Izolacija bioaktivnih spojeva ploda pasjeg trna primjenom ekstrakcije potpomognute mikrovalovima

master's thesis

• Title (english): Isolation of bioactive compounds from sea buckthorn fruit using microwave assisted extraction
• Author: Viktorija Rnjak
• Mentor: Ivona Elez Garofulić (mentor)
• Committee member: Verica Dragović-Uzelac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2021-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je optimirati parametre ekstrakcije potpomognute mikrovalovima (MAE) za izolaciju fenolnih spojeva i biljnih pigmenata iz ploda pasjeg trna (Hippophae rhamnoides L.) Ekstrakcija je provedena uz pomoć 70 %-tnog etanola kao otapala i pritom je ispitan utjecaj temperature (40, 60 i 80°C), snage mikrovalova (300, 500 i 700 W) i vremena ekstrakcije (5, 10 i 15 min) na masene udjele izoliranih spojeva. Maseni udjeli bioaktivnih spojeva određeni su spektrofotometrijski s prosječnim vrijednostima: ukupni fenoli (322,87 mg GAE 100 gˉ¹), klorofil a (2,53 mg 100 gˉ¹), klorofil b (6,27 mg 100 gˉ¹) i ukupni klorofili (8,80 mg 100 gˉ¹). Također, određena je antioksidacijska aktivnost FRAP metodom s prosječnom vrijednošću 2011,42 μmol TE 100 gˉ¹. Statističkom analizom utvrđeno je kako sva tri varirana parametra imaju statistički značajan (p ≤ 0,05) utjecaj na masene udjele bioaktivnih spojeva dok parametar snage jedini ima statistički značajan (p ≤ 0,05) utjecaj na vrijednosti antioksidacijske aktivnosti. Najveći prinos ukupnih fenola određen je u ekstraktu dobivenom pri 80°C/300 W/10 min, ukupnih klorofila u ekstraktu dobivenom pri 80°C/300 W/5min, dok je najviša antioksidacijska aktivnost određena u ekstraktu dobivenom pri 80°C/500 W/10 min.

Abstract (english)

The aim of this thesis was to optimize conditions for the isolation of phenolic compounds and plant pigments from sea buckthorn fruit (Hippophae rhamnoides L.) using microwave assisted extraction (MAE). The extraction was performed with a solvent of 70 % ethanol and the influence of temperature (40, 60 and 80°C), microwave power (300, 500 and 700 W) and extraction time (5, 10 and 15 min) on the mass fractions of isolated compounds was examined. Mass fractions of bioactive compounds were determined spectrophotometrically with average values: total phenols (322,87 mg GAE 100 gˉ¹), chlorophyll a (2,53 mg 100 gˉ¹), chlorophyll b (6,27 mg 100 gˉ¹) and total chlorophyll (8,80 mg 100 gˉ¹). In addition, the antioxidant activity was determined by FRAP assay with an average value of 2011,42 μmol TE 100 gˉ¹. Statistical analysis showed that all three varied parameters have a statistically significant (p ≤ 0,05) effect on mass fractions of bioactive compounds, while the power parameter alone has a statistically significant (p ≤ 0,05) effect on antioxidant activity. The highest yield of total phenols was obtained at 80°C/300 W/10 min, total chlorophyll at 80°C/300 W/5min, while the highest antioxidant activity was obtained at 80°C/500 W/10 min.

• Keywords: antioksidacijska aktivnost; biljni pigmenti; MAE; plod pasjeg trna; ukupni fenoli
• Keywords (english): antioxidant activity; MAE; plant pigments; total phenols; sea buckthorn fruit
• Language: croatian
• URN:NBN: urn:nbn:hr:159:112615
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-10-27 09:38:19