diplomsko delo univerzitetnega študijskega programa I. stopnje
Jožica Ulčnik (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Namen tega diplomskega dela je bilo napraviti študijo vsebnosti totalnih fenolnih spojin, totalnih flavonoidov in antioksidativne aktivnosti v vodotopnih ekstraktih ostankov semen industrijske konoplje, sezama, lana in sončnice po odstranitvi olja. Kot izhodni material smo uporabili ostanke teh semen po konvencionalni ekstrakcij z mešanjem v heksanu ter po ekstrakciji s superkritičnim ogljikovim dioksidom in tekočim propanom pri dveh različnih ekstrakcijskih pogojih. Ostanke semen po konvencionalni ekstraciji s heksanom smo najprej ponovno estrahirali z istim postopkom, le da smo namesto heksana uporabljali različna razmerja mešanice aceton:voda. Na podlagi najboljšega izkoristka smo kot najidealnejše topilo določili mešanico acetona z vodo v razmerju 30:70. Enako sestavo topila smo nato v nadaljevanju uporabili za ekstrakcije ostankov semen po superkritičnih ekstrakcijah. Vsebnost totalnih fenolnih spojin v vodotopnih ekstraktih smo določili UV spektrofotometrično, po metodi Folin-Ciocalteu-a. Rezultati kažejo nizko vsebnost totalnih fenolov v semenih industrijske konoplje (od 0,29 do 0,46 mg na g materiala) in lana (od 0,24 od 0,64 mg fenolnih spojin na g materiala). Pri sezamu so omenjene spojine prisotne le v sledovih (0,1 do 0,14 mg fenolnih spojin na g materiala). Izmed vseh uporabljenih semen so najvišjo vsebnost fenolnih spojin pokazala sončnična semena (od 1,96 do 3,49 mg fenolnih spojin na g materiala). Vsebnost totalnih flavonoidov smo določili s kolorimetrično metodo z uporabo aluminijevega klorida. Rezultati so pokazali prav tako nizko prisotnost flavonoidov v semenih. Pri lanu in sezamu so dobljene vrednosti celo enake nič. Nekaj višje vrednosti smo dobili pri konoplji (manj kot 0,0420 mg flavonoidov na gram materiala) in sončnici (manj kot 0,67 mg na g materiala). Antioksidativne aktivnosti ekstraktov smo izmerili s spektrofotometrično radikalsko metodo z DPPH in s foto-luminiscenčno (Photochem) metodo. Izkazalo se je, da imajo ekstrakti predhodno razmaščenih semen antioksidativne lastnosti. Najvišjo antioksidatvno aktivnost smo določili v sončničnih semenih (63,7% inhibicija), najnižjo pa pri semenih sezama, kjer inhibicije sploh nismo dosegli.

Keywords

sezam;lan;sončnica;industrijska konoplja;ekstrakcija;fenolne spojine;flavonoidi;antiksidativna aktivnost;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [J. Ulčnik]
UDC: 547.9:633.85(043.2)
COBISS: 17478166 Link will open in a new window
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Other data

Secondary language: English
Secondary title: SEPARATION OF PHENOLIC COMPOUNDS FROM VARIOUS SEEDS AND ANTIOXIDANT PROPERTIES OF EXTRACT
Secondary abstract: The purpose of this thesis was to conduct a study about the total phenolics and total flavonoids content and the antioxidant activities in water-soluble extracts of seed residues of hemp, sesame, flax and sunflower after defattisation. As the basic material, residues of these seeds, after the conventional extraction with mixing in hexane, and after extraction with supercritical carbon dioxide and propane at two different extraction conditions were used. The seed residues produced by conventional extraction with hexane were reextracted using conventional extraction with mixing and different ratios of aceton:water. Based on the highest obtained yield of the most suitable solvent mixture was determined with a ratio of aceton:water = 30:70. The same composition of the solvent was used for extractionof defatted seeds by supercritical extractions. The content of total phenolic compounds in water-soluble extracts was determined by UV spectrofotometry, using the Folin-Ciocalteu method. The results indicate a low content of total phenols in hempseed (from 0.29 to 0.46 mg phenolic compounds per gram of material) and flaxseed (from 0.24 to 0.64 mg phenolic compounds per gram of material). The mentioned compounds appear only in traces in sesame seeds (from 0.1 to 0.14 mg per gram of material). Among the seeds used, the highest content of phenolic compounds was found in sunflower seeds (from 1.96 to 3.49 mg per gram of material). The content of total flavonids was determined by the colorimetric method using aluminium chloride. The results have shown that there is a low content of flavonoids in the deffated seeds. The content of flavonoids was equal to zero in flax and sesame seeds. Higher amounts were found in hempseed (less than 0.0420 mg per gram of material) and sunflower seeds (less than 0.67 mg per gram of material). Antioxidant properties of the water-soluble extracts were measured by the spectrofotometric radical scavenging method with DPPH and by photo-luminescent (Photochem) method. The results have indicated that defatted seed extracts have antioxidant properties. The highest antioxidant activity was found in sunflower seeds (the degree of inhibition reached 63.7 %), and the lowest was found in sesame seeds, where no inhibition was measured.
Secondary keywords: sesame;flax;sunflower;industrial hemp;extraction;phenolic compounds;flavonoids;antioxidant activity;
URN: URN:SI:UM:
Type (COBISS): Bachelor thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: X, 45 f.
ID: 8727585