Effect of accelerated solvent extraction conditions on the isolation of bioactive compounds from fennel (Foeniculum vulgare Mill.) seeds

Abstract

This study focused to establish the optimal conditions of accelerated solvent extraction (ASE), i.e., temperature, static extraction time and number of extraction cycles, for the isolation of fennel (Foeniculum vulgare Mill.) seeds phenols and pigments using 96% ethanol as an extraction solvent. Hence, extraction conditions of temperature (80 and 110 °C), static extraction time (5 and 10 min) and number of extraction cycle (1, 2, 3 and 4) were varied. Obtained extracts were spectrophotometrically analyzed for the content of total phenols (TP), total chlorophylls (TCHL) and total carotenoids (TCAR). Applied extraction conditions had a significant (p<0.01) influence on the yields of analyzed compounds, except for static extraction time on TCAR (p=0.11). Based on the results of statistical analysis, the highest levels of TP and TCHL were achieved at the most invasive conditions (110 °C/10 min/4 cycles), while shorter period was sufficient to reach the highest TCAR yield (110 °C/5 min/3 cycles). In summary, ASE demonstrated to be effective extraction technique for the isolation of fennel seeds hydrophilic and lipophilic bioactive compounds.

Phenolic Characterization and Bioactivity of Fennel Seed (Foeniculum vulgare Mill.) Extracts Isolated by Microwave-Assisted and Conventional Extraction

“…TPC of MAE extracts ranged from 237.3 ± 10.5 to 706.2 ± 19.0 mg GAE/100 g, which is in agreement with the results of Roby et al (2013) [32], where maceration during 72 h was applied. Repajić et al (2020) [33] reported lower TPC values (145.27-474.21 mg GAE/100 g) for the extractions performed with pressurized liquid extraction. Higher TPC was reported in methanolic and ethanolic fennel seed extracts from Pakistan (627.21 ± 18.36-967.50 ± 35.51 mg GAE/100 g) [34] and in methanolic extracts from Iran and Europe (14 ± 0.18-262 ± 0.91 mg/g of dry weight (dw) [35], both isolated by maceration during 8 and 24 h, respectively.…”

Critical Review on Nutritional, Bioactive, and Medicinal Potential of Spices and Herbs and Their Application in Food Fortification and Nanotechnology

“…Seeds contain several lipophilic and hydrophilic compounds like carotenoids, phenols, chlorophylls, unsaturated fatty acids, and phytosterols. These compounds act as potential antioxidant agent and prevent various types of diseases [ 760 ]. The major phytoconstituents of fennel seeds are volatile aroma compounds, phenols, and phenolic glycosides like trans-anethole (81.63% and 87.85%), fenchone, and estragole.…”

Comparison of Conventional and Green Extraction Techniques for the Isolation of Phenolic Antioxidants from Sea Fennel

“…Studies have shown that water content increases the extraction efficiency of polyphenolics, because the contact area between the substance and the solvent increases due to the swelling effect of water on plant tissue [15]. Recently, scientists have also investigated the application of unconventional extraction techniques such as microwave-assisted extraction (MAE) [16][17][18], ultrasound-assisted extraction (UAE) [19,20], pressure-assisted liquid extraction (PLE) [21,22], supercritical CO 2 extraction (SC-CO 2 ) [23,24], pulsed electric field (PEF)-assisted extraction [25,26], and enzyme-assisted extraction (EAE) [27][28][29] compared to conventional solvent extraction (CSE) methods, such as Soxhlet extraction, decoction, maceration, infusion, percolation, digestion, serial exhaustive extraction, and simple mixing, due to their numerous advantages [13]. These new techniques are considered to be environmentally friendly extraction methods and are therefore suitable for application.…”