| Abstract: | ![]()
Flixweed (Descurainia sophia) seeds (FS) is a rich source of polyphenols. This study aimed to investigate the effects of various solvents (water, aqueous-methanol and aqueous-ethanol) and techniques (maceration (M), ultrasound-assisted extraction (UAE), ohmic-assisted extraction (OAE), and decoction – infusion (DI)) on extraction yield, pH, total phenolic contents (TPC), and antioxidant activity (DPPH radical scavenging activity (DRSA)) of flixweed seeds powder (FSP). Extraction systems were ranked by fuzzy-logic (inputs: extraction yield and time, TPC and DRSA). Water as a solvent in extraction process had the maximum yield, TPC and DRSA 6.49%; 141.598 mg GAE/100 mL and 72.91%, respectively. The difference between water and aqueous-ethanol was significant (p < 0.05). Values of pH of aqueous-methanol extract was significantly higher than other solvents. OAE and UAE achieved the highest (10.1%) and lowest (2.3%) extraction yields, respectively. Low temperature maceration showed the highest TPC and DRSA. Fuzzy-logic ranking based on expert's knowledge (30 experts) predicted the OAE with water as solvent to be score the highest rank in terms of overall efficiency. The overall efficiency is determined based on yield, extraction duration, antioxidant activity, and TPC. However, if the ranking are to be based on isolation of bioactive materials at a reasonably short time, the UAE may be the preferred choice. The HPLC analysis of OAE water extract indicates the presence of several phenolic compounds such as caffeic acid, p-coumaric acid, rutin, quercetin, and kaempferol. |
