Phenolic characterization and bioactivity of fennel seed (Foeniculum vulgare Mill.) extracts isolated by microwave-assisted and conventional extraction

Malin, Valentina (author), Elez-Garofulić, Ivona (author), Repajić, Maja (author), Zorić, Zoran (author), Pedisić, Sandra (author), Sterniša, Meta (author), Smole Možina, Sonja (author), Dragović-Uzelac, Verica (author)

The aim of this study was to evaluate the effectiveness of microwave-assisted extraction (MAE) as an environmentally friendly approach compared to conventional heat-reflux extraction (CE) for the isolation of fennel (Foeniculum vulgare Mill.) seed polyphenols and to assess the bioactivity of the obtained extracts. Water, ethanol (30%, v/v) and acetone (30%, v/v) were used as extraction solvents, and the extraction was carried out varying the temperature (40, 60 and 80 °C), irradiation time (5 and 10 min) and microwave power (300 and 600 W). According to the total phenolic content (TPC), 30% acetone at 80 °C after 5 min of irradiation at 300 W proved to be the optimal MAE conditions for obtaining the highest yield of polyphenols. The phenolic profile of both extracts comprised 21 compounds, with cinnamic acids and flavonols being the most abundant. When compared to CE, the MAE extract showed a lower amount of TPC as well as the sum of all identified individual phenols, although both extracts showed similar antioxidant capacity. The antimicrobial activity of the extract with the highest phenolic content was weak, showing inhibitory activity only against Pseudomonas fragi, Shewanella putrefaciens and Campylobacter jejuni strains, while Gram-positive bacteria and yeasts were not sensitive to the extract.

• Language: English
• Keywords: Foeniculum vulgare Mill., fennel seeds, microwave-assisted extraction, heat-reflux extraction, polyphenols, antioxidant capacity, antimicrobial activity, microdilution, UPLC-MS/MS, ORAC
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 16 str.
• Numbering: Vol. 10, iss. 3, art. 510
• PID: 20.500.12556/RUL-137232
• UDC: 579.67:579.24:547.9:66.061
• ISSN on article: 2227-9717
• DOI: 10.3390/pr10030510
• COBISS.SI-ID: 99914499
• Publication date in RUL: 08.06.2022

Record is a part of a journal

• Title: Processes
• Shortened title: Processes
• Publisher: MDPI AG
• ISSN: 2227-9717
• COBISS.SI-ID: 523353113

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 03.03.2022

Secondary language

• Language: Slovenian
• Keywords: koromač, ekstrakcija z mikrovalovi, pospešena ekstrakcija, polifenoli, antioksidativni potencial, protimikrobno delovanje, mikrodilucija