diplomsko delo
Mojca Podgoršek (Author), Tomaž Polak (Reviewer), Rajko Vidrih (Mentor)

Abstract

Namen diplomskega dela je bil na osnovi znanstvenih virov ugotoviti, kako temperatura praženja bučnih semen vpliva na tvorbo policikličnih aromatskih ogljikovodikov (PAH) in posledično na prisotnost le-teh v bučnem olju. S pomočjo literature smo želeli določiti, katera temperatura praženja bučnih semen zagotavlja olje z vsebnostjo PAH znotraj predpisanih mejnih vrednosti in katera temperatura praženja zagotavlja tipično aromo bučnega olja ob čim nižji vsebnosti PAH. Ugotovili smo, kot je bilo pričakovano, da višja kot je temperatura praženja bučnih semen, večja je vsebnost PAH v bučnem olju. Primerjava treh študij je pokazala, da temperatura praženja do 150 °C zagotavlja varno olje z zelo nizko koncentracijo PAH. Praženje bučnih semen pri temperaturi 150 °C povzroči opazno povečanje koncentracije PAH, vendar vsebnosti benzo(a)pirena in skupne vsebnosti štirih PAH (benzo(a)pirena, benzo(a)antracena, benzo(b)fluorantena in krizena) v nobenem primeru niso presegle predpisanih mejnih vrednosti (2,0 μg/kg za benzo(a)piren in 10,0 μg/kg za vsoto štirih PAH). S povišanjem temperature se bistveno spremeni tudi sestava hlapnih spojin (arome). Zaključimo lahko, da praženje bučnih semen pri temperaturi 120 °C daje bučno olje, ki je varno za potrošnika, saj vsebuje zelo nizke koncentracije PAH, hkrati pa zagotavlja značilno in zaželeno aromo bučnega olja po svežem, zelenem, sadnem in hkrati po praženem ter oreških. Koraka praženja torej ni smiselno izpustiti, saj zagotavlja značilne senzorične lastnosti in ob pravilnih pogojih ne vodi v prekomerno tvorbo PAH.

Keywords

bučno olje;bučna semena;policiklični aromatski ogljikovodiki;onesnaževala;praženje;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Podgoršek]
UDC: 664.34:635.62:615.9
COBISS: 4953976 Link will open in a new window
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Downloads: 331
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Other data

Secondary language: English
Secondary title: Influence of roasting temperature of pumpkin seed on the content of polycyclic aromatic hydrocarbons in pumpkin seed oil
Secondary abstract: The aim of this B. Sc. thesis was to determine how the roasting temperature of pumpkin seeds influences the formation of polycyclic aromatic hydrocarbons (PAH) and consequently, the presence of PAH in pumpkin seed oil. We wanted to establish which roasting temperature ensures the oil with PAH content within the prescribed limit values and which roasting temperature provides a typical aroma of pumpkin seed oil with the lowest possible content of PAH. We have determined, as expected, that PAH concentration increases with the increase of the roasting temperature. A comparison of three studies has shown that a roasting temperature up to 150 °C provides a safe oil with a very low PAH concentration. The roasting of pumpkin seeds at 150 °C results in a noticeable increase in the PAH concentration, however the content of benzo(a)pyrene and the total content of four PAHs (benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene) do not exceed the prescribed limit values (2.0 μg/kg for benzo(a)pyrene and 10.0 μg/kg for the sum of four PAHs) in any of the samples. The composition of volatile compounds also changes significantly with increase of roasting temperature. We can therefore conclude that the roasting of pumpkin seeds at 120 °C gives an oil which is safe for the consumer, because it contains very low PAH concentration and at the same time provides a characteristic and desirable fresh, green, fruity, and also roasted, nutty aroma of pumpkin seed oil. It is not useful to omit the roasting step because it is necessary for the characteristic sensory properties and does not lead to excessive PAH formation.
Secondary keywords: pumpkin seed oil;pumpkin seeds;polycyclic aromatic hydrocarbons;contaminants;roasting;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 23 f.
ID: 10959657