magistrsko delo
Peter Kušar (Author), Blaž Cigić (Reviewer), Tomaž Požrl (Mentor), Tomaž Polak (Co-mentor)

Abstract

V magistrskem delu smo ovrednotili spremembe v spektru fenolnih spojin med procesom priprave ajdovega slada. V poskusu smo uporabili semena dveh sort (pyra in darja) navadne ajde (Fagopyrum esculentum Moench), ki smo jih namakali, kalili, posušili in v različnih fazah procesa odvzemali vzorce za analize vsebnosti vode in fenolnih spojin (nekaljena ajda, 8 ur namočena ajda, kaljena ajda po 16-ih, 40-ih, 64-ih in 88-ih urah, ajdov slad sušen 22 ur pri 60 °C in 18 ur pri 80 °C) Vsebnost vode smo določali s sušenjem, sestavo in vsebnost fenolnih spojin po ekstrakciji z metanolom pa smo določili s tekočinsko kromatografijo z detekcijo na masnem spektrometru (LC-MS). V vzorcih ajde smo določili 12 fenolnih spojin (rutin, orientin, viteksin, izoviteksin, kvercetin, izoorientin, kavno kislino, luteolin, kamferol, naringenin, apigenin in galno kislino). Med kaljenjem se je vsebnost vseh fenolnih spojin v obeh sortah ajde značilno povečala. Najpomembnejša fenolna spojina v nekaljeni ajdi je rutin, ki smo ga tudi v kaljeni ajdi določili največ (pri nekaljeni ajdi v sorti pyra 91,56 μg/g in v sorti darja 103,07 μg/g; pri kaljeni ajdi 88 ur v sorti pyra 355,60 μg/g in v sorti darja 299,95 μg/g). Največje povečanje vsebnosti med kaljenjem smo določili pri orientinu (za faktor 29,2 pri pyri in 21,3 pri darji), viteksinu (za faktor 15,2 pri pyri in 14,0 pri darji) in izoviteksinu (za faktor 17,7 pri pyri in 15,7 pri darji). Pri obeh režimih sušenja se je vsebnost vseh fenolnih spojin v obeh sortah ajde značilno zmanjšala, vendar je bila skupna vsebnost fenolnih spojin v ajdovem sladu še vedno za faktor 2,2 do 3,4 (odvisno od sorte in načina sušenja) večja od skupne vsebnosti fenolnih spojin v nekaljeni ajdi. V ajdi sorte pyra smo po zaključenem kaljenju in sušenju določili nekoliko večjo vsebnost fenolnih spojin kot v ajdi sorte darja. Kaljena ajda in ajdov slad sta dober vir prehransko pomembnih fenolnih spojin.

Keywords

ajda;ajdov slad;zaslajevanje;kaljenje;fenolne spojine;polifenoli;rutin;orientin;izoorientin;viteksin;izoviteksin;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [P. Kušar]
UDC: 633.12:631.547.1:663.43:547.56
COBISS: 89230595 Link will open in a new window
Views: 202
Downloads: 27
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Other data

Secondary language: English
Secondary title: Phenolic composition of germinated buckwheat
Secondary abstract: In the master thesis we evaluated the changes in the spectrum of phenolic compounds during the process of buckwheat malting. In the experiment we used the seeds of two varieties (Pyra and Darja) of common buckwheat (Fagopyrum esculentum Moench), which were soaked, germinated and dried. At different stages of the process, samples were taken for the analysis of water content and determination of various phenolic compounds (unmalted buckwheat, buckwheat soaked for 8 hours, germinated buckwheat after 16, 40, 64 and 88 hours, dried buckwheat for 22 hours at 60 °C and 18 hours at 80 °C). Water content was determined by drying and the content of phenolic compounds after extraction with methanol was determined by liquid chromatography with mass spectrometer detection (LC-MS). Twelve phenolic compounds (rutin, orientin, vitexin, isovitexin, quercetin, isoorientin, caffeic acid, luteolin, kaempferol, naringenin, apigenin and gallic acid) were determined in buckwheat samples. During germination, the content of all phenolic compounds increased significantly in both buckwheat cultivars. The most important phenolic compound in buckwheat is rutin, which was also the most abundand in germinated buckwheat (91.56 μg/g in unmalted buckwheat in Pyra cultivar and 103.07 μg/g in Darja cultivar; in 88 hours germinated buckwheat in Pyra cultivar 355.60 μg/g and 299.95 μg/g in Darja cultivar). The greatest increase in content during germination was found for orientin (factor 29.2 in Pyra and 21.3 in Darja), vitexin (factor 15.2 in Pyra and 14.0 in Darja) and isovitexin (factor 17.7 in Pyra and 15.7 in Darja). Under both drying regimes, the content of all phenolic compounds in both buckwheat cultivars decreased significantly, but the sum of phenolic compound content in the buckwheat malt was still a factor 2.2 to 3.4 (depending on cultivar and drying regime) higher than the sum of phenolic compound content in the unmalted buckwheat. After germination and drying, the buckwheat cultivar Pyra was found to have a slightly higher content of phenolic compounds than the buckwheat cultivar Darja. Germinated buckwheat and buckwheat malt are good sources of nutritionally important phenolic compounds.
Secondary keywords: buckwheat;buckwheat malt;malting;sprouting;phenolic compounds;polyphenols;rutin;orientin;isoorientin;vitexin;isovitexin;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: X, 73 f.
ID: 14101854