Subcritical water extraction of Diosgenin from Dioscorea nipponica Makino and its antioxidant activity

Subcritical water extraction (SWE) has been employed for the extraction of bioactive compounds from plant materials with cost-effectiveness, less consuming time, and environmental sustainability. To explore the effects of thermal processing during SWE, total organic content (TOC), total sugar, polysaccharides, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (ABTS and DPPH assays) of eight aqueous extracts have been quantitatively investigated. The results indicated that elevated temperatures indeed resulted in significant changes in the constituents and antioxidant activities of okara extracts. Among them, the extract obtained at 220°C exhibited the highest total phenolic, flavonoid content, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical-scavenging activity. However, phenolic compounds were destroyed after the treatment above 230°C, suggesting that any polymer processing is improper to undertake at higher than this value to achieve the high antioxidant activity. Moreover, a significant positive correlation between TPC or TFC and antioxidant capacity (DPPH and ABTS) values was detected.

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Subcritical water extraction of antioxidant compounds from Seabuckthorn (Hippophae rhamnoides) leaves for the comparative evaluation of antioxidant activity

Food Chemistry ◽

10.1016/j.foodchem.2011.01.088 ◽

2011 ◽

Vol 127 (3) ◽

pp. 1309-1316 ◽

Cited By ~ 83

Author(s):

M.S. Yogendra Kumar ◽

Ruma Dutta ◽

Dipti Prasad ◽

Kshipra Misra

Keyword(s):

Antioxidant Activity ◽

Comparative Evaluation ◽

Subcritical Water ◽

Water Extraction ◽

Hippophae Rhamnoides ◽

Antioxidant Compounds ◽

Subcritical Water Extraction ◽

Hippophaë Rhamnoides

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Subcritical water extraction of horse chestnut (Aesculus hippocastanum) tree parts

Journal of the Serbian Chemical Society ◽

10.2298/jsc201111013g ◽

2021 ◽

Vol 86 (6) ◽

pp. 603-613

Author(s):

Tanja Gagic ◽

Zeljko Knez ◽

Mojca Skerget

Keyword(s):

Antioxidant Activity ◽

Subcritical Water ◽

Batch Reactor ◽

Water Extraction ◽

Aesculus Hippocastanum ◽

Horse Chestnut ◽

Total Phenol Content ◽

Subcritical Water Extraction ◽

Spectrophotometric Methods ◽

Total Carbohydrates

Subcritical water extraction of horse chestnut (Aesculus hippocastanum) parts, such as seeds, seed shell, bark and leaves has been performed in a batch reactor at temperatures of 150, 200 and 250?C and extraction times of 5, 15 and 30 min. The obtained extracts were analyzed by spectrophotometric methods to determine the total phenols, total carbohydrates and antioxidant activity. Furthermore, the compounds detected in the extracts, such as triterpene saponins (escins), coumarin glycosides (esculin and fraxin), phenolic compounds (chlorogenic, neochlorogenic and gallic acids) and furfurals (5-hydroxymethyfurfural, furfural, and 5-methylfufrual) were quantified using HPLC. High amount of escins was obtained in the seed extracts, while the highest amounts of esculin and fraxin were obtained in bark extracts. The total phenol content was the highest in shell and bark extracts, which implies that these extracts gave the highest antioxidant activity.

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Comparative in vitro Study of the biological activity and chemical composition extracts of Helicteres isora L. obtained by water and subcritical water extraction

Food Quality and Safety ◽

10.1093/fqsafe/fyz038 ◽

2019 ◽

Vol 4 (2) ◽

pp. 101-106

Author(s):

Zohreh Didar

Keyword(s):

Antioxidant Activity ◽

Chemical Composition ◽

Enzymatic Activity ◽

Microbial Activity ◽

Subcritical Water ◽

Water Extract ◽

Water Extraction ◽

Subcritical Water Extraction ◽

Helicteres Isora ◽

Water Ratio

Abstract Objectives Subcritical water extraction technique is considered as an environmentally extraction technique. The aim of this study was to compare the different characteristics of water extract and subcritical water extract of Helicteres isora L. Materials and Methods Water extraction was performed under the following conditions: 25°C, 24 h, and solid-to-water ratio 1:30. Subcritical water extract was carried out under specific conditions (pressure = 10 bar, temperature = 160°C, solid-to-water ratio = 1: 30, time = 30 min). Chemical composition analysis was performed using GC–Mass chromatography. Anti-biofilm activity in the terms of anti-attach and removal of biofilm were assessed using the ELISA reader method and reading absorbance at 570 nm. Anti-microbial activity against Bacillus cereus, Staphylococcus aureus, Staphylococcus saprophyticus, and Bacillus subtilis was investigated by measurement of inhibitory zone diameter. Anti-enzymatic and antioxidant properties were also assessed. Results The results of GC–Mass analysis showed some components extracted in subcritical method which were absent in water extract such as octadecanoic acid, hexadecanoic acid, and berberin. Antioxidant activity of the two tested extracts revealed that subcritical water extract had more antioxidant capacity than water extract (P ≤ 0.05). The two tested extracts exhibited anti-enzymatic activity against polyphenol oxidase enzyme with better performance of subcritical water extract. Anti-biofilm activity of the two extracts implies that, in the case of preventing biofilm formation, both extracts had similar efficiency but in the removal of biofilm, subcritical water extract showed better performance. Both extracts had anti-microbial activity against B. cereus, S. aureus, S. saprophyticus, and B. subtilis with better performance of subcritical water extract. Anti-enzymatic assay also showed similar results. Conclusions Subcritical water extract of H. isora showed more antioxidant activity as well as anti-biofilm, anti-bacterial, and anti-enzymatic activity rather than ordinary water extract.

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