Mahlade tootmisel kasutatavad immobiliseeritud hüdrolüütilised ensüümid
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Kuupäev
2024
Kättesaadav alates
13.09.2024
Autorid
Aunbaum, Anete
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Toiduainetööstuses kasutatakse pektinolüütilisi ja tsellulaasseid ensüümpreparaate, mis lisatakse mahla valmistamisel purustatud marjamassile, et vähendada peamiselt mahla viskoossust ja hägusust. Käesolevas töös immobiliseeriti nailon 6/6-kandjale nii pektinaasi kui ka tsellulaasi ensüüme ning hinnati kasutatud ensüümelementide aktiivsust, stabiilsust ja tööiga mustsõstramahlas.
Ensüümelementide valmistamiseks immobiliseeriti ensüümid raamile keritud 8 m pikkustele nailon 6/6-niitidele kasutades dimetüülsulfaati ja glutaaraldehüüdi. Immobiliseeritud ensüümide katalüütilise aktiivsuse määramine viidi läbi viskosimeetrilise meetodi abil, kuna võrreldes spektrofotomeetrilise meetodiga oli see lihtsam, täpsem, kiirem ja parema korratavusega. Nelja pektinaasipreparaadi seast valiti immobiliseerimiseks Pectinex Ultra Mash, kuna selle pektinolüütiline aktiivsus oli kõige suurem.
Ensüümelementide keskmine pektinolüütiline aktiivsus oli esimesel mõõtmiskorral 0,18±0,001 U ning kümnendal kasutuskorral oli säilinud 27% esialgsest aktiivsusest. Ilma kasutamata püsis pektinolüütiline aktiivsus kuu aja vältel stabiilsena nii toatemperatuuril kui ka 4 °C juures naatriumatsetaatpuhvris. Tsellulaasne aktiivsus oli algselt 0,63±0,002 U ning 46.päeval oli säilinud 37% esialgsest aktiivsusest. Mustsõstramahlas säilis pektinolüütilisest aktiivsusest 5 kuu möödudes 55%, tsellulaassest aktiivsusest säilis peale nelja kasutuskorda 44% esialgsest. Ehkki ensüümelementide pektinolüütiline kui ka tsellulaasne aktiivsus mustsõstramahlas aja jooksul vähenes, on saadud tulemused heaks eelduseks immobiliseeritud ensüümide kasutamiseks.
In the food production, pectinolytic and cellulolytic enzyme preparations are used. These are added to the berry mash during juice preparation, primarily to reduce the viscosity and turbidity of the juice. In this present study, both pectinase and cellulase enzymes were immobilized on nylon 6/6 carriers and the activity, stability and reusability of the used enzyme elements were evaluated in blackcurrant juice. To prepare enzyme elements, enzymes were immobilized on the 8 m long nylon 6/6 thread carriers using dimethyl sulfate and glutaraldehyde. The catalytic activity of the immobilized enzymes was determined viscosimetrically because it was simpler, more accurate, faster and with better repeatability compared to the spectrophotometric method. Among the four pectinase preparations, Pectinex Ultra Mash was chosen for immobilization due to its highest pectinolytic activity. The average pectinolytic activity of the enzyme elements was 0.18±0.001 U at the first measurement, and 27% of the initial activity was retained after the tenth use. Without use, the pectinolytic activity remained stable for one month both at room temperature and at 4 °C in sodium acetate buffer. The initial cellulolytic activity was 0.63±0.002 U, and 37% of the initial activity was retained on the 46th day. In blackcurrant juice, 55% of the pectinolytic activity was retained after 5 months, and 44% of the initial cellulolytic activity was retained after four uses. Although both the pectinolytic and cellulolytic activity of enzyme elements in blackcurrant juice decreased over time, the obtained results present a promising prospect for the use of immobilized enzymes.
In the food production, pectinolytic and cellulolytic enzyme preparations are used. These are added to the berry mash during juice preparation, primarily to reduce the viscosity and turbidity of the juice. In this present study, both pectinase and cellulase enzymes were immobilized on nylon 6/6 carriers and the activity, stability and reusability of the used enzyme elements were evaluated in blackcurrant juice. To prepare enzyme elements, enzymes were immobilized on the 8 m long nylon 6/6 thread carriers using dimethyl sulfate and glutaraldehyde. The catalytic activity of the immobilized enzymes was determined viscosimetrically because it was simpler, more accurate, faster and with better repeatability compared to the spectrophotometric method. Among the four pectinase preparations, Pectinex Ultra Mash was chosen for immobilization due to its highest pectinolytic activity. The average pectinolytic activity of the enzyme elements was 0.18±0.001 U at the first measurement, and 27% of the initial activity was retained after the tenth use. Without use, the pectinolytic activity remained stable for one month both at room temperature and at 4 °C in sodium acetate buffer. The initial cellulolytic activity was 0.63±0.002 U, and 37% of the initial activity was retained on the 46th day. In blackcurrant juice, 55% of the pectinolytic activity was retained after 5 months, and 44% of the initial cellulolytic activity was retained after four uses. Although both the pectinolytic and cellulolytic activity of enzyme elements in blackcurrant juice decreased over time, the obtained results present a promising prospect for the use of immobilized enzymes.
Kirjeldus
Magistritöö
Toiduainete tehnoloogia õppekaval
Märksõnad
magistritööd, ensüümi immobiliseerimine, tsellulaasne aktiivsus, pektinolüütiline aktiivsus, nailon 6/6-kandja, stabiilsus, Roheline Ülikool (töö toetab EMÜ Rohelise Ülikooli põhimõtteid), keskkonnateadvus, keskkonnaharidus