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Kinetics of combined dryingquince (Cydonia oblonga Mill.)

dc.contributor.advisorBabić, Mirko
dc.contributor.otherBabic, Ljiljana
dc.contributor.otherVeličković, Milovan
dc.contributor.otherBabić, Mirko
dc.creatorStojanović, Čedomir
dc.date.accessioned2017-10-30T14:39:18Z
dc.date.available2017-10-30T14:39:18Z
dc.date.available2020-07-03T13:34:32Z
dc.date.issued2014-06-25
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/8710
dc.identifier.urihttp://www.cris.uns.ac.rs/DownloadFileServlet/Disertacija139454034991296.pdf?controlNumber=(BISIS)85685&fileName=139454034991296.pdf&id=1517&source=NaRDuS&language=srsr
dc.identifier.urihttp://www.cris.uns.ac.rs/record.jsf?recordId=85685&source=NaRDuS&language=srsr
dc.identifier.urihttp://www.cris.uns.ac.rs/DownloadFileServlet/IzvestajKomisije139454036001620.pdf?controlNumber=(BISIS)85685&fileName=139454036001620.pdf&id=1518&source=NaRDuS&language=srsr
dc.description.abstractSušenje dunje kao voćne vrste u praksi nije uobičajeno, zbog povišene vrijednosti tvrdoće i čvrstoće. Prethodna istraživanja sušenja dunje, pokazala su da se osmotskim sušenjem u okviru kombinovane tehnologije sušenja dobijaju povoljnije mehaničke osobine sušenih proizvoda. Na osnovu plana obavljeni su eksperimenti osmotskog i konvektivnog sušenja dunje u obliku četvrtina. Eksperiment osmotskog sušenja je obavljen kao trofaktorni, gdje su uticajni faktori: temperatura rastvora, koncentracija rastvora i vrijeme trajanja sušenja. TakoĎe, eksperiment konvektivnog sušenja je obavljen kao trofaktorni, a uticajni faktori su: primjenjeni predtretman, temperature vazduha za sušenje i brzina strujanja vazduha ispred sloja. Na osnovu rezultata mjerenja eksperimenta osmotskog sušenja, zaključeno je da sa porastom temperature i koncentracije rastvora postiže se veća brzina sušenja, što se i očekivalo. Disperzionom analizom osmotskog sušenja je ispitan uticaj faktora na brzinu sušenja i zapreminsko skupljanje četvrtina dunje. Sa statističkom vjerovatnoćom od 99% je dokazano da postoji uticaj svih faktora na brzinu sušenja uzoraka. Dokazano je sa statističkom vjerovatnoćom od 99% da vrijeme trajanja osmotskog sušenja ima uticaj na zapreminsko skupljanje četvrtina dunje, dok uticajni faktori temperatura i koncentracija rastvora imaju uticaj sa statističkom vjerovatnoćom od 95%. Analizom rezultata mjerenja veličina tokom eksperimenta konvektivnog sušenja evidentno je da se sa višom temperaturom vazduha postiže brže sniženje vlažnosti četvrtina dunje. Povećanjem vremena trajanja osmotskog predtretmana, smanjuje se brzina konvektivnog sušenja. UtvrĎeno je da korišćenje osmotskog predtretmana sa višom temperaturom rastvora i većom koncentracijom rastvora dovodi do smanjenja brzine konvektivnog sušenja. Na osnovu disperzione analize konvektivnog sušenja sa statističkom vjerovatnoćom od 99% dokazano je da postoje uticaji predtretmana i temperature vazduha na brzinu sušenja i zapreminsko skupljanje četvrtina dunje. Uticaj faktora brzine vazduha ispred sloja materijala nije dokazan disperzionom analizom, ali je na osnovu kinetički krivih evidentan uticaj ovog faktora na brzinu sušenja, pri višim vlažnostima materijala i višoj temperaturi konvektivnog sušenja. Najvjerovatniji razlog ovakvih rezultata disperzione analize su male vrijednosti brzine vazduha za sušenje, odnosno njihova mala razlika vrijednosti (0,5 m/s). Kinetika prenosa mase tokom kombinovane tehnologije sušenja dunje u formi četvrtine je matematički opisana, modelovanjem kinetike osmotskog sušenja i kinetike konvektivnog sušenja. U okviru kinetike osmotskog sušenja četvrtina dunje, obavljeno je matematičko modelovanje promjene vlažnosti u odnosu na suvu bazu i modelovanja zapreminskog skupljanja. Za kinetiku konvektivnog sušenja četvrtina dunje, obavljeno je matematičko modelovanje promjene vlažnosti u odnosu na suvu bazu tokom vremena konvektivnog sušenja. Za svaku veličinu koja se modeluje usvojeno po tri matematička modela, a modeli su prošireni uticajnim faktorima u bezdimenzionom obliku. Izvedeni modeli su imali dobro slaganje sa eksperimentalnim rezultatima, što pokazuju visoke vrijednosti koeficijente korelacije. Primjena svih modela je jednostavna, gdje je uz pomoć standardnih računara moguće brzo izračunavanje svih modelovanih veličina. Primjenom osmotskog predtretmana u kombinovanoj tehnologiji sušenja dunje, dobijaju se neke pozitivne osobine sušenog proizvoda. Smanjenje zapremine je manje izraženo, nego primjenom samo konvektivnog sušenja. Vlažnost u voćnom tkivu je ravnomjernije rasporeĎena i manje je presušivanje spoljnjih slojeva voćnog tkiva. Stvaraju se manji unutrašnji naponi izmeĎu slojeva tkiva, uslijed čega nastaju manje deformacije oblika. U površinskom sloju voćnog tkiva postoje adsorpcione veze vlage, rastvorka i suve materije, a ove veze utiču na povećanje vrijednosti vlažnosti pri kojima se osušeni proizvod bezbjedno skladišti.sr
dc.description.abstractDrying of the quince as a fruit species is not common in practice due to its increased hardness and firmness. Previous researches on quince drying have indicated that osmotic drying, within the combined drying technology, enables favourable mechanical properties of dried products. Planned experiments of the osmotic and convective drying of quince quarters were conducted. The osmotic drying experiment was based on three significant experimental factors: the temperature of osmotic solution, the concentration of osmotic solution, and the duration of osmotic drying. The convective drying experiment was also based on three experimental factors entailing the applied pretreatment, the temperature of drying air and the velocity of drying air in front of material layers. The measurement results obtained during the osmotic drying experiment indicate that an increase in the temperature and the concentration of osmotic solution accelerates the drying process, as expected. A dispersion analysis of the osmotic drying indicated the effects of experimental factors on the drying speed and the volume shrinkage of quince quarters. With a statistical probability of 99%, it was proven that all factors influence the speed of drying. Moreover, with a statistical probability of 99%, it was proven that the duration of osmotic drying influences the volume shrinkage of quince quarters, whereas the significant factors such as the temperature and the concentration of osmotic solution exert influence with a statistical probability of 95%. The analysis of measurement results obtained during the convective drying experiment shows that an increase in the air temperature accelerates a decrease in the moisture content of quince quarters. An increase in the duration of osmotic pretreatment decelerates the convective drying process. It was determined that the application of the osmotic pretreatment with higher solution temperature and concentration decelerates the convective drying. On the basis of a dispersion analysis of the convective drying with a statistical probability of 99%, it was proven that the pretreatment and the air temperature affect the speed of drying and the volume shrinkage of quince quarters. The effects of the air velocity in front of the material layer was not determined by means of the dispersion analysis, nevertheless kinetic curves indicate the influence of this factor on the drying speed, especially in the instance of higher moisture content of the material and higher temperature of the convective drying. The most probable causes of such dispersion analysis results are low values of the drying air velocity, i.e. a slight difference in the values (0.5 m/s). The kinetics of mass transfer during the combined drying of quince quarters was mathematically described by means of the modelling of the kinetics of osmotic drying and the kinetics of convective drying. The kinetics of osmotic drying of quince quarters was expressed via the mathematical modelling of moisture content change in relation to dry basis and the modelling of volume shrinkage. The kinetics of convective drying of quince quarters was expressed via the mathematical modelling of moisture content change in relation to dry basis during the convective drying. Three mathematical models were established for every modelled value, and the models were extended by significant non-dimensional experimental factors. The developed models had a good fit with the experimental results, which was indicated by the high values of the correlation coefficient. The application of all models is simple and standard personal computers can be used for rapid calculations of modelled values. The application of the osmotic pretreatment in the combined quince drying enables favourable properties of dried products. Volume shrinkage is slighter in comparison with the convective quince drying. The moisture content in the fruit tissue is more evenly distributed and the dehydration of the outer layers of the fruit tissue is lower. The tension between the layers of the tissue is reduced thus reducing the shape defects. Within the surface layers of fruit tissues, the adsorption bonds of moisture, solute and dry matter are formed. These bonds increase the moisture content value, which enables the safe storage of dry products.en
dc.languagesr (latin script)
dc.publisherУниверзитет у Новом Саду, Пољопривредни факултетsr
dc.rightsopenAccessen
dc.sourceУниверзитет у Новом Садуsr
dc.subjectKombinovano sušenjesr
dc.subjectCombined dryingen
dc.subjectkinetika sušenjasr
dc.subjectdunjasr
dc.subjectosmotsko sušenjesr
dc.subjectkonvektivno sušenjesr
dc.subjectmatematičko modelovanjesr
dc.subjectdrying kineticsen
dc.subjectquinceen
dc.subjectosmoticdryingen
dc.subjectconvective dryingen
dc.subjectmathematical modellingen
dc.titleKinetika kombinovanog sušenja dunje (Cydonia oblonga Mill.)sr
dc.title.alternativeKinetics of combined dryingquince (Cydonia oblonga Mill.)en
dc.typedoctoralThesissr
dc.rights.licenseBY-NC
dcterms.abstractБабић, Мирко; Бабиц, Љиљана; Величковић, Милован; Бабић, Мирко; Стојановић, Чедомир;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/36476/IzvestajKomisije13360.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/36475/Disertacija13360.pdf


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