diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje
Povzetek
Za izolacijo biološko aktivnih komponent uporabljamo postopek ekstrakcije. Namen je bil ugotoviti kako izbira topila in procesni pogoji vplivajo na kvaliteto oziroma na sestavo ekstrakta pridobljenega iz navadne ajde (Fagopyrum esculentum). Pri eksperimentalnem delu smo uporabili konvencionalne in superkritične metode ekstrakcije. Izvedli pa smo tudi ekstrakcijo polisaharidov. Pridobljenim ekstraktom smo določevali vsebnost prostih ogljikovih hidratov s fenol-žveplovo metodo in vsebnost proteinov z Bradfordovo metodo ter antioksidativno aktivnost ekstraktov z uporabo 2,2-difenil-1-pikrilhidrazil (DPPH*) prostega radikala. Izvedli smo tudi analize LC-MS/MS in določili vsebnost taninov.
Najvišji izkoristek smo pridobili z ekstrakcijo po Soxhletu z uporabo topil petroleter in heksan. Ugotovili smo, da v našem primeru masni izkoristek ekstrakcije ne narašča v smeri rasti polarnosti topil. Razlog je v visoki vsebnosti nepolarnih komponent v semenih navadne ajde. Na izkoristek je vplivala tudi višja temperatura pri ekstrakciji.
Najvišjo vsebnost prostih ogljikovih hidratov smo zasledili pri ekstraktu, kjer smo ekstrahirali polisaharide in pri nepredelanem materialu. Ugotovili smo tudi, da največ proteinov vsebuje ekstrakt, pridobljen s superkritično ekstrakcijo, najmanj pa sam material. Najvišji % inhibiranega DPPH sta vsebovala ekstrakta, kjer smo kot topilo uporabili metanol in metodo po Soxhletu ter ultrazvočno ekstrakcijo. Ugotovili smo, da temperatura ne vpliva bistveno na antioksidativno aktivnost. Izvedli smo analizo taninov v naših vzorcih z LC-MS/MS. Hidrolizirajoči tanini so bili prisotni samo v metanolnih in etanolnih ekstraktih. Od teh smo identificirali le elagno in galno kislino, ki smo ju tudi kvantificirali.
Zaključimo lahko, da je velik delež spojin v ajdi nepolarne narave, ter da njihova topnost narašča z naraščujočo temperaturo. Ajda je kvalitetno živilo s številnimi pozitivnimi učinki na zdravje, saj vsebuje veliko biološko aktivnih snovi, ki smo jih tudi dokazali.
Ključne besede
superkritična ekstrakcija;ektrakcija rastlinskih materialov;biološka aktivnost;organska topila;hidrolizirajoči tanini;diplomske naloge;
Podatki
Jezik: |
Slovenski jezik |
Leto izida: |
2018 |
Tipologija: |
2.11 - Diplomsko delo |
Organizacija: |
UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo |
Založnik: |
[Z. Štukovnik] |
UDK: |
66.061.3(043.2) |
COBISS: |
21950998
|
Št. ogledov: |
1097 |
Št. prenosov: |
167 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Extraction of compounds from the common buckwheat seeds (Fagopyrum esculentum) |
Sekundarni povzetek: |
The extraction process is used for the isolation of biologically active components. The aim was to determine how the solvents and process conditions influenced the quality and composition of the extracts obtained from the common buckwheat (Fagopyrum esculentum). In the experimental work, conventional and supercritical extraction methods were used. We also carried out the extraction of polysaccharides. In the obtained extracts we determined the free carbohydrate content by the phenolic-sulfur method and the protein content by the Bradford method. Antioxidant activity was determined using the free radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH*). We also carried out an analysis of LC-MS/MS in terms of tannin content.
The highest yield was obtained by extraction with Soxhlet using solvent petroleum ether and hexane. In our case the mass yield of the extraction does not increase in the direction of the growth of solvents polarity. The reason is the high content of nonpolar components in common buckwheat seeds. The efficiency was also influenced by the higher temperatures.
The highest content of free carbohydrates was found in the extract, where polysaccharides were extracted and in unprocessed material. The highest content of proteins was found in an extract obtained by supercritical extraction, and the lowest content of proteins was in the material itself. The highest % of the inhibited DPPH contained extracts, where methanol as solvent and Soxhlet method and ultrasonic extraction were used. We found that the temperature does not significantly affect the antioxidant activity. We analyzed the tannins in our samples with LC-MS/MS. Hydrolyzable tannins were present only in methanolic and ethanolic extracts. Of these, only ellagic and gallic acid were identified and quantified.
It can be concluded that a large proportion of the compounds in the common buckwheat are of nonpolar nature and that their solubility increases with increasing temperature. Common buckwheat has many positive effects on health, as it contains many biologically active substances, which we have also proved. |
Sekundarne ključne besede: |
subcritical extraction;Fagopyrum esculentum;extractium from plant materials;biological activity;organic solvents;hxdrolyzable tannins; |
URN: |
URN:SI:UM: |
Vrsta dela (COBISS): |
Diplomsko delo/naloga |
Komentar na gradivo: |
Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo |
Strani: |
X, 39 str. |
ID: |
10949699 |