This reprint includes papers from different research fields, reflecting the sectional talks presented at the 10th edition of the Scientific Conference of the Doctoral Schools of “Dunărea de Jos” ...University of Galaţi, which took place in June 2022. The objective of the 2022 Conference was to bring together perspectives and challenges in doctoral research in a common forum and to provide a platform enabling doctoral researchers to meet and share state-of-the-art developments in their fields. It comprises 13 papers presented at the conference from several fields, including mechanical and industrial engineering, food science and biotechnology, electrical/electronic engineering, systems engineering and information technologies, chemistry, electrochemistry, and economic models and strategies.
Background
Red onion husk, a readily available agricultural waste material, contains diverse bioactive compounds with potential health benefits. This study aimed to assess the safety and therapeutic ...potential of red onion husk extract in managing manic-like symptoms and associated neurochemical dysfunctions.
Methods
Acute and repeated oral dose studies were conducted in mice and rats to evaluate the safety profile of the extract. FT-IR analysis identified functional groups in the extract, while GC-MS analysis identified specific bioactive compounds in the flavonoid-rich fraction. A ketamine-induced manic behaviour model in Wistar rats was employed to assess the extract’s efficacy in attenuating manic-like symptoms. Behavioural and neurochemical analyses were performed to further investigate the extract’s effects.
Results
The extract demonstrated a favourable safety profile in both acute and repeated dose studies. FT-IR analysis revealed a complex mixture of organic compounds, including hydroxyl groups, alkynes/nitriles, aromatic and non-aromatic C = C bonds, amines, and polysaccharides. GC-MS analysis identified 17 bioactive compounds, including five-methyl-2-phenylindolizine, methadone N-oxide, and 3-phenylthiane, S-oxide. Ketamine administration significantly increased oxidative stress markers, TBARS, and suppressed antioxidant enzyme activities (SOD, GPx, CAT) in both the cerebral cortex and hippocampus, alongside elevated acetylcholinesterase (AchE) activity, indicating enhanced neuronal excitability. Pre-treatment with FRF (25 mg/kg) effectively mitigated ketamine-induced oxidative stress, as evidenced by reduced TBARS levels and partially restored SOD and GPx activities. Interestingly, FRF significantly increased CAT activity (
p
< 0.001), potentially suggesting an additional compensatory mechanism. Notably, FRF pre-treatment also counteracted ketamine-upregulated AchE activity, offering neuroprotection against heightened neuronal excitability.
Conclusion
Red onion husk extract exhibits a favourable safety profile and exerts potent antioxidant and neuroprotective effects, possibly through modulating Nrf2 signalling pathways. Its ability to counteract ketamine-induced oxidative stress and neuronal hyperactivity highlights its potential as a complementary therapeutic strategy for managing manic episodes in bipolar disorder. Further research is warranted to elucidate the precise molecular mechanisms underlying FRF’s action and explore its clinical efficacy in human studies.
Introduction: Tinea pedis is a dermatophyte infection of human feet, especially between the fingers and soles of the feet. Tinea pedis is caused by a fungal infection of Trichophyton rubrum. Red ...onion is one of the spices that has been widely known by the community and used as a traditional medicine in the prevention of fungus. The objective of this research was to determine the antifungal activity of gel produced from an extract of red onion on T. rubrum. Materials and Methods: The gel was formulated with various concentration of red onion, FI with a concentration of extract (5%), F2 (7.5%). and F3 (12.5%). Each formula tested the physical characteristics and antifungal activity toward T. rubrum. The antifungal activity was determined by the agar well-diffusion method using Saboround Dextrose Agar plates. Furthermore, the antifungal activities were assessed by the presence or absence of inhibition zones after the plates were incubated at 28oC for 7 days. Results: F3 has the greatest inhibitory power than F1 and F2 (P < 0.05). Then, F3 has the same inhibitory power as a positive control (P > 0.05). Discussion: All gel understudy at various concentrations of red onion was formulated in gel-exhibited antifungal activity. Antifungal activity of red onion occurred because it contained allicin. Therefore, the researchers can use these gels as a natural antifungal in the healing of tinea pedis caused by T. rubrum. Conclusion: The gel from an extract of red onion showed significant antifungal activity against T. rubrum.
Pressurized Hot Water Extraction (PHWE) is a quick, efficient and environmentally friendly technique for extractions. However, when using PHWE to extract thermally unstable analytes, extraction and ...degradation effects occur at the same time, and thereby compete. At first, the extraction effect dominates, but degradation effects soon take over. In this paper, extraction and degradation
rates of anthocyanins from red onion
were studied with experiments in a static batch reactor at 110
°C. A
total extraction curve was calculated with data from the actual extraction and degradation curves, showing that more anthocyanins, 21–36% depending on the species, could be extracted if no degradation occurred, but then longer extraction times would be required than those needed to reach the peak level in the apparent extraction curves. The results give information about the different kinetic processes competing during an extraction procedure.
Red onion is a popular ingredient in many Thai dishes and has recently been promoted for commercial cultivation. In this study, inulin-fructooligosaccharides (inulin-FOSs) were extracted from red ...onions in a simplified extraction method. The extract contained 24.00 ± 0.38 g/L free glucose, fructose and sucrose, while the level of FOSs was recorded at 74.0 ± 2.80 g/L with a degree of polymerization of 4.1. The extract was resistant to simulated gastrointestinal conditions, while selectively promoting probiotic lactobacilli. These outcomes resulted in inhibitory effects against various pathogenic bacteria. The in vitro batch culture fermentation of the extract by natural mixed culture indicated that an unknown sugar identified as neokestose was more rapidly fermented than 1-kestose and other longer-chain inulin-FOSs. Notably, neokestose selectively encouraged a bifidogenic effect, specifically in terms of the growth of Bifidobacteirum breve, which is an infant-type probiotic bacterium. This is the first report to state that neokestose could selectively enhance the bifidogenic effect. In summary, inulin-FOSs extract should be recognized as a multifunctional ingredient that can offer benefits in food and pharmaceutical applications.
Cotton fabrics were dyed using the extract from red onion skins. The differences between red and brown onion skin and the differences between cotton and silk were investigated. The colors of the ...fabrics dyed with and without six types of mordants, including Mg2+, Al3+, Ca2+, Ti4+, Fe3+ and Cu2+, were measured by a spectrophotometer and expressed according to the CIELAB color system and ΔE* value. The red onion skin contained quercetin, which is also found in brown onion skin, in addition to malvidin-3-arabinoside of anthocyanins. The cotton was dyed a light color at a temperature of more than 80℃. The color of the dyed cotton did not change after an immersion period longer than 8 h. No significant damage or changes in the structure of the fibers as a result of the dyeing were detected. The color fastness to light and to washing (color change) of the fabrics was enhanced by mordant treatment of some metal ions.
In an effort to find a new whitening agent, we have found that the methanol extract of the dried skin of
Allium cepa showed inhibition of melanin formation. Bioassay-guided fractionation led to the ...isolation of quercetin (
1) and quercetin 4’-
O-β-glucoside (
3) from
A. cepa as the inhibitors of melanin formation in B16 melanoma cells with IC
50 values of 26.5 and 131
μM, respectively. In addition, we evaluated the effect of some quercetin derivatives, such as isoquercitrin (
2), quercetin 3,4’-
O-diglucoside (
4), rutin (
5) and hyperin (
6) on B16 melanoma cells. These quercetin derivatives did not show any inhibition of melanin formation. Furthermore, the ORAC values of compounds
1–
6 were 7.64, 8.65, 4.82, 4.32, 8.17 and 9.34
μmol trolox equivalents/μmol, respectively. Dried skin of red onion showed inhibitory activity against melanin formation in B16 melanoma cells, as well as antioxidant properties.
The objective of this study was to encapsulate anthocyanins from red onion skins into different biopolymeric matrices as a way to develop powders with multifunctional activities. Two different ...variants of powders were obtained using a combination of gelation and freeze-drying techniques and characterized by encapsulation efficiency, antioxidant activity, phytochemical content, and color. Stability during storage and the bioavailability of anthocyanins in the in vitro simulated digestion were also examined. Powder V2, with a higher concentration of polysaccharides than V1, allowed a better encapsulation efficiency (90.53 ± 0.29%) and good stability during storage. Both variants had a high content of phytochemicals and antioxidant activity. In vitro investigations proved that an increased polysaccharides concentration offers the best protection for anthocyanins. Thus, a controlled release of the anthocyanins in the intestinal medium was achieved. The powder with the highest encapsulation efficiency was added to crackers, followed by phytochemical characterization to assess its potential added value. The addition of the micro-particles improved the functional characteristics such as antioxidant activity, showing its suitability for the development of bakery products. The attained results may bring implicit benefits to consumers, who can benefit from improved bioactive concentrations in foodstuffs, with significant health benefits.
UV-initiated green synthesis of metal nanoparticles by using plant extracts as photoreducing agents is of particular interest since it is an environmentally friendly, easy-to-maintain, and ...cost-effective method. Plant molecules that act as reducing agents are assembled in a highly controlled way which makes them suitable for metal nanoparticle synthesis. Depending on the plant species, their application for green synthesis of metal nanoparticles for diverse applications may contribute to the mediation/reduction in organic waste amounts, thus enabling the implementation of the circular economy concept. In this work, UV-initiated green synthesis of Ag nanoparticles in hydrogels and hydrogel's thin films containing gelatin (matrix), red onion peel extract of different concentrations, water, and a small amount of 1 M AgNO
have been investigated and characterized using UV-Vis spectroscopy, SEM and EDS analysis, XRD technique, performing swelling experiments and antimicrobial tests using bacteria (
,
,
), yeasts (
,
) and microscopic fungi (
,
). It was found that the antimicrobial effectiveness of the silver-enriched red onion peel extract-gelatin films was higher at lower AgNO
concentrations as compared to those usually used in the commercially available antimicrobial products. The enhancement of the antimicrobial effectiveness was analyzed and discussed, assuming the synergy between photoreducing agent (red onion peel extract) and silver nitrate (AgNO
) in the initial gel solutions leading to the intensification of Ag nanoparticles production.
PDF
