scholarly journals Chemical, Thermal and Antioxidant Properties of Lignins Solubilized during Soda/AQ Pulping of Orange and Olive Tree Pruning Residues

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3819
Author(s):  
María E. Eugenio ◽  
Raquel Martín-Sampedro ◽  
José I. Santos ◽  
Bernd Wicklein ◽  
David Ibarra

Some agroforestry residues such as orange and olive tree pruning have been extensively evaluated for their valorization due to its high carbohydrates content. However, lignin-enriched residues generated during carbohydrates valorization are normally incinerated to produce energy. In order to find alternative high added-value applications for these lignins, a depth characterization of them is required. In this study, lignins isolated from the black liquors produced during soda/anthraquinone (soda/AQ) pulping of orange and olive tree pruning residues were analyzed by analytical standard methods and Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (solid state 13C NMR and 2D NMR) and size exclusion chromatography (SEC). Thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC)) and antioxidant capacity (Trolox equivalent antioxidant capacity) were also evaluated. Both lignins showed a high OH phenolic content as consequence of a wide breakdown of β-aryl ether linkages. This extensive degradation yielded lignins with low molecular weights and polydispersity values. Moreover, both lignins exhibited an enrichment of syringyl units together with different native as well as soda/AQ lignin derived units. Based on these chemical properties, orange and olive lignins showed relatively high thermal stability and good antioxidant activities. These results make them potential additives to enhance the thermo-oxidation stability of synthetic polymers.

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1187
Author(s):  
Manyou Yu ◽  
Irene Gouvinhas ◽  
Ana Barros

In recent decades, an intensive search for natural and novel types of antioxidant polyphenolics has been carried out on numerous plant materials. However, the current literature has very little information on their storage stability in the form of freshly prepared infusions. This study aims to characterize the polyphenolic composition and the antioxidant capacity of pomegranate (Punica granatum L.) leaf infusions over one-day storage (analyzed at 0, 2, 4, 6, 8, and 24 h). Spectrophotometric evaluation demonstrated that the infusion presented no significant changes in the content of total phenols (131.40–133.47 mg gallic acid g−1) and ortho-diphenols (239.91–244.25 mg gallic acid g−1). The infusion also maintained high stability (over 98% and 82%, respectively) for flavonoids (53.30–55.84 mg rutin g−1) and condensed tannins (102.15–124.20 mg epicatechin g−1), with stable (>90%) potent antioxidant capacity (1.5–2.2 mmol Trolox g−1) throughout 0–24 h storage. The main decrease was observed during 0–2 h storage of flavonoids, 8–24 h storage of tannins, and 0–4 h storage of antioxidant capacity. Chromatographic analysis further revealed that 7 decreased and 11 increased compounds were found within 0–24 h storage. The good stability of the total polyphenolics and antioxidant properties might be related to the complex conversion and activity compensation among these compounds. The findings suggest that pomegranate leaf infusion could be of great interest in the valorization of high added-value by-products and in the application of green and functional alternatives in the food-pharma and nutraceutical industries.


Author(s):  
Julian Alfke ◽  
Uta Kampermann ◽  
Svetlana Kalinina ◽  
Melanie Esselen

AbstractDietary polyphenols like epigallocatechin-3-gallate (EGCG)—which represents the most abundant flavan-3-ol in green tea—are subject of several studies regarding their bioactivity and health-related properties. On many occasions, cell culture or in vitro experiments form the basis of published data. Although the stability of these compounds is observed to be low, many reported effects are directly related to the parent compounds whereas the impact of EGCG degradation and autoxidation products is not yet understood and merely studied. EGCG autoxidation products like its dimers theasinensin A and D, “P2” and oolongtheanin are yet to be characterized in the same extent as their parental polyphenol. However, to investigate the bioactivity of autoxidation products—which would minimize the discrepancy between in vitro and in vivo data—isolation and structure elucidation techniques are urgently needed. In this study, a new protocol to acquire the dimers theasinensin A and D as well as oolongtheanin is depicted, including a variety of spectroscopic and quadrupole time-of-flight high-resolution mass spectrometric (qTOF-HRMS) data to characterize and assign these isolates. Through nuclear magnetic resonance (NMR) spectroscopy, polarimetry, and especially circular dichroism (CD) spectroscopy after enzymatic hydrolysis the complementary atropisomeric stereochemistry of the isolated theasinensins is illuminated and elucidated. Lastly, a direct comparison between the isolated EGCG autoxidation products and the monomer itself is carried out regarding their antioxidant properties featuring Trolox equivalent antioxidant capacity (TEAC) values. These findings help to characterize these products regarding their cellular effects and—which is of special interest in the flavonoid group—their redox properties.


2021 ◽  
pp. 1-13
Author(s):  
Imen Landolsi ◽  
Narjes Rjiba ◽  
Mohamed Hamdaoui ◽  
Omar Anis Harzallah ◽  
Chedly Boudokhane

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Lizbeth A. Castro-Concha ◽  
Jemina Tuyub-Che ◽  
Angel Moo-Mukul ◽  
Felipe A. Vazquez-Flota ◽  
Maria L. Miranda-Ham

In the past few years, there has been a renewed interest in studying a wide variety of food products that show beneficial effects on human health.Capsicumis an important agricultural crop, not only because its economic importance, but also for the nutritional values of its pods, mainly due to the fact that they are an excellent source of antioxidant compounds, and also of specific constituents such as the pungent capsaicinoids localized in the placental tissue. This current study was designed to evaluate the antioxidant capacity and total phenolic contents from fruits tissues of twoCapsicum chinenseaccessions, namely, Chak k’an-iik (orange) and MR8H (red), at contrasting maturation stages. Results showed that red immature placental tissue, with a Trolox equivalent antioxidant capacity (TEAC) value of 55.59 μmols TE g−1 FW, exhibited the strongest total antioxidant capacity using both the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the CUPRAC methods. Placental tissue also had the highest total phenolic content (27 g GAE 100 g−1 FW). The antioxidant capacity ofCapsicumwas directly related to the total amount of phenolic compounds detected. In particular, placentas had high levels of capsaicinoids, which might be the principal responsible for their strong antioxidant activities.


Author(s):  
LAURA GONZÁLEZ ◽  
ANDREE ÁLVAREZ ◽  
ELIZABETH MURILLO ◽  
CARLOS GUERRA ◽  
JONH MÉNDEZ

Objective: Assess the performance of a crude ethanolic extract, a dichloromethane fraction and a hydroalcoholic residue, which are the basis for chemically and biologically characterizing the husk and seed of Passiflora edulis f. edulis, collected in the region and Colombia with a view to determining potential uses. Methods: Agroindustrial residues of gulupa (peel and seed) were analyzed through a bromatological study; subsequently, they were macerated with ethanol (96%). The crude ethanolic extract was partitioned with dichloromethane, leaving a hydroalcoholic residue. The content of total phenols, the composition of phytophenols (high-performance liquid chromatography-mass spectrometry), the total antioxidant capacity using 3-ethyl benzothiazoline-6-sulfonic acid (ABTS●+) and 2,2-diphenyl-1-pyridyl hydrazyl (DPPH●), the oxygen radical absorbance capacity (ORAC), and the ferric reduction power (FRAP) were determined to the extract, the fraction, and the residue. The evaluation of the inhibitory activity of the angiotensin-converting enzyme inhibitor (ACEI) and the cell viability assay with diphenyl bromide 3- (4,5-dimethylthiazole-2-) il) -2,5-tetrazolium on human leukocytes complemented the characterization. Results: Agroindustrial waste of P. edulis f. edulis, peel and seed, contains as main constituents: Protein (8.49 and 7.29%), fiber (34.2 and 55.7%), phosphorus (1.67 and 3.09), and boron (53.3 and 58.4 mg/kg), respectively. The seed showed 25.5% oil. The crude seed extract exhibited a higher phenolic content (15.34 gEAG/100 g). Likewise, it presented the highest antiradical capacity against ABTS●+ and DPPH● (706.17 and 82.81 trolox equivalent antioxidant capacity [TEAC], respectively) and antioxidant in ORAC and FRAP (142.79 TEAC and 103.63 equivalent ascorbic acid EAA, respectively). The ACEI activity (50% inhibitory concentration 17.62 mg/L) of the crude seed extract was higher than the other samples. No toxicity was found in the samples evaluated at concentrations higher than those of the biological activities manifested. Conclusion: The agroindustrial residues of P. edulis f. edulis (peel and seed) are rich in nutrients, which propose them for use in food matrices. The ethanolic extract from seed showed the highest antioxidant, antiradical, and inhibitory biological activity of the ACEI so that it could be proposed the gulupa seed as a promising phytotherapeutic product associated with its phenolic content, especially its flavonoids. The results obtained allow an added value to the fruit, reducing the chances that its waste contributes to environmental pollution.


2007 ◽  
Vol 20 (3) ◽  
pp. 585-593 ◽  
Author(s):  
G. Cinnella ◽  
G. Vendemiale ◽  
M. Dambrosio ◽  
G. Serviddio ◽  
P.L. Pugliese ◽  
...  

We studied the effects of Propofol, Desflurane, and Sevoflurane on the systemic redox balance in patients undergoing laparohysterectomy. We measured blood concentration of glutathione (GSH), plasma antioxidant capacity (Trolox Equivalent Antioxidant Capacity-TEAC), and lipid peroxidation products (malondialdehyde (aMDA) and 4-hydroxynonenal (aHNE) protein adducts). Sixty patients were randomly placed into three groups of twenty people each. In Group P anesthesia was induced with Propofol 2 mg/kg and maintained with 12–10–8 mg/kg/min; in Groups S and D anesthesia was induced with 3 mg/kg Sodium Thiopental and maintained with 2% Sevoflurane and 6% Desflurane, respectively. Blood samples were collected prior to induction (T0bas), 60min and 24h postoperatively (T160' and T224 h). In Group P, GSH increased on T160' (p<0.02) and returned to baseline on T24h, while TEAC remained unmodified; in Groups S, GSH and TEAC decreased on T160' (p<0.01 vs. T0bas, p<0.03 vs. T0bas, respectively); in Group D, on T160' there was a slight decrease of GSH and TEAC. The levels of aMDA slightly decreased throughout the study periods in Group P, increased in Group D, and remained stable in Group S. Propofol showed antioxidant properties, while Sevoflurane and Desflurane seemed to shift the redox balance towards oxidation, yet without inducing overt oxidative damage.


2020 ◽  
Vol 122 (10) ◽  
pp. 3029-3038
Author(s):  
Seok Shin Tan ◽  
Seok Tyug Tan ◽  
Chin Xuan Tan

PurposeSalak (Salacca zalacca) is an underutilised fruit. The bioactivities of this fruit have rarely been studied scientifically. Thus, the present study aimed to determine the antioxidant activity of extracts derived from the peel, fruit and kernel of the Salak fruit, as well as the hypoglycemic and anti-hypertensive properties of Salak peel extracts.Design/methodology/approachThe peel, fruit and kernel of the Salak were extracted using distilled water, methanol and ethanol. Antioxidant activities, angiotensin-converting enzyme (ACE) and alpha-amylase inhibition properties of the extracts were estimated via in vitro standard methods. Besides, the total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were also determined in the present study. The antioxidant activities of different parts of Salak extracts were determined by ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) methods. Percent of radical scavenging properties were calculated via DPPH assay. The hypoglycemic and anti-hypertensive properties of Salak peel were evaluated using alpha-amylase inhibition and ACE assays, respectively.FindingsFruit extracts of Salak in methanol were found to exhibit the highest TPC (10.27 ± 0.12 mg GAE/g), TFC (11.04 ± 0.89 mg CE/g) and antioxidant properties amongst all samples whereby the TPC and TFC were strongly correlated with antioxidant activities. On the other hand, distilled water extracted Salak kernel showed to have the lowest TPC (0.53 ± 0.05 mg GAE/g), TFC (0.37 ± 0.01 mg CE/g) and antioxidant properties amongst all the Salak extracts. Peel extracts exhibit comparable antioxidant activities with fruit extracts in the current findings. In addition, peel extracts indicated some extend of ACE and alpha-amylase inhibition activities regardless of the solvents used. Methanol and ethanol peel extracts indicated no significant difference (p < 0.05) ACE (98%) and alpha-amylase (90%) inhibition activities. However, distilled water extracted Salak peel showed significantly lower ACE and alpha-amylase inhibition in comparison to methanol and ethanol peel extracts.Originality/valueThe present findings suggested that the fruit of Salak exhibits the highest antioxidant properties, followed by the peel and lastly, the kernel, which shows the lowest antioxidant properties amongst all the samples. The results also indicated that the peel extracts have ACE and alpha-amylase inhibition activities.


2020 ◽  
Vol 4 (4) ◽  
pp. 193-201
Author(s):  
Bei Liu ◽  
Qingqing Xu ◽  
Yujing Sun

Abstract Goji berry tea, a traditional herbal tea, is the main ate mode of goji berry in Asia, yet few studies in comparison with red goji berry tea and black goji berry tea are carried out. This study investigated the effects of water temperature and soak time on the colour, phytochemicals, and the antioxidant capacity [2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), and the ferric-reducing antioxidant power (FRAP)] of two goji berry tea. A comparison of the bioactive compounds and antioxidant activities between black and red goji berry tea was conducted. Results showed that both red and black goji berry tea were rich in phytochemicals, giving high antioxidant ability. The levels of bioactive compounds and the antioxidant activity of the two goji berry tea increased as the increases in soak temperature and time. Black goji berry tea had higher phytochemicals and antioxidant property than those of red goji berry tea. Infused at 100° water for the same time, the levels of total polysaccharides (150 mg/100 ml), total polyphenols (238 mg/ml), and antioxidant capacity (550 μmol/100 ml) of black goji berry tea were 3.5, 2, and 5 times higher, respectively, in comparison with red goji berry tea. The results of this study demonstrate that hot drink of goji berry in China is a good habit and black goji berry tea may be a better choice.


BMC Neurology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mansoureh Togha ◽  
Soodeh Razeghi Jahromi ◽  
Zeinab Ghorbani ◽  
Amir Ghaemi ◽  
Pegah Rafiee

Abstract Background In recent years, the role of neuroinflammation and oxidative stress in migraine pathogenesis has achieved considerable interest; however, to date findings are equivocal. Thus, the objective of this study was to investigate biomarkers of oxidative stress in episodic and chronic migraineurs (EM and CM patients) and controls. Methods Forty-four patients with EM, 27 individuals with CM and 19 age-sex-matched controls were enrolled. After collecting data on demographic and headache characteristics, blood samples were collected and analyzed to detect serum levels of oxidative stress biomarkers (malondialdehyde (MDA) and nitric oxide (NO)); total antioxidant capacity using Trolox equivalent antioxidant capacity (TEAC) assay; and antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase-1 (GPx-1)). Results Serum levels of CAT and SOD were significantly lower in the CM group than the EM group and controls. However, serum GPx-1 levels of the CM patients were slightly higher than the EM patients and controls (P-value≤0.001). CM patients had lower mean TEAC values than EM patients and controls. In addition, serum levels of NO and MDA were significantly elevated among subjects with CM compared to EM and control individuals (P-value≤0.001). Pearson correlation analysis revealed negative correlations between the number of days of having headaches per month and serum concentrations of the two antioxidant enzymes CAT (r = − 0.60, P-value< 0.001) and SOD (r = − 0.50, P-value< 0.001) as well as TEAC values (r = − 0.61, P-value< 0.001); however, there were positive correlations between headache days and serum GPx-1 levels (r = 0.46, P-value< 0.001), NO (r = 0.62, P-value< 0.001), and MDA (r = 0.64, P-value< 0.001). Conclusion Present findings highlighted that chronic migraineurs had lower total non-enzymatic antioxidant capacity and higher oxidative stress than episodic migraineurs and control individuals. Although more studies are needed to confirm these data, applying novel prophylactic medications or dietary supplements with antioxidant properties could be promising in migraine therapy.


2013 ◽  
Vol 53 ◽  
pp. 350-353 ◽  
Author(s):  
Andrea Acampora ◽  
Sara Croce ◽  
Alberto Assirelli ◽  
Angelo Del Giudice ◽  
Raffaele Spinelli ◽  
...  

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