Phenolic Profile and Antioxidant Capacity of Walnut Extract as Influenced by the Extraction Method and Solvent

Author(s):  
Ion Trandafir ◽  
Sina Cosmulescu ◽  
Violeta Nour

Abstract Total phenolic content, total flavonoid content, antioxidant activity and individual phenolic compounds were assessed in full fat and defatted walnut kernel. For quantification of phenolic fraction of walnut kernels, two different solvents (methanol and ethanol) and two methods of extraction (ultrasonic-assisted extraction and Soxhlet extraction) were tested. Total phenolics, flavonoid content and antioxidant capacity of alcoholic extracts varied depending on the solvent used and extraction methods. Seventeen phenolic compounds were detected and the study provides evidence on high phenolic contents and high antioxidant potential of full fat walnut kernel and defatted walnut kernel. The Soxhlet extraction is the best in terms of the amounts of total phenolic content (2,089.2 mg gallic acid equivalent/100 g dry matter), while the ultrasonic assisted extraction is a fast method but resulted in significantly lower phenolic content (667.3–1,426.8 mg gallic acid equivalent /100 g dry matter). The concentrations of phenolics (especially (+)-catechin hydrate, juglone, vanillic acid, caffeic acid, ferulic acid, sinapic acid, salicylic acid and ellagic acid) are many fold lower in ultrasonic-assisted extraction as compare to the Soxhlet method using the same extraction solvent. The results of this study provide evidence on high phenolic contents and high antioxidant potential of full fat and defatted walnut kernel.

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 582
Author(s):  
Inês Mansinhos ◽  
Sandra Gonçalves ◽  
Raquel Rodríguez-Solana ◽  
José Luis Ordóñez-Díaz ◽  
José Manuel Moreno-Rojas ◽  
...  

The present study aimed at evaluating the effectiveness of different natural deep eutectic solvents (NADES) on the extraction of phenolic compounds from Lavandula pedunculata subsp. lusitanica (Chaytor) Franco, on the antioxidant activity, and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (Tyr) inhibitory capacities. Ten different NADES were used in this research and compared with conventional solvents. Ultrasound-assisted extraction (UAE) for 60 min proved to be the best extraction condition, and proline:lactic acid (1:1) and choline chloride:urea (1:2) extracts showed the highest total phenolic contents (56.00 ± 0.77 mgGAE/gdw) and antioxidant activity [64.35 ± 1.74 mgTE/gdw and 72.13 ± 0.97 mgTE/gdw in 2.2-diphenyl-1-picrylhydrazyl (DPPH) and 2.2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, respectively]. These extracts also exhibited enzymes inhibitory capacity particularly against Tyr and AChE. Even so, organic acid-based NADES showed to be the best extractants producing extracts with considerable ability to inhibit enzymes. Twenty-four phenolic compounds were identified by HPLC-HRMS, being rosmarinic acid, ferulic acid and salvianolic acid B the major compounds. The results confirmed that the combination of UAE and NADES provide an excellent alternative to organic solvents for sustainable and green extraction, and have huge potential for use in industrial applications involving the extraction of bioactive compounds from plants.


2021 ◽  
Vol 68 (3) ◽  
pp. 658-666
Author(s):  
Izzet Turker ◽  
Hilal Isleroglu

In this study, bioactive compounds were extracted by ultrasonic-assisted extraction and classical extraction processes using distilled water as solvent from artichoke leaves which are considered as agricultural wastes. Antioxidant capacity, total phenolic and total flavonoid content values of the obtained bioactive extracts were determined, and extraction yields and times were evaluated to compare the extraction processes. Also, the optimum extraction conditions of ultrasonic-assisted extraction (extraction time and ultrasonic power) which provide the highest extraction yield were determined using D-optimal design by ‘desirability’ function approach. According to the results, bioactive extracts having high antioxidant capacity were obtained at shorter times and higher extraction yields were achieved by ultrasonic-assisted extraction process than classical extraction. The highest extraction yield was estimated as 98.46% with an application of 20.05 minutes of extraction time and 65.02% of ultrasonic amplitude for the ultrasonic-assisted extraction process.


2019 ◽  
Vol 8 (3) ◽  
pp. 104
Author(s):  
Bambang Kunarto ◽  
Sutardi Sutardi ◽  
Supriyanto Supriyanto ◽  
Chairil Anwar

Biji melinjo kerikil mengandung senyawa fenolik dan resveratrol sehingga berpotensi sebagai antioksidan, oleh karena itu perlu dilakukan ekstraksi. Metoda ekstraksi konvensional (maserasi, perebusan, refluxing) mempunyai kelemahan yaitu terjadinya kerusakan senyawa fenolik akibat reaksi oksidasi, hidrolisis dan ionisasi selama proses ekstraksi. Oleh karena itu, pada penelitian ini ekstraksi biji melinjo kerikil dilakukan menggunakan metode ekstraksi berbantu gelombang ultrasonik. Penelitian ini bertujuan untuk optimasi ekstraksi biji melinjo kerikil berbantu gelombang ultrasonik yang dilakukan pada berbagai waktu ekstraksi, suhu ekstraksi dan konsentrasi pelarut etanol. Surface response methodology digunakan untuk optimasi kondisi ekstraksi. Biji melinjo kerikil diekstrak menggunakan ultrasonic bath pada frekuensi 40 kHz dengan berbagai suhu (25, 30, 35, 40, 45oC), waktu ekstraksi (10, 20, 30, 40, 50 menit) dan konsentrasi pelarut etanol (40, 50, 60, 70 80%). Hasil penelitian menunjukkan bahwa kondisi optimum ekstraksi biji melinjo kerikil berbantu gelombang ultrasonik adalah pada suhu 30,18oC, waktu 33,01 menit dan konsentrasi pelarut etanol 71,04%. Pada kondisi ini, diperoleh yield ekstrak 18,41 ± 0,01%, total fenolik 11,26 ± 0,06 mg GAE/g, total flavonoid 533,70 ± 0,18 mg CE/100g, resveratrol 7,64 ± 0, 03%, IC50 sebesar 59,52 ± 0,04 ppm dan reducing power 76,31 ± 0,08%. Sebagai kesimpulan, optimasi ekstraksi biji melinjo kerikil berbantu gelombang ultrasonik menggunakan response surface methodology ini cukup baik karena nilai respon yang sebenarnya sesuai dengan nilai respon yang diprediksi.Melinjo kerikil seeds contain phenolic and resveratrol compounds so that it has the potential as an antioxidant, therefore extraction needs to be done. Conventional extraction methods (maceration, boiling, refluxing) have the disadvantage of devasting phenolic compounds due to oxidation, hydrolysis and ionization reactions during the extraction process. Therefore, in this study the extraction of melinjo kerikil seeds done by using the ultrasonic-assisted extraction method. The study aims to optimize ultrasonic-assisted extraction of melinjo kerikil seeds that be done at various extraction times, extraction temperatures and ethanol solvents concentrations. Response surface methodology was used to optimize experimental condition for extraction. Melinjo kerikil seeds were extracted by using ultrasonic bath at a frequency of 40 kHz with various temperatures (25, 30, 35, 40, 45oC), extraction time (10, 20, 30, 40, 50 minutes) and ethanol solvents concentrations (40, 50, 60, 70 80 %). The results showed that the optimum conditions for ultrasonic-assisted extraction of melinjo kerikil seeds were at a temperature of 30.18oC, a time of 33.01 minutes and an ethanol solvent concentration of 71.04%. In this condition, obtained the extract yield 18.41 ± 0.01%, total phenolic 11.26 ± 0.06 mg GAE/g, total flavonoids 533.70 ± 0.18 mg CE/100g, resveratrol 7.64 ± 0,03%, IC50 in the amount of 59.52 ± 0.04 ppm and reducing power 76.31 ± 0.08%. As a conclusion, the optimization ultrasonic-assisted extraction of melinjo kerikil seeds by using response surface methodology is quite good because the actual response value is in accordance with the predicted response value.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Nurul Shazini Ramli ◽  
Patimah Ismail ◽  
Asmah Rahmat

The aim of this study was to examine the effects of extraction methods on antioxidant capacities of red dragon fruit peel and flesh. Antioxidant capacities were measured using ethylenebenzothiozoline-6-sulfonic acid (ABTS) radical cation assay and ferric reducing antioxidant power assay (FRAP). Total phenolic content (TPC) was determined using Folin-Ciocalteu reagent while quantitative determination of total flavonoid content (TFC) was conducted using aluminium trichloride colorimetric method. Betacyanin content (BC) was measured by spectrophotometer. Red dragon fruit was extracted using conventional (CV) and ultrasonic-assisted extraction (UE) technique to determine the most efficient way of extracting its antioxidant components. Results indicated that UE increased TFC, reduced the extraction yield, BC, and TPC, but exhibited the strongest scavenging activity for the peel of red dragon fruit. In contrast, UE reduced BC, TFC, and scavenging activity but increased the yield for the flesh. Nonetheless, UE slightly increases TPC in flesh. Scavenging activity and reducing power were highly correlated with phenolic and flavonoid compounds. Conversely, the scavenging activity and reducing power were weakly correlated with betacyanin content. This work gives scientific evidences for the consideration of the type of extraction techniques for the peel and flesh of red dragon fruit in applied research and food industry.


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