Utjecaj različitih režima toplinske obrade na kvalitetu kobiljeg mlijeka

master's thesis

• Title (english): Influence of different heat treatments regimes on mare`s milk quality
• Author: Ivana Blažević
• Mentor: Irena Barukčić Jurina (mentor)
• Committee member: Katarina Lisak Jakopović (predsjednik povjerenstva)
• Committee member: Tamara Jurina (član povjerenstva)
• Committee member: Ksenija Marković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Milk and Milk Products); Zagreb
• Defense date and country: 2022-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Kobilje mlijeko je oduvijek bilo cijenjena namirnica zbog brojnih terapeutskih svojstava. Kako bi se očuvao jedinstven nutritivni sastav, kobilje mlijeko najčešće se konzumira sirovo ili se smrzava. Cilj ovog rada bio je ispitati utjecaje različitih toplinskih tretmana na kvalitetu kobiljeg mlijeka. Pri tom je praćena koncentracija hidroksimetilfurfurala (HMF) nastalog uslijed toplinske obrade, antioksidacijska aktivnost (AA) pomoću DPPH i FRAP metoda te udjel ukupnih fenola Folin Ciocalteu metodom. SDS-PAGE elektroforezom je praćena denaturacija proteina, dok je blisko-infracrvena spektrometrija (NIR) korištena za kvalitativnu analizu struktirnih promjena u uzorcima mlijeka. Dobiveni rezultati ukazuju kako povišenje temperature i/ili duže trajanje toplinske obrade uzrokuje povećanje koncentracije HMF-a, ukupnih fenola i AA mjerene FRAP metodom, dok je AA mjerena DPPH metodom padala. Nadalje, povećanjem intenziteta toplinskog režima smanjivale su se vrijednosti ukupnih otopljenih tvari i električne vodljivosti. SDS-PAGE elektroforeza je ukazala na denaturaciju nekih proteina. Analiza glavnih komponenata dobivenih NIR spektara pokazala je sličnosti među određenim uzorcima u odnosu na primijenjen toplinski režim.

Abstract (english)

Mare milk has always been a highly appreciated due to its therapeutic characteristics. In order to maintain a unique nutritive profile, mare milk is usually consumed raw or it is frozen. The aim of this study was to examine the effects of different heat treatments on mare milk quality. Thereby following parameters were determined: hydroxymethylfurfural (HMF) concentration, antioxidant activity (AA) by the DPPH and FRAP method, and the total phenol content by the Foline Ciocalteu method. SDS-PAGE electrophoresis was used to monitor protein denaturation while Near Infrared Spectroscopy (NIR) for qualitative analysis of structural changes in milk samples. According to the obtained results, with time and/or temperature increase the concentrations of HMF, AA (FRAP) and total phenols content increased too, while AA measured by the DPPH method, total dissolved solids and electrical conductivity decreased. SDS-PAGE electrophoresis indicated denaturation of some proteins. Principal Component Analysis of NIR spectra revealed similarities between the tested samples in relation to the applied thermal regime.

• Keywords: kobilje mlijeko; hidroksimetilfurfural; antioksidacijska aktivnost; fenolni spojevi; SDS-PAGE elektroforeza
• Keywords (english): mare milk; hydroxymethylfurfural; antioxidant activity; phenolic compounds; SDS-PAGE
• Language: croatian
• URN:NBN: urn:nbn:hr:159:800475
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-02-24 13:40:01