Ekstrakcija antioksidativnih komponent iz kurkume (curcuma longa)

diplomsko delo univerzitetnega študijskega programa

Teja Boček (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Primerjali smo učinkovitost superkritične in konvencionalne metode ekstrakcije antioksidativnih komponent iz kurkume (Curcuma longa). Superkritično ekstrakcijo smo izvajali s pomočjo laboratorijske visokotlačne ekstrakcijske naprave, kjer smo s črpalko črpali ogljikov dioksid iz jeklenke v avtoklav skozi material pri različnih pogojih tlaka in temperature. Konvencionalne ekstrakcije smo opravljali po naslednjih metodah: ekstrakcija s topili pri povišani tlakih, ekstrakcija po Soxhletu, ekstrakcija s hladnim topilom v bučki in ekstrakcija z ultrazvokom. Kot topilo smo uporabljali absolutni etanol pri vseh metodah konvencionalne ekstrakcije, medtem ko smo topilo heksan uporabljali pri ekstrakciji po Soxhletu in pri ekstrakciji s hladnim topilom v bučki. Dobljene ekstrakte smo shranjevali v zamrzovalniku, zaradi občutljivosti na svetlobo. V dobljenih ekstraktih smo določali vsebnost antioksidativnih komponent. Izkoristki superkritične ekstrakcije so bili približno enaki pri vseh delovnih pogojih. Kot smo lahko videli, pri superkritični ekstrakciji z ogljikovim dioksidom na topnost topljenca minimalno vplivata tlak in temperatura, saj smo pri najvišjem tlaku in temperaturi dobili največji izkoristek. Pri konvencionalni ekstrakciji po Soxhletu in pri ekstrakciji s hladnim topilom v bučki je bilo olje bolj topno v heksanu, ki je nepolarno topilo kot v etanolu. Antioksidativne komponente smo določali po naslednjih metodah: z radikalsko metodo – DPPH, z določitvijo v lipidih topnih antioksidativnih komponent s Photochemom, z beta-karotensko metodo in z metodo celokupnih fenolov. Ugotovili smo, da imajo najmanj antioksidativnih komponent ekstrakti pridobljeni s topilom heksan. Določali smo tudi prisotnost določenih kurkuminoidov v ekstraktih s tankoplastno kromatografijo. Videli smo, da v ekstraktih pridobljenih s heksanom ni bilo prisotnih kurkuminoidov. Določali smo tudi antimikrobno aktivnost na bakteriji Bacillus cereus in Escherichia coli. Ugotovljeno je bilo, da povzročijo največjo inhibicijo rasti ekstrakti pridobljeni s topilom etanol pri povišanih tlakih.

Keywords

superkritična ekstrakcija;konvencionalna ekstrakcija;Curcuma longa;kurkuminoidi;superkritični fluidi;tankoplastna kromatografija;antioksidativna aktivnost;antimikrobna aktivnost;

Data

Language:	Slovenian
Year of publishing:	2013
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[T. Boček]
UDC:	54-139:66.061-987(043.2)
COBISS:	17478422
Views:	2758
Downloads:	272
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	EXTRACTION OF ANTIOXIDATIVE COMPOUNDS FROM CURCUMA (CURCUMA LONGA)
Secondary abstract:	The comparison between supercritical and conventional extraction of antioxidative compounds from Turmeric (Curcuma longa) has been performed. The supercritical extraction was performed with the laboratory high presure extraction device where the carbon dioxide was pumped from the tank to the extractor (through the material) at different conditions of pressure and temperature. The conventional extraction methods used were: extraction with solvents at high presures, Soxhlet extraction, extraction with cold solvents in a flask and extraction with ultrasound. As a solvent absolute ethanol was used in all methods of conventional extraction, while hexane was used in the Soxhlet extraction and extraction with cold solvent in a flask. Due to their sensitivity to sunlight, the obtained extracts were preserved within a freezer. The obtained extracts were analyzed on the content of antioksidative components. The efficiency of the supercritical extractions were very close at all working conditions. Temperature and pressure have minimal impact on the extraction yield; the highest yield was obtained at the highest pressure and highest temperature. With the conventional extraction with Soxhlet and with the cold solvent extraction in a flask the oil was more soluble in hexane which is a non-polar solvent. Antioxidative components were analyzed by following methods: radikal method - DPPH, determination of antioxidative capacity of the lipid soluble compounds (ACL) with Photchem, beta-carotene method and with the method of total fenols. The lowest amount of antioxidative components were extracted with hexane. Furthermore, the presence of curcuminoids in extracts was determined with thin layer cromotagraphy. It was observed that extracts gained with hexane contained no curcuminoids. The antibacterial activites of extracts on the bacteria Bacillus cereus and Escherichia coli were also investigated. The largest growth inhibition was observed for extracts obtained with extraction with absolute ethanol at high presures.
Secondary keywords:	supercritical extraction;conventional extraction;Curcuma longa;kurkuminoids;supercritical fluids;thin layer chromatogaphy;antioxidant activity;antibacterial activity;
URN:	URN:SI:UM:
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	XIII, 79 f.
ID:	8727492