Analiza sirovog kravljeg mlijeka uzorkovanog u različitim stadijima mastitisa pomoću tehnika 1H i DOSY NMR

master's thesis

• Title (english): Analysis of raw cow's milk sampled in different stages of mastitis by applying 1H and DOSY NMR techniques
• Author: Matea Dupelj
• Mentor: Tomislav Jednačak (mentor)
• Committee member: Tomislav Jednačak (predsjednik povjerenstva)
• Committee member: Aleksandra Maršavelski (član povjerenstva)
• Committee member: Ivana Biljan (član povjerenstva)
• Committee member: Predrag Novak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2023-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Goveđi mastitis je upala mliječnih žlijezda koju najčešće uzrokuju razne patogene bakterije u
kombinaciji s ozljedom žljezdanog tkiva kravljeg vimena. Mastitis znatno utječe na sastav
mlijeka, jer dolazi do promjene u kvaliteti proteina, sastavu masnih kiselina, broju i vrsti
metabolita malih molekulskih masa te koncentraciji laktoze i minerala. Cilj ovog rada je
identificirati metabolite u kravljem mlijeku i usporediti sastav sirovog mlijeka zdravih krava
(2 skupine) te krava oboljelih od subkliničkog (4 skupine) i kliničkog mastitisa (1 skupina)
pomoću tehnika 1H i DOSY (engl. diffusion-ordered spectroscopy) NMR uz supresiju signala
otapala primjenom pulsnog slijeda NOESY (engl. nuclear Overhauser effect spectroscopy).
Asignirani su najintenzivniji signali u spektrima 1H NMR te su identificirani najvažniji
metaboliti u mlijeku. Analizom spektara DOSY NMR izračunate su vrijednosti translacijskih
difuzijskih koeficijenata za identificirane metabolite. Na temelju dobivenih podataka, pojedini
uzorci klasificirani su prema stadiju i uzročniku mastitisa. Na kraju su izračunate i uspoređene
vrijednosti translacijskih difuzijskih koeficijenata sastojaka mlijeka nakon pohrane uzoraka
pri sobnoj temperaturi u različitim vremenskim intervalima.

Abstract (english)

Bovine mastitis is an inflammation of mammary glands usually caused by various pathogenic
bacteria combined with the glandular tissue injury of the cow’s udder. Mastitis significantly
affects the milk composition, since it changes the protein quality, the fatty acid content, the
number and types of small molecule metabolites and the concentrations of lactose and
minerals. The goal of this thesis is to identify metabolites in cow’s milk and to compare the
composition of raw milk from healthy cows (2 groups) and from cows suffering from
subclinical (4 groups) and clinical (1 group) mastitis using 1H and DOSY (diffusion-ordered
spectroscopy) NMR techniques with NOESY (nuclear Overhauser effect spectroscopy)-type
solvent suppression. The most intense signals in 1H NMR spectra were assigned and the most
important metabolites in milk were identified. By analysing DOSY NMR spectra, the values
of translational diffusion coefficients for identified metabolites were calculated. Based on the
obtained data, individual samples were classified according to the stage and causative agent of
mastitis. Finally, the translational diffusion coefficients of milk constituents were calculated
and compared after storage of the samples at room temperature in different time intervals.

• Keywords: 1H NMR; DOSY; laktat; laktoza; mastitis; mlijeko
• Keywords (english): 1H NMR; DOSY; lactate; lactose; mastitis; milk
• Language: croatian
• URN:NBN: urn:nbn:hr:217:034950
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-09-13
• Created on: 2023-09-18 11:34:13