Određivanje antioksidacijskih svojstava ekstrakata melise

undergraduate thesis

• Title (english): Determination of antioxidant properties of melissa extracts
• Author: Katarina Marević
• Mentor: Mojca Čakić Semenčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Physical Chemistry and Corrosion); Zagreb
• Defense date and country: 2024-06-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovoga rada bio je ispitati antioksidativnu aktivnost ekstrakata biljke Melissa officinalis L. dobivenih mikrovalnom ekstrakcijom. Ekstrakcije su provedene s demineraliziranom vodom te 30%, 70% i 96%-tnom vodenom otopinom etanola pri temperaturama od 40 °C, 60 °C i 80 °C i vremenu trajanja od 5 i 10 minuta. Antioksidativna aktivnost uzoraka određena je DPPH i FRAP metodom, primjenom UV/Vis spektroskopije. Prema nalazu DPPH analize najviši antioksidativni potencijal, pri svim temperaturama, pokazuju 70%-tni etanolni ekstrakti dok se rezultati FRAP analize razlikuju pri različitim temperaturama. Pri 40 °C najveću aktivnost pokazuju 30%-tni etanolni, pri 60 °C 70%-tni etanolni ekstrakti, a pri 80 °C vodeni ekstrakti. Vrijeme trajanja tretmana je utjecalo na antioksidativnu aktivnost i pritom su veće razlike u rezultatima zamijećene u FRAP analizi. Zaključno, na antioksidativnu aktivnost ekstrakata biljke Melisse officinalis L. utječu temperatura i vrijeme ekstrakcije te otapalo koje se koristi za ekstrakciju.

Abstract (english)

The aim of this study was to investigate the antioxidant activity of Melissa officinalis L. plant extracts obtained through microwave extraction. Extractions were carried out using demineralized water and 30%, 70%, and 96% aqueous ethanol solutions at temperatures of 40 °C, 60 °C, and 80 °C, with extraction times of 5 and 10 minutes. The antioxidant activity of the samples was assessed using the DPPH and FRAP methods with UV/Vis spectroscopy. According to the DPPH analysis results, the 70% ethanol extracts exhibited the highest antioxidant potential across all temperatures. In contrast, the FRAP analysis results varied with temperature: at 40 °C, the 30% ethanol extracts showed the highest activity; at 60 °C, the 70% ethanol extracts were the most active; and at 80 °C, the water extracts demonstrated the highest activity. The extraction duration influenced antioxidant activity, with more significant differences observed in the FRAP analysis results.In conclusion, the antioxidant activity of Melissa officinalis L. extracts is influenced by the temperature and duration of extraction, as well as the type of solvent used.

• Keywords: antioksidativna aktivnost; DPPH metoda; FRAP metoda; mikrovalna ekstrakcija; Melissa officinalis L
• Keywords (english): antioxidant activity; DPPH method; FRAP method; microwave extraction; Melissa officinalis L.
• Language: croatian
• URN:NBN: urn:nbn:hr:159:965649
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-11-12 10:44:30