Sočasna ekstrakcija olja in vodotopnih komponent iz sončničnih semen s subkritično vodo

magistrsko delo študijskega programa II. stopnje

Polona Amon (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Namen magistrskega dela je izvesti ekstrakcijo sončničnih semen z uporabo subkritične vode, ki velja za alternativno in okolju prijazno metodo za sočasno pridobitev olja in vodotopne faze. Prikazana je študija, kako različni parametri ̶ temperatura, tlak, čas in izbrana atmosfera za vzpostavitev tlaka v ekstraktorju vplivajo na izkoristek ekstrakcije obeh faz in vsebnost različnih produktov. Osredotočili smo se na kvalifikacijo in kvantifikacijo produktov hidrotermične degradacije, ki zajemajo olje in vodotopne ekstrakte pri teh pogojih. V oljih smo določili količino totalnih prostih maščobnih kislin s plinsko kromatografijo ter antioksidativnost le-teh s Photochem® metodo ter rezultate primerjali z oljem pridobljenim s konvencionalno Soxhlet metodo, pri čemer se je uporabil n-heksan kot topilo. Vodotopni fazi smo spektrofotometrično določili totalne amino kisline in amine, vsebnost totalnih fenolov in antioksidativno aktivnost. Izvedli smo tudi HPLC analizo za vsebnost klorogenske in kavne kisline ter 5-hidroksimetil furfurala. Rezultati kažejo, da temperatura in čas vplivata na količino in sestavo ekstrakta. Največjo količino olja smo dobili pri temperaturi 190 °C pri ekstrakcijskem času 30 min in uporabljeni atmosferi CO2 za vzpostavitev tlaka v sistemu, ki je znašal 100 bar. Za isti izkoristek smo s konvencionalno metodo potrebovali 2 h, vendar je ekstrakcijski izkoristek na koncu bil bistveno višji. Ugotovili smo, da se vsebnost totalnih maščobnih kislin v olju s povečanjem temperature povečuje, predvsem je to razvidno pri najvišji temperaturi, namreč 240 °C. Prav tako, s povišanjem temperature raste tudi antioksidativna aktivnost olj, ki so dosegla izredno visoke vrednosti v primerjavi z oljem pridobljenim s Soxhletovo metodo. Največja količina vodotopnega ekstrakta je bila pridobljena pri temperaturi 190 °C in ekstrakcijskem času 30 min. Rezultati kažejo visoko količino produktov hidrotermične degradacije. S povečanjem temperature smo zaznali nižje vrednosti antioksidativne aktivnosti vodotopnega ekstrakta.

Keywords

sončnično olje;subkritična voda;ekstrakcija;hidrotermična degradacija;vodotopni ekstrakti;antioksidativna aktivnost;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2015
Typology:	2.09 - Master's Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[P. Amon]
UDC:	[66.061.3:633.494]:665.347.8(043.2)
COBISS:	19412758
Views:	1124
Downloads:	125
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	SIMULTANEOUS EXTRACTION OF OIL AND WATER-SOLUBLE COMPONENTS FROM SUNFLOWER KERNELS WITH SUBCRITICAL WATER
Secondary abstract:	The purpose of the master's thesis was to perform the extraction of sunflower seeds with subcritical water, applicable as an alternative and environmentally friendly method for simultaneous extraction of oil and water-soluble phase. In the study presented, influence of different process parameters - temperature, pressure, time and chosen atmosphere for maintaining the pressure in the extractor on the extraction yield of both phases and presence of different components have been observed. We focused on quantification and qualification of different products of hydrothermal degradation of oil and water-soluble extracts at these conditions. In the oil, the amount of total free fatty acids was determined with gas chromatography. The antioxidant capacity of oil was determined with the Photochem® method. All obtained oils were compared with oil extracted with the conventional Soxhlet extraction method where n-hexane was used as solvent. For determination of total amino acids and amines, antioxidant capacity and content of phenols in water soluble phase spectrophotometric methods were used. The HPLC analysis of some phenolic compounds (5-hydroxymethylfurufral, chlorogenic acid and caffeic acid) was performed. The results indicate that the quantity of the extract was affected by temperature and extraction time. The highest amount of oil was obtained at a temperature of 190 °C, extraction time of 30 min using a CO2 atmosphere at 100 bar. We needed 2 h to get the same yield with the conventional extraction. The amount of total free fatty acids increases with increasing temperature and is highest at the highest temperature, namely 240 °C. With increasing temperature also the antioxidant capacity of oil rises, and reaches extremely high values in comparison with the oil extracted with convencional Soxhlet method. The highest quantity of water soluble extract was obtained at temperature 190 °C and extraction time of 30 minutes. The results show high degree of hydrothermal degradation, since many products have formed. With increasing temperature lower antioxidant capacity of water soluble extract could be observed.
Secondary keywords:	extraciton;oils;sunflower oil;subcritical water;hydrothermal degradation;antioxidant capacity;
URN:	URN:SI:UM:
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 74 str.
ID:	8888604