Izolacija fenolnih spojeva iz lista borovnice primjenom ekstrakcije potpomognute mikrovalovima (MAE)

master's thesis

• Title (english): Isolation of phenolic compounds from blueberry leaves using microwave-assisted extraction (MAE)
• Author: Katja Martinović
• Mentor: Verica Dragović Uzelac (mentor)
• Mentor: Ana Dobrinčić (pomoć pri izradi, neposredni voditelj)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for drying Technologies and monitoring of biologically active compounds); Zagreb
• Defense date and country: 2023-09-14, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Listovi borovnice (Vaccinium myrtillus) su nusprodukt berbe i prerade plodova te se uglavnom smatraju otpadom. Međutim bogat su izvor fenolnih spojeva koji posjeduju brojna biološka djelovanja, poput antioksidacijske ili antimikrobne. U ovome radu ekstrahirani su fenolni spojevi iz listovima borovnice primjenom napredne ekstrakcijske tehnike potpomognute mikrovalovima (MAE). Ekstrakcija je provedena uz 30 %-tni etanol kao otapalo te se pratio utjecaj temperature, vremena i omjera uzorka i otapala na koncentraciju fenolnih spojeva. Kvantitativno određivanje ukupnog sadržaja fenolnih spojeva u listovima borovnice određen je spektrofotometrijski Folin-Ciocalteu metodom pri valnoj duljini od 765 nm. Prosječna količina ukupnih fenola iznosila je 44,78 ± 9,73 mg GAE g⁻¹, a porastom temperature sa 60 na 80 °C koncentracija fenolnih spjeva porasla je sa 40,43 na 52,24 mg GAE g⁻¹ . Vrijeme ekstrakcije nije statistički značajno utjecalo na koncentraciju ukupnih fenola, stoga se vrijeme od 5 minuta smatra optimalnim. Veći omjer otapala u odnosu na uzorak (40 mL g⁻¹) rezultirao je većom koncentracijom ekstrahiranih fenola (52,24 ± 0,46 mg GAE g⁻¹ ).

Abstract (english)

Blueberry (Vaccinium myrtillus) leaves are a by-product of fruit harvesting and processing and are generally considered as waste. However, they are a rich source of phenolic compounds that possess numerous biological activities, such as antioxidant or antimicrobial. In this work, phenolic compounds were extracted from blueberry leaves using an advanced microwave-assisted extraction (MAE) technique. The extraction was carried out with 30% ethanol as a solvent, and the influence of tempera ture, time and ratio of sample to solvent on the concentration of phenolic compounds was monitored. Quantitative determination of the total phenolic compounds content in blueberry leaves was determined spectrophotometrically by the Folin-Ciocalteu method at a wavelength of 765 nm. The average amount of total phenols was 44.78 ± 9.73 mg GAE g⁻¹ , and as the temperature increased from 60 to 80 °C, the concentration of phenolic compounds increased from 40.43 to 52.24 mg GAE g⁻¹ . The extraction time did not have a statistically significant effect on the concentration of total phenols, therefore a time of 5 minutes was considered optimal. A higher ratio of solvent to sample (40 mL g⁻¹ ) resulted in a higher concentration of extracted phenols (52.24 ± 0.46 mg GAE g⁻¹ ).

• Keywords: list borovnice; fenoli; ekstrakcija; ekstrakcija potpomognuta mikrovalovima
• Keywords (english): blueberry leaf; phenols; extraction; microwave-assisted extraction
• Language: croatian
• URN:NBN: urn:nbn:hr:159:286205
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-06-28 08:51:29