scholarly journals Valorization of Cork Using Subcritical Water

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4695
Author(s):  
Mónica Cunha ◽  
Ana Lourenço ◽  
Susana Barreiros ◽  
Alexandre Paiva ◽  
Pedro Simões

Granulated cork was submitted to subcritical water extraction/hydrolysis in a semi-continuous reactor at temperatures in the range of 120–200 °C and with a constant pressure of 100 bar. The influence of temperature on the composition of the cork extracts obtained was assessed—namely, their content of carbohydrates and phenolics. The extraction yield increased with the temperature, and this was associated with the decrease in the dielectric constant of water and the increase in its ionic product. Extracts composed of up to 36% phenolics were obtained at temperatures of up to 120 °C, with an antioxidant activity only two times lower than that of pure gallic acid, but in low amounts. Assays at higher temperatures generated extracts richer in carbohydrates and with a phenolics content of ca. 20 wt.% in comparatively far higher amounts. Neither the amount of suberin nor its structure were affected by the subcritical water treatment.

2022 ◽  
Vol 25 ◽  
pp. 100593
Author(s):  
Ana Margarida Silva ◽  
Ana Sofia Luís ◽  
Manuela M. Moreira ◽  
Ricardo Ferraz ◽  
Tanja Brezo-Borjan ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2774 ◽  
Author(s):  
Tanja Gagić ◽  
Željko Knez ◽  
Mojca Škerget

The aim of the work was the optimization of the subcritical water extraction process of chestnut bark using Box–Behnken response surface methodology. The influence of process parameters, such as temperature, extraction time and solvent-solid ratio, on extraction yield, yield of the main compounds, total phenol content, total tannin content and antioxidant activity has been investigated. The identified compounds were ellagic and gallic acids, ellagitannins (vescalagin, castalagin, 1-o-galloyl castalagin, vescalin and castalin), sugars (maltose, glucose, fructose and arabinose) and sugar derivatives (5-HMF, furfural and levulinic acid). Finally, the optimal process conditions for obtaining the bark extract highly rich in ellagic acid and with satisfactory levels of total phenols and total tannins have been determined.


2021 ◽  
Vol 10 (8) ◽  
pp. e5510817024
Author(s):  
Vanessa Barbieri Bombana ◽  
Carolina Elisa Demaman Oro ◽  
Diane Rigo ◽  
Caroline Chies Polina ◽  
Andressa Franco Denti ◽  
...  

The objective of this work was to evaluate the influence of temperature on the content of bioactive compounds of fruits of guabiju (Myrcianthes pungens (O. Berg) D. Legrand). The peel, pulp and seed of fresh guabiju were analyzed in relation to physical-chemical composition, metals, color, phenolic compounds, flavonoids, anthocyanins, vitamin C and antioxidant activity. On the dehydrated samples at temperature of 60 °C, where also determined the moisture and water activity. The fractions of the fruit showed high amounts of metals. After drying, moisture of 1.3, 1.0 and 0.9% were observed for peel, pulp and seed and water activity of 0.44 to 0.54. All the samples darkened, with less variation in the dehydrated peel (∆E 9.2). The samples showed high values of bioactive compounds, and in the fresh peel were observed higher levels of phenolic compounds (8459.8 mg EGA/100g dry extract), anthocyanins (152.0 mg/100 dry extract) and vitamin C (222.9 mg/100g) and on the dehydrated seed higher value of flavonoids (7480.7 mg EQ/100g dry extract). There was 86.3% degradation of anthocyanins in the dehydrated peel. The best values of antioxidant activities were obtained for the dehydrated peel (IC50 1.37 mg/mL), seed (IC50 1.49 mg/mL) and in the fresh peel (IC50 1.41 mg/mL).


2013 ◽  
Vol 662 ◽  
pp. 293-296 ◽  
Author(s):  
Yan Cheng ◽  
Jing Liu ◽  
Chang An Liu

The extraction of baicalin, baicalein, wogonin and wogonoside from Scutellaria Baicalenses was performed using subcritical water. The effects of key operation conditions by varying the temperature (110-160 °C), extraction time (10-90 min), water loadings (2.0-4.0 mL)and particle sizes (>20- <100 mesh) were evaluated. The highest extraction yields of baicalin and wogonoside were obtained at extraction temperature of 160 °C, extraction time of 60 min, water loadings of 4.0 mL and 60-100 mesh. The highest extraction yields of baicalein and wogonin were obtained at extraction temperature of 110 °C, extraction time of 10 min, water loadings of 4.0 mL and 60-100 mesh. The subcritical water extraction was compared with the conventional extraction method. The total extraction yield by SCWE was higher than those obtained using ethanol as the solvent.


2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Hongyi Sun ◽  
Xi Yuan ◽  
Zhenya Zhang ◽  
Xin Su ◽  
Min Shi

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.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1878
Author(s):  
Jelena Vladić ◽  
Martina Jakovljević ◽  
Maja Molnar ◽  
Senka Vidović ◽  
Milan Tomić ◽  
...  

In the present study, valorization of yarrow (Achillea millefolium) by-product from the filter tea industry was investigated through the application of subcritical water for the extraction of bioactive compounds. The influence of different process parameters (temperature 120–200 °C, extraction time 10–30 min, and HCl concentration in extraction solvent 0–1.5%) on extract quality in terms of content of bioactive compounds and antioxidant activity was investigated. Optimal conditions of the extraction process (temperature 198 °C, extraction time 16.5 min, and without acidifer) were determined and, when applied, the most efficient exploitation of by-products is achieved, that is, attainment of extracts rich in total phenols and flavonoids and high antioxidant activity. In addition, by applying the high performance liquid chromatographic analysis, the content of chlorogenic acid was determined as well as the hydroxymethylfurfural content in obtained extracts. The results demonstrated that subcritical water can be successfully used for utilization of yarrow by-products for obtaining extracts rich in antioxidants.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Nur Athirah Zabidi ◽  
Nur Akmal Ishak ◽  
Muhajir Hamid ◽  
Siti Efliza Ashari

This study aims to extract antioxidant compounds from Curculigo latifolia root by subcritical water extraction (SWE). The influence of extraction temperature and time on the antioxidant activity of C. latifolia root extract was investigated in terms of extraction yield, total phenolic content (TPC), total flavonoid content (TFC), 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The highest extraction yield (36.5%), TPC (92.55 mg GAE/g), TFC (13.26 mg RE/g), and antioxidant activities by ABTS (66.8 mg trolox equivalent/g sample) and DPPH (128.7 mg trolox equivalent/g sample) were detected at 180°C and 30 minutes extraction time. Based on the results, the optimum condition was selected at 180°C and 30 minutes of extraction. The sample was screened by using liquid chromatography-mass spectrometry (LC-MS) analysis where the phenolic compounds detected were structured based on their [M-H]-peak. The detected phenolic compounds were monobenzone, hydroquinone, phloridzin, pomiferin, mundulone, scandenin, and dimethyl caffeic acid. According to these findings, SWE is a promising, environmentally friendly, and efficient technology in the exploitation of natural products for the development of food and nutraceutical commodities.


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