magistrsko delo
Kaira Recko (Author), Helena Abramovič (Reviewer), Mojca Korošec (Mentor), Iztok Prislan (Co-mentor)

Abstract

Namen dela je bil ugotoviti povezavo med fizikalno-kemijskimi lastnostmi medu, sladkornih sirupov in mešanic medu in sirupov. Želeli smo ugotoviti, kako se lastnosti spreminjajo v odvisnosti od deleža dodanega sirupa in vrste sirupa (glukozno-fruktozni in rižev sirup) na primeru treh vrst medu, to je akacijevega, cvetličnega in kostanjevega. Med je živilo, ki se uvršča med pogosteje potvorjena živila. Zaradi številnih nepoštenih praks pridelave medu smo želeli dobiti vpogled, katera metoda, poleg standardnih za preverjanje pristnosti, bi najhitreje pokazala morebitno potvorbo medu. Rezultati so pokazali, da se fizikalno-kemijske lastnosti spreminjajo glede na botanično poreklo medu in glede na delež in vrsto dodanega sirupa v med. Pri DSC analizi smo ugotovili, da se temperatura steklastega prehoda manjša z dodajanjem sirupa in večanjem njegovega deleža. Pri vsebnosti vode smo ugotovili, da le-ta narašča z večanjem vsebnosti sirupa, prav tako se veča tudi pH vrednost. Vrednosti električne prevodnosti z večanjem deleža sirupa padajo. Ugotovili smo tudi, da se vsebnosti prostih kislin manjšajo z dodajanjem sirupa in da se vsebnost laktonov povečuje z dodajanjem sirupa. Dodajanje sirupa igra pomembno vlogo tudi pri barvi medu, saj se vrednosti parametra L* povečujejo, parametra a* zmanjšujejo, pri parametru b* pa se pri akacijevem in cvetličnem medu zmanjšujejo, medtem ko se pri kostanjevem povečujejo.

Keywords

med;akacijev med;cvetlični med;kostanjev med;fizikalno-kemijske lastnosti;vsebnost vode;električna prevodnost;kislost;barva;diferenčna dinamična kalorimetrija;senzorične lastnosti;pristnost medu;metode preverjanja pristnosti medu;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Recko]
UDC: 638.16:543.2/.9
COBISS: 109153283 Link will open in a new window
Views: 96
Downloads: 17
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: Determination of physico-chemical properties of models of different honey types, syrups and their mixtures
Secondary abstract: The aim of this thesis was to establish a correlation between different physicochemical properties of honey, sugar syrups, as well as honey and syrup mixtures. For that purpose, it was analysed how these properties vary across three different honey types, namely acacia, polyfloral and chestnut honeys, depending on their sugar syrup concentration or syrup type added (such as a glucose-fructose or rice syrup). Honey is classified among ten most often adulterated food products. Given numerous unfair practices occurring in the honey production, the thesis explored which alternative method would be the most feasible and robust one to detect any potential honey adulteration. The results obtained have shown that the physicochemical properties largely depend on the botanical origin of honey, as well as on the concentration and type of the syrup added. The DSC analysis demonstrated that the glass transition temperature decreases as the concentration of the syrup added increases. The water content in honey has been found to rise with the increase of syrup content. Similarly, as the syrup concentration increases the pH values observed rise, and those of the electrical conductivity diminish. It was also noticed that with the addition of syrup to honey, free acidity is reduced, and lactone content increased. The increase of syrup concentration also plays an important role in the colour of honey, with the L* parameter values increasing, and the a* parameter decreasing, or - in the case of the b* parameter - the values decreasing for both acacia and floral honeys, while increasing for chestnut honey.
Secondary keywords: honey;acacia honey;flower honey;chestnut honey;physicochemical properties;water content;electrical conductivity;acidity;color;differential dynamic calorimetry;sensory properties;authenticity of honey;analytical methods for honey authenticity;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 60 f.
ID: 15427809