kwehlisa isifo sephepha kwimihlambi.
Yintoni Ukubilisa
Ukubilisa kukuba ubushushu bubephakathi ko (60 -100°C) wamanzi okanye okwenziwe ngamanzi okanye ukutya imizuzu embalwa phambi kokuba kuphiliswe. Ukubilisa kubulala iintsholongwane nezifo ezenza iintsholongwane ezifana ne Salmonella, Listeria, Escherichia coli O 157:H7 kunye ne Staphylococcus aureus.
Indlela Yokubilisa
Ubushushu kunye nexesha lokubilisa zixhomekeka kuhlobo lokutya kunye nendlela yokupakisha. Ukutya okunokuthi kubiliswe kuquka iimveliso zobisi, amaqanda, isiselo se jusi, isayida kunye nebhiya, ukutya ikosher, iwayini, amandongomane, umgubo we flawa, kunye nobusi.
Ezinye zemveliso ezifana nesiselo se jusi kunye ne wayini zidinga ukuba semoyeni, ngexesha ubisi okokuba kohlulwe ubusi ne krimu phambi kokuba lubiliswe.
Indlela eqhelekileyo yokubilisa ubisi ichazwe ngezantsi:
Indlela yokubilisa iquka ukubilisa ubisi kubushushu obungama 72°C imizuzu eyi 15 seconds kodwa ingadluli ku 25 seconds. Ubisi luyapholiswa emveni koko ngaphantsi ko 3°C emveni koko lipakishwe. Isixhobo ezisetyenziswa ukubilisa nokupholisa ubisi sibizwa ngokuba ‘kukutshintshana kobushushu’. Esokubilisa ibizwa ngokuba yi ‘High Temperature Short Time’ (HTST).
Ukudibana Kobisi ne Krimu
Elinyathelo lenzeka emveni kokubilisa ubisi. Yindlela esebenzisa ubushushu ethi incede ukusasaza amafutha ngobisi lungenzi ucwambu ngaphezulu.
Ukubilisa nge Microwave
Ukutya okufana namaqanda kubiliswa nge microwave. Ixesha lokubilisa ukutshabalalisa iintsholongwane E.coli ne Staphylococcus aureus limalunga ne 30 seconds, ngexesha ukutshabalalisa Bacillus cereus idinga ama 90 seconds.
Indlela yokubulala iintsholongwane iquka ukulungisa ukutya okufana nesonka, nge microwave, isebenzisa amandla wombane (radio frequencies) kwi microwave. Ibulala imingxuma eyenza kukhule ukungunda kwisonka kwaye ngalendlela, yenza isonka singabi nako ukungunda ukuyokuma kwintsuku ezingama 60.
Imicrowave yase khaya ne oveni akufunekanga okokuba kuxhomekekwe kuzo ukutshabalalisa iintsholongwane.
Ukubulala Intshlongwane Ngendlela Ebandayo
Ezinye iindlela ziquka High-Pressure Processing (HPP), Pulsed Electric Fields (PEF) nemibono kunye nobuchwepheshe be membrane technology.
Ngexesha lokubulala iintsholongwane, iimveliso ezivalelekileyo (esele zipakishiwe) zipakishwa kwi khonteyina kwaye kubushushu obungapha ko 6 000 bar. Oku kwenza iintsholongwane zingasebenzi kwaye yandise nobomi bemveliso. Lemveliso ingaba zindlela ze HPP ezithi zenziwe kukutya okulungele ukutyiwa, ukutya kwezilwanyana, salsa, guacamole kunye diphu kunye ne jusi, ubisi nemveliso zengqolowa.
I-PEF itshabalalisa iintsholongwane (ngokuthi ichaphazele i-cell membranes) ngaphandle kokuba ichaphazele umbala wemveliso, incasa, kunye nezinongo. PEF ayikwazi ukwenza iintsholongwane zingafi, yiyo lonto ingalunganga ukusetyenziswa njenge ndlela yokubulala intsholongwane.
Ukubilisa nge ultrasound kusetyenziswa ukususa iintsholongwane ekutyeni nakwizixhobo ezisetyenizswa esibhedlele kwaye ingasetyenziswa ne (thermal pasteurisation) yobisi, ibhiya, kunye neemveliso zamaqanda ezimanzi.
Ukutya okuqinileyo iintsholongwane zibulalwa ngelanga elinamazinga aphantsi wemitha yelanga ye gamma, X-rays ne electrons ukulawula iintsholongwane ekutyeni.
Pasteurisation ne UHT
Ixesha elininzi, imibhalo yokutya epakishiweyo iibhalwa ‘pasteurise’ okanye ‘UHT’ – igama elifutshane le ‘Ultra High Temperature’. Yintoni umahluko phakathi kwe pasteurisation okanye UHT?
Ubushushu bokubulala iintsholongwane buba ko 71°C nge 15 seconds phambi kokuba iphole ku 3°C. UHT ibilisa imveliso ukuya ku 137°C isekondi ezimbini phambi kokuphola.
Zombini ezindlela zisetyenziswa ukutshabalalisa ezenza umonakalo.
Inzuzo ye Pasteurisation
I-Pasteurisation ivalela ukungcoliseka kokutya kwi femu kwaye yandisa ubomi bemveliso. Kanjalo, indlela yokutshisa yokubulala iintsholongwane itshintsha ubungakanani bezinongo ngendlela ezingatyekiyo.
Translated by Zikhona Plaatjie