Optimization of extraction and quantification technique for phenolics content of garlic (Allium sativum): An application for comparative phytochemical evaluation based on cultivar origin

Abstract

A range of conventional, i.e. maceration, percolation, ultrasonic assisted, Soxhlet and Soxtec extraction (STE), to advanced extraction techniques of accelerated solvent extraction (ASE) was utilized for the first time in order to optimize the extract yield and recovery of phenolics-gallic acid (GA), rutin (RT) and quercetin (QT)-quantified via ultra-high performance liquid chromatography with diode array detector (UHPLC-DAD). The effect of solvents (n-hexane, dichloromethane and methanol) and temperature (60, 80 and 100 C) upon extraction yield, phenolic content and antioxidant activity (DPPH, ABTS and DPPH) was studied, and the method was validated in commercial food samples from Saudi Arabia, China and India. A high extract yield with percentage recovery was observed for STE (1221.10 mg/5 g; 24.42%) and ASE techniques (91.50 mg/1 g; 9.15%) in methanol at 100 C. UHPLC-DAD showed retention times (min) of 0.67, 1.93 and 1.90 for GA, RT and QT, respectively in the shortest runtime of 3 min. The yield for phenolics was higher for STE/ASE (ppm): 15.27/15.29 (GA), 85.24/37.56 (RT) and 52.20/33.40 (QT), respectively. In terms of antioxidant activities, low IC 50 values (μg/ml) of 1.09/1.18 (DPPH), 2.11/5.32 (ABTS) and 4.35/7.88 (phenazine methosulfate-nicotinamide adenine dinucleotide) were observed for STE and ASE, respectively. Multivariate analysis for STE showed a significant (P = 0.000) correlation for extraction type vs. extract yield and phenolics content; however, there was no significance for antioxidant activities vs. extraction type. ASE showed a positive correlation for solvent vs. extraction yield, phenolics and antioxidant activity; however, there was no correlation for extraction yield and DPPH activity. Principal component analysis for STE showed a major variability (52.02%) for extraction yield and phenolics in PC1 followed by PC2 (38.30%) for antioxidant activities. For ASE, PC1 (48.68%) showed a positive correlation for solvent vs. extraction yield and phenolics while PC2 (33.12%) showed a positive correlation for temperature and antioxidant activities. STE and ASE were the optimized extraction techniques for the garlic food sample while a significant effect of solvent and temperature was observed upon extraction yield, phenolics and antioxidant activity.

Methods of Isolation of Active Substances from Garlic (Allium sativum L.) and Its Impact on the Composition and Biological Properties of Garlic Extracts

“…Antioxidant activity depends on the position of phenol hydroxyl groups, and phenolic compounds with lower molecular weights exhibit their greater bioavailability [ 28 ]. The study of Ahmad et al [ 125 ] assessed the effect of methods, i.e., maceration, percolation, ultrasonic-assisted, Soxhlet and Soxtec extraction (STE), and accelerated solvent extraction (ASE), on the extract yield and phenolic content of Allium sativum L. In addition to the above, the effect of the type of solvents such as n-hexane, dichloromethane and methanol, and temperature (60, 80, and 100 °C) on the following factors such as extraction yield was evaluated, phenolic content and antioxidant activity (DPPH, and ABTS). Both STE and ASE methods using methanol as solvent at 100 °C showed high yield and recovery of the extract equal to 1221.10 mg/5 g (24.42%) and 91.50 mg/1 g (9.15%), respectively [ 125 ].…”

“…A positive correlation was found between the type of extraction, the yield of the extract, and the content of phenolic compounds, which was not the case between the antioxidant activity and the type of extraction for the STE method [ 125 ]. In the case of the ASE method, there was a positive correlation between the solvent and the extraction efficiency, phenols, and antioxidant activity, and no correlation was found between the extraction efficiency and DPPH activity.…”

“…In the case of the ASE method, there was a positive correlation between the solvent and the extraction efficiency, phenols, and antioxidant activity, and no correlation was found between the extraction efficiency and DPPH activity. In addition, for both STE and ASE, low IC 50 values (μg/mL) were found at 1.09 and 1.18 for DPPH, 2.11 and 5.32 for ABTS, and 4.35 and 7.88 for phenazine methosulfate-nicotinamide adenine dinucleotide [ 125 ].…”

Extraction and Analysis of Chemical Compositions of Natural Products and Plants

“…Wilson et al [21] extracted total cannabidiol from cannabis by both maceration and percolation, respectively, and the results showed that percolation was more efficient than maceration extraction. In another study on the extraction of phenolics from Allium sativum, extraction and recovery rates were higher with percolation than with maceration [22]. Similarly, in a comparison of the extraction of volatile components from grapeseed oil, Soxhlet extraction yielded 67 volatile components, while percolation yielded 60 volatile components [23].…”

Approaches, Strategies and Procedures for Identifying Anti-Inflammatory Drug Lead Molecules from Natural Products

“…In general, factors such as powder size, solvent composition, extraction time, percolation flow rate, and solvent amount determine the efficacy of extraction [ 102 , 103 ]. In a study on phenolic extraction from Allium sativum L., percolation exhibited higher extraction and recovery rates than maceration [ 104 ]. Similarly, comparing volatile component extraction from grapeseed oil, percolation yielded 60 components, whereas Soxhlet extraction produced 67 [ 105 ].…”