Composition of Phenolic Compounds and Antioxidant Activities of Subcritical Water Extracts of Onion Skin

2018 ◽  
Vol 47 (4) ◽  
pp. 403-413
Author(s):  
Dong-Shin Kim ◽  
Sang-Bin Lim
Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1233
Author(s):  
Óscar Benito-Román ◽  
Beatriz Blanco ◽  
María Teresa Sanz ◽  
Sagrario Beltrán

The valorization of onion skin wastes (OSW) through the extraction, identification, and quantification of phenolic compounds was studied in this work, using subcritical water in a semicontinuous extractor (2.5 mL/min; 105–180 °C; 5 MPa). The extraction of flavonoids resulted to be fast (<30 min) and temperature sensitive (maximum at 145 °C; total flavonoids, 27.4 ± 0.9 mg/g dry OSW (DOSW)). The experimental results were fitted to the Weibull model. The influence of the solvent properties on the flavonoids quantification was found to be critical. A precipitate was formed once the extracts cooled down. If removed, a significant fraction of the high temperature extracted flavonoids (as much as 71%, at 180 °C) was lost. Such a condition affected especially those compounds that show extremely low solubility in water at room temperature, whereas quercetin glycosylated derivatives were less affected by the polarity change of the medium induced by the temperature change. It was demonstrated that it is necessary to re-dissolve the subcritical water extracts by the addition of ethanol, which led to a medium with a polarity equivalent to that obtained with water at high temperature. At 145 °C, quercetin (15.4 ± 0.4 mg/g DOSW) and quercetin-4′-glucoside (8.4 ± 0.1 mg/g DOSW) accounted for the 90% of the total flavonoids identified. By recovering high added value bioactive compounds from OSW the principles of circular economy were fulfilled, providing a new use for this agricultural waste.


2020 ◽  
Vol 3 (1) ◽  
pp. 47
Author(s):  
Nadezhda Petkova ◽  
Manol Ognyanov ◽  
Blaga Inyutin ◽  
Petar Zhelev ◽  
Panteley Denev

Crab apple (Malus baccata (L.) Borkh.) was mainly distributed in Europe as an ornamental plant, but the nutritional properties of its edible fruits were not fully revealed. The aim of the current study was to characterize the phytochemical composition of ripen carb apple fruits and to evaluate their nutritional and antioxidant potentials. The fruits were assayed for moisture and ash content, proteins, lipids, carbohydrates, titratable acidity (TA), pH, total phenolic compounds and natural pigments. Among the analyzed carbohydrates cellulose was found in the highest content (6% dw), followed by sugars (sucrose, glucose and fructose) and 1.8 % dw uronic acids. The total chlorophylls and carotenoids contents in their fruits were 6.51 and 4.80 μg/g fw, respectively. Total monomeric anthocyanins were not detected. The highest content of total phenolic compounds (2.67 mg GAE/g fw) was found in 95 % ethanol extract from fruits, while the total flavonoids were relatively low – 0.1 mg QE/g fw. DPPH assay (17.27 mM TE/g fw) and FRAP assay (14.34 mM TE/g fw) demonstrated in vitro antioxidant activities of crabapple. Malus baccata fruits were evaluated as a rich source of dietary fibers and phenolic compounds with significant antioxidant potential that could be used in human nutrition.


2018 ◽  
Vol 17 (4) ◽  
pp. 337-348
Author(s):  
Bai Zhouya ◽  
Huang Xiaojun ◽  
Meng Jinxia ◽  
Kan Lijiao ◽  
Nie Shaoping

Distribution of phenolic compounds and antioxidant activities was surveyed in 24 varieties of Chinese cowpea from 4 provinces. Identity of phytochemicals were determined by UPLC-ESIQTOF-MS/MS and quantified by HPLC-ESI-QqQ-MS/MS. Seven phenolic acids, 16 flavonoids and 9 other compounds were identified and several of these were quantified. Quercetin-3-glucoside and kaempferol-glucoside were the major phenolic compounds. In addition, our study indicated that OJYDH cultivar from Jiangxi province had the highest total phenolic content, total flavonoid content and stronger antioxidant activities than other cowpea cultivars. This study made a comprehensive investigation on antioxidants from cowpea and provided the useful data to support its function.


2008 ◽  
Vol 37 (5) ◽  
pp. 542-547 ◽  
Author(s):  
Myeon Choe ◽  
Dae-Jung Kim ◽  
Hyeon-Ju Lee ◽  
Jin-Kyoun You ◽  
Dong-Joo Seo ◽  
...  

2021 ◽  
Vol 41 (02) ◽  
pp. 138-144
Author(s):  
Lucas Petitemberte de Souza ◽  
Henrique Sarubbi Fillmann ◽  
Sandielly Rebeca Benitez da Fonseca ◽  
Marilda da Silva Brasil ◽  
Norma Anair Possa Marroni ◽  
...  

AbstractDue to the ethnopharmacological use of Campsiandra laurifolia (Fabaceae), popularly known as Acapurana, to treat wounds and ulcers, associated with the lack of alternative treatments for intestinal inflammations such as ulcerative colitis (UC), the present work sought to characterize its phytochemical and antioxidant activities, and to evaluate remedial action in experimental colitis with acetic acid. Phytochemical analyzes were performed through qualitative and quantitative colorimetric tests of the main secondary metabolites. In the colitis model, 24 male Wistar rats aged ± 60 days old were used, divided into 4 groups: Control (CO) control + aqueous extract of C. laurifolia 50 mg/kg (CO + A50); Colitis (CL); and Colitis + aqueous extract of C. laurifolia 50 mg/kg (CL + A50). Measurement of sphincter anal pressure and histological tests of the large intestine, lipoperoxidation (LPO), enzyme activity of superoxide dismutase (SOD), and levels of glutathione (GSH) were performed. For statistical analysis, the oxidative stress (OS) results were expressed as means ± standard error, adopting a significance level of p < 0.05. The screening indicated the presence of flavonoids, saponins and tannins in the extract, with high levels of phenolic compounds and tannins, and was related to high antioxidant capacity. In the histological analysis, the CL group presented loss of the crypts, edema and inflammatory infiltrate. The use of C. laurifolia extract restructured the crypts, decreased edema and increased sphincter anal pressure, with a decrease in LPO, SOD, and an increase in GSH. It is suggested that the use of C. laurifolia extract reduces OS due to its antioxidant power conferred by the phenolic compounds present in the extract.


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