master's thesis
Kinetics of convection drying and rehydration frozen sour cherries "Oblačinske"

Leonard Kirić (2009)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Process Engineering
Sub-department of Unit Operations
Metadata
TitleKinetika konvekcijskog sušenja i rehidratacije smrznute "oblačinske" višnje
AuthorLeonard Kirić
Mentor(s)Srećko Tomas (thesis advisor)
Abstract
Istraživan je utjecaj temperature sušenja i različitih kemijskih postupaka prethodne obrade na kinetiku konvekcijskog sušenja i rehidratacije smrznute "Oblačinske" višnje, kao i izbor matematičkog modela za predviđanje kinetike sušenja i rehidratacije koji daje najbolje slaganje s dobivenim eksperimentalnim podacima. Uzorci višanja su prije zamrzavanja obrađeni s 0,5 %-tnom otopinom NaOH, 1 %-tnom otopinom askorbinske kiseline i 1 %-tnom otopinom pektolitičkih enzima (Lallzym Oe). Prvi dio pokusa imao je za cilj ispitivanje utjecaja različitih kemijskih postupaka prethodne obrade uzoraka višanja na kinetiku konvekcijskog sušenja pri konstantnoj temperaturi sušenja od 65 °C i brzini strujanja zraka od 2,5 m/s. U drugom dijelu pokusa praćen je utjecaj temperature sušenja (55 °C, 65 °C, 75 °C) na kinetiku sušenja i kinetiku rehidratacije uzoraka višanja, koji su prije zamrzavanja bili obrađeni s 0,5 %-tnom otopinom NaOH. Utjecaj različitih kemijskih postupaka prethodne obrade kao i utjecaj temperature sušenja na kvalitetu osušenih uzoraka višanja procijenjen je određivanjem rehidratacijeske sposobnosti sušenih uzoraka i određivanjem ukupne promjene boje sušenih i rehidratiranih uzoraka. Primjenjeni kemijski postupci prethodne obrade uzoraka višanja nisu imali značajniji utjecaj na kinetiku sušenja, dok je zamijećen njihov utjecaj na kinetiku rehidratacije. Najveći doseg rehidratacije postigli su uzorci obrađeni s 0,5 %-tnom otopinom NaOH te neobrađeni uzorci višanja. Temperatura sušenja imala je značajan utjecaj na kinetiku sušenja i rehidratacije. Pri višim temperaturama sušenja proces sušenja je bio brži, postignuta je veća brzina sušenja, skraćeno je vrijeme sušenja, te je ostvaren veći doseg rehidratacije i obrnuto. Usporedba matematičkih modela (Page, modificirani Henderson-Pabis i Peleg) za opisivanje kinetike sušenja i rehidratacije pokazala je da najbolje slaganje eksperimentalnih podataka i krivulja modela (za oba procesa) daje modificirani Henderson-Pabisov model: ɸ = G’· exp(-S’ · tN). Navedeni je model, za sve uzorke višanja imao najveće vrijednosti koeficijenta korelacije (R) čije su vrijednosti iznosile ~ 1, kao i najmanje vrijednosti (najbliže nuli) za ukupno kvadratno odstupanje (FL) i srednju relativnu pogrešku (P%) aproksimacije, što ukazuje na najbolje slaganje eksperimentalnih i izračunatih vrijednosti. Najveći doseg rehidratacije postigli su uzorci višanja obrađeni sa 0,5 %-tnom otopinom NaOH, te neobrađeni uzorci višanja. Najmanju ukupnu promjenu boje imali su uzorci višanja obradeni sa 1 %-tnom otopinom pektolitičkih enzima (Lallzym Oe).
Keywordscherry convection drying rehydration kinetics modeling previous processing color
Parallel title (English)Kinetics of convection drying and rehydration frozen sour cherries "Oblačinske"
Committee MembersBernarda Šeruga
Mate Bilić
Darko Velić
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Process Engineering
Sub-department of Unit Operations
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2009-02-26
Parallel abstract (English)
Explored the impact of drying temperature and various chemical processing procedures prior to the drying kinetics convection and rehydration frozen "Oblacinske" cherry, as well as the choice of mathematical models to predict the drying kinetics and rehydration that gives the best agreement with the obtained experimental data. Samples cherries are processed prior to freezing with 0,5 % NaOH solution, 1 % ascorbic acid solution and 1 % solution pektolitickih enzymes (Lallzym Oe). The first part of experiments was aimed at examining the influence of different chemical processes prior processing of samples of cherries on the kinetics convection drying at constant drying temperature of 65 °C and air flow speed of 2,5 m/s. In the second part of the experiments followed the influence of drying temperature (55 °C, 65 °C, 75 °C) on the kinetics of drying and the kinetics rehydration samples of cherries, which are freezing were treated with 0,5 % NaOH solution. Effect of different chemical processes prior treatment as well as the effect of temperature on the drying quality of the samples made from dry cherries has been assessed in determining rehydration capacity of dried samples and the determination of the total color changes of dried and rehydration samples. The chemical procedures applied prior treatment of samples did not have cherry significant influence on the kinetics of drying, while see their impact on the kinetics rehydration. The largest range rehydration as the samples treated with 0,5 % NaOH solution and raw samples of cherries. The temperature of drying had a significant influence on drying kinetics and rehydration. At higher temperatures drying process of drying was faster, achieved the higher drying rate, shortened the drying time, and has achieved greater reach rehydration and vice versa. Comparison of mathematical models (Page, modified Henderson-Pabis and Peleg) to describe the drying kinetics and rehydration showed that the best agreement of experimental data and model curves (for both processes) gives a modified Henderson Pabisov model ɸ = G’· exp(-S’ · tN). The above model, for all samples of cherries had the maximum value, correlation coefficient (R), whose value amounted to ~ 1, as well as a minimum value (the nearest zero) for a total of sigma (FL) and high relative error (P%) approximations, which indicates the best agreement of experimental and calculated values. The largest range rehydration achieved cherry samples processed with 0,5 % NaOH solution, and samples of raw tuna. Minimize the total color change had the tuna samples processed with 1 % solution pektolitickih enzymes (Lallzym Oe).
Parallel keywords (Croatian)višnja konvekcijsko sušenje rehidratacija modeliranje kinetike prethodna obrada boja
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:777900
CommitterSanda Hasenay