Title Određivanje krioprotektorske djelotvornosti trehaloze na različite uzorke mesa Title (english) Determination of cryoprotective effects of trehalose on different meat samples Author Krešimir Mastanjević Mentor Dragan Kovačević (mentor)Committee member Drago Šubarić (predsjednik povjerenstva)Committee member Dragan Kovačević (član povjerenstva)Committee member Vesna Lelas (član povjerenstva)Committee member Srećko Tomas (član povjerenstva)Granter Josip Juraj Strossmayer University of Osijek Defense date and country 2010-05-18, Croatia Scientific / art field, BIOTECHNICAL SCIENCES Universal decimal classificationUDC ) 664 - Production and preservation of solid foodstuffs Abstract U ovoj disertaciji, pomoću diferencijalne motridbene kalorimetrije (DSC) i metodom određivanja topljivosti u otopinama soli (SEP-metoda), određivana je krioprotektorska djelotvornost tijekom jednogodišnjeg skladištenja smrznutih uzoraka goveđeg i pilećeg mesa koje je prethodno iskošteno, usitnjeno, višestruko isprano destiliranom vodom te u različitim masenim omjerima pomiješano s trehalozom (w = 0, 2, 4, 6, 8 i 10%). Mjerenja DSC-om i SEP-metodom su provedena sa svim uzorcima goveđeg i pilećeg mesa neposredno nakon pripreme uzoraka te nakon 30, 90, 180 i 360 dana skladištenja u smrznutom stanju pri -30 oC. Također, radi uspredbe, na isti način (maseni udjeli, uzorci i vremenski intervali) provedeni su i eksperimenti s disaharidom maltozom. Na osnovi eksperimentalnih rezultata predloženi su korelacijski (matematički) modeli ovisnosti vrijednosti entalpija denaturacije (DSC) i koncentracija (SEP) miofibrilarnih proteina o vremenu skladištenja, vrsti mesa te masenim udjelima trehaloze i maltoze. Također, predloženi su i korelacijski modeli ovisnosti temperature denaturacije miofibrilarnih proteina (aktina i miozina) o masenim udjelima trehaloze i maltoze i vrsti mesa pri različitim intervalima skladištenja. Entalpije denaturacije miozina (ΔHm) uzoraka pilećeg i goveđeg mesa pri svim vremenskim intervalima skladištenja i pri svim masenim udjelima trehaloze i maltoze pokazuju značajnije povećanje u odnosu na entalpije denaturacije aktina (ΔHa ) što upućuje na zaključak da trehaloza i maltoza imaju bolji krioprotektorski učinak na miozin. Uspoređujući vrijednosti entalpija denaturacije miozina i aktina (ΔHm i ΔHa) uzoraka pilećeg i goveđeg mesa s dodatkom maltoze i trehaloze, neovisno o vremenu skladištenja i masenom udjelu, uzorci s dodatkom trehaloze pokazuju veće vrijednosti entalpije što upućuje na zaključak da trehaloza ima bolja krioprotektorska svojstva od maltoze. Vrijednosti entalpije denaturacije aktina i miozina (ΔHm i ΔHa) uzoraka pilećeg mesa s dodatkom trehaloze i maltoze, neovisno o vremenu skladištenja i masenim udjelima, pokazuju veće vrijednosti u odnosu na uzorke goveđeg mesa što upućuje na zaključak da trehaloza i maltoza imaju bolji krioprotektorski učinak na aktin i miozin pilećeg mesa. Povećanje vrijednosti koncentracija miofibrilarnih proteina dobivenih SEP-metodom uzoraka pilećeg i goveđeg mesa posljedica je krioprotektorskog djelovanja maltoze i trehaloze na miofibrilarne proteine goveđeg i pilećeg mesa. Koncentracije miofibrilarnih proteina povećavaju se povećanjem masenog udjela maltoze i trehaloze. Rezultati dobiveni SEP-metodom sukladni su rezultatima mjerenja s DSC-om i potvrđuju da trehaloza i maltoza imaju krioprotektorska svojstva, da je trehaloza djelotvorniji krioprotektor od maltoze te da trehaloza i maltoza imaju bolji krioprotektorski učinak na miofibrilarne proteine pilećeg mesa.
Abstract (english) In this dissertation, the cryoprotective effects of trehalose on beef and chicken meat, which has been deboned, minced and multiple washed with distilled water and in different mass fractions (w = 0, 2,4, 6, 8, 10%) mixed with trehalose, during one year of frozen storage by the use of differential scanning calorimetry (DSC) and salt extractable protein (SEP). DSC and SEP measurements of chicken and beef meat sample were conducted immediately after preparation and subsequently after 30, 90, 180 and 360 days of frozen storage on -30 ºC. Also for comparison, the same experiments (mass fractions, samples and time intervals) were conducted with disaccharide maltose. Based on experimental results mathematical (correlation) models of dependency of denaturation enthalpies (DSC) and protein concentrations (SEP) of myofibrillar proteins with frozen storage time and mass fractions of trehalose and maltose and meat origin were calculated. Also, mathematical (correlation) models of dependency of denaturation temperature (Tp) of myofibrillar proteins (actin and myosin) of mass fraction of trehalose and maltose on different frozen storage intervals were calculated. Myosin denaturation enthalpies (∆Hm), of chicken and beef samples for all storage time intervals and all mass fractions of trehalose and maltose, showed higher increase, then increase of actins denaturation enthalpies (∆Ha ), which leads to conclusion that both sugars have better cryoprotectve effect on myosin. Comparing the myosin and actins denaturation enthalpies (∆Hm and ∆Ha), of chicken and beef samples for all storage time intervals, with addition of trehalose and maltose, samples mixed with trehalose showed higher values of denaturation enthalpies, which leads to conclusion that tresalose showed better cryoprotective properties than maltose. Myosin’s and actins denaturation enthalpies (∆Hm and ∆Ha) of chicken samples, regardless of mass fraction of trehalose and maltose and storage time intervals, showed higher values of denaturation enthalpies, which leads to conclusion that trehalose and maltose had better cryoprotectve effect on chickens myosin and actin. Increase of myofibrillar protein concentration determined by SEP-method of chicken and beef samples is a result of cryoprotective effect of trehalose and maltose. Myofibrillar protein concentration showed increase with increase of mass fraction of trehalose and maltose. The results determined by SEP-method confirmed DSC results and approved that both trehalose and maltose had cryoprotective effects, that trehalose is better cryoprotective agent and trehalose and maltose had better cryoprotectve effect on chicken’s myofibrillar proteins.
Keywords
proteini
meso
pileće meso
goveđe meso
trehaloza
maltoza
DSC
SEP
Keywords (english)
proteins
meat
chicken meat
beef meat
trehalose
maltose
DSC
SEP
Language croatian URN:NBN urn:nbn:hr:109:759785 Project Number: 113-1130473-0571 Study programme Title: Food Engineering Catalog URL http://161.53.208.100/cgi-bin/lb10/unilib.cgi?form=D1100111031 Type of resource Text Extent 184 str.; ilustr., graf. prikazi; 30 cm File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2016-02-02 10:04:28
