hydroxyl radical
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2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shayma T.G. Al-Sahlany ◽  
Alaa K. Niamah

Purpose The purpose of this study was to assess the bacterial viability, antioxidative activity, antimutagenicity and sensory evaluation of fermented onion types by using probiotic starters after fermentation at 37 °C for 24 hours and storage in the refrigerator for 28 days. Design/methodology/approach For onion fermentation, Lactobacillus acidophilus (LA-5), Bifidobacterium bifidum (BB-12), and Streptococcus thermophilus (ST) were utilised. This research was conducted on three types of onion: white onion, red onion and scallion. With a 5% brine solution, the onions were sliced into 3-5 cm long and 1-2 cm wide slices. The process of fermentation was achieved by adding 2% (108 CFU/ gm) of fresh probiotic starter and incubating it for 24 hours at 37 °C. The fermented onion samples were kept in the refrigerator for 28 days. After fermentation and storage, the pH and total acidity were estimated, the vitality of probiotic bacteria was evaluated in samples of the onion species. The Gas chromatography-mass spectrometry (GC-MS) technique was used to identify the bioactive components in fermented onion types. The antioxidant activity of fermented onions was measured using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity assay and the hydroxyl radical scavenging activity test. The Ames test was used to detect the antimutagenicity of fermented onion samples. Findings After fermentation, the fermented scallion (p = 0.036) has the highest vitality of all the starter bacteria species. The fermentation of onion types produced a pH of between 4.1–4.7 and 0.19–0.23% total acidity, which is in the range of reduced 3.1–3.5 pH values and 0.42–0.63% total acidity after 28 days. The viability of Lactobacillus acidophilus and Bifidobacterium bifidum in fermented scallions was Log. 7.79 and 7.57 CFU/gm. The GC-MS technique found 14 bioactive compounds in fermented white onions and 13 compounds in fermented white onions, with 15 compounds in scallion fermentation. The majority of these bioactive compounds are strong antioxidants. The antioxidant properties of fermented scallion significantly increased after 28 days of storage time, showing an inhibitory effect on the DPPH assay (p = 0.02) and the scavenging activity of the hydroxyl radical assay (p = 0.01). Sensory evaluation tests revealed that the fermented scallion was a suitable product in terms of appearance, aroma and overall acceptability. Originality/value Commercially accessible probiotic foods account for a sizable portion of the consumer market. Furthermore, as consumer interest in healthy eating grows, so does demand for plant-based goods. All onion types fermented with probiotic bacteria have many chemical compounds that have both antioxidant and carcinogenic activity. The fermented scallion onion sample was significantly superior to the rest of the other types of onions.


Foods ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Kun Dai ◽  
Yingying Wei ◽  
Shu Jiang ◽  
Feng Xu ◽  
Hongfei Wang ◽  
...  

Thinned peach polyphenols (TPPs) were extracted by ultrasonic disruption and purified using macroporous resin. Optimized extraction conditions resulted in a TPPs yield of 1.59 ± 0.02 mg GAE/g FW, and optimized purification conditions resulted in a purity of 43.86% with NKA-9 resin. TPPs composition was analyzed by UPLC-ESI-QTOF-MS/MS; chlorogenic acid, catechin, and neochlorogenic acid were the most abundant compounds in thinned peaches. Purified TPPs exhibited scavenging activity on DPPH, ABTS, hydroxyl radical, and FRAP. TPPs inhibited α-amylase and α-glucosidase by competitive and noncompetitive reversible inhibition, respectively. TPPs also exhibited a higher binding capacity for bile acids than cholestyramine. In summary, TPPs from thinned peaches are potentially valuable because of their high antioxidant, hypoglycemic, and hypolipidemic capacities, and present a new incentive for the comprehensive utilization of thinned peach fruit.


2021 ◽  
Author(s):  
R. Masmoudi ◽  
S. Khettaf ◽  
A. Soltani ◽  
A. Dibi ◽  
L. Messaadia ◽  
...  

Abstract In this work, density functional theory is used to study the local reactivity of cephalexin (CLX) to radical attack and explain the mechanism of the reaction between CLX and hydroxyl radical attack leading to degradation byproducts. The reaction between •OH and CLX is supposed to lead to either an addition of a hydroxyl radical or an abstraction of a hydrogen. The results showed that the affinity of cephalexin for addition reactions increases as it passes from the gas to the aqueous phase and decreases as it passes from the neutral to the ionized form. Thermodynamic data confirmed that OH addition radicals (Radd) are thermodynamically favored over H abstraction radicals (Rabs). The ecotoxicity assessments of CLX and its byproducts are estimated from the acute toxicities toward green algae, Daphnia and fish. The formation of byproducts is safe for aquatic organisms, and only one byproduct is harmful to Daphnia.


2021 ◽  
Author(s):  
Ashlyn M Koval ◽  
Harley McAlexander ◽  
Christa M. Woodley ◽  
Manoj K. Shukla

Abstract Arsenic is an environmentally ubiquitous health hazard due to its toxicity combined with its natural abundance and heavy industrial applications. Due to its role in cardiovascular disease, neurotoxicity, and various cancers, it is important to understand environmental fate of arsenic-containing compounds to take steps towards remediation. Sodium arsenite (NaAsO2) is one such compound that has been used worldwide as an herbicide, rodenticide, and insecticide. It is also toxic by ingestion, inhalation, and skin absorption. In aqueous environments arsenite (As(III))-containing compounds can be oxidized to the less-toxic arsenate (As(V)) form. We have investigated the oxidation of sodium arsenite in water solution at the density functional theory level using the Minnesota 06 hybrid (M06-2X) functional and Pople basis sets (6-31G(d,p) and 6-311G(d,p)) with polarizable continuum model (PCM) solvation approach. Our computational results indicate that the oxidation mechanism of NaAsO2 by hydroxyl radical proceeds via sequential addition reactions where sodium arsenite (III) converts to sodium arsenate (V) via an arsenic (IV) intermediate.


Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Anna Bojanowska-Czajka ◽  
Marta Pyszynska ◽  
Agnieszka Majkowska-Pilip ◽  
Kamil Wawrowicz

Gamma radiation was applied to degradation selected antidepressants in ultrapure water and surface water. Additionally, the influence of typical radical scavengers like carbonate, nitrate and humic acid was determined. The cytotoxicity towards liver cells HepG2 and colon cells Caco2 were measured during the radiation process. It was found that radiation technology, specifically ionizing radiation, can achieve satisfactory degradation efficiency with both SER and CIT. It was shown that the process of decomposition of the tested antidepressants with the highest efficiency occurs in the reaction with the hydroxyl radical.


Foods ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Tingting Han ◽  
Yang Huang ◽  
Chong Sun ◽  
Daoying Wang ◽  
Weimin Xu

In this paper, carboxylated carbon nitride nanoparticles (carboxylated-g-C3N4 NPs) were prepared through a one-step molten salts method. The synthesized material was characterized by transmission electron microscope (TEM), Fourier transform-infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS), etc. An electrochemical sensor based on single-stranded oligonucleotide/carboxylated-g-C3N4/chitosan/glassy carbon electrode (ssDNA/carboxylated-g-C3N4/chitosan/GCE) was constructed for determination of the hydroxyl radical (•OH), and methylene blue (MB) was used as a signal molecule. The sensor showed a suitable electrochemical response toward •OH from 4.06 to 122.79 fM with a detection limit of 1.35 fM. The selectivity, reproducibility, and stability were also presented. Application of the sensor to real meat samples (i.e., pork, chicken, shrimp, and sausage) was performed, and the results indicated the proposed method could be used to detect •OH in practical samples. The proposed sensor holds a great promise to be applied in the fields of food safety.


2021 ◽  
Vol 23 (12) ◽  
pp. 339-360
Author(s):  
Suresh kumar Tirupur Venkatachalam ◽  
◽  
SenthilKumar Palanisamy ◽  
Sudhagar Babu ◽  
Ranjithkumar Rajamani ◽  
...  

Aim: The study reports the in vitro free radical scavenging and α-amylase and α-glucosidase inhibition activities of aqueous extract of seagrass Cymodocea serrulata from Gulf of Mannar, Southeast Asia. Methods: The free radical scavenging activity was evaluated by DPPH, Superoxide, Nitric oxide and Hydroxyl radical scavenging assays and α-amylase, α-glucosidase enzyme inhibitory activity. The C. serrulata showed effective DPPH radical scavenging activity of 69.45 μg/mL, Superoxide radical scavenging activity of 91.08.5 ± 0.02%, Nitric oxide radical scavenging activity of 86.89 ± 0.03% and Hydroxyl radical scavenging activity of 81.09 ± 0.3 % at a concentration of 5 μg/mL respectively. It also showed significant inhibitory activity against α- amylase with an IC50 value of 3.0 ± 0.04 (μg/ml) and the α-glucosidase inhibitory activity with an IC50 value of 3.7 ± 1.01 (μg/ml) at concentrations of 1-5 μg/mL. Conclusion: Cymodocea serrulata was found to be a potent free radical scavenger and inhibitor of α-amylase and α-glucosidase enzymes.


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