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•Deep Eutectic Solvents based on menthol, thymol and organic acids were prepared.•The studied solvents present high extraction capability for phenolic compounds.•The best extraction ...results were obtained using menthol based mixtures.•The extraction efficiency follows the sequence: 2-chlorophenol >o-cresol >phenol.
Phenolic compounds are present both in nature as components of fruits, coffee or tea, and in wastewaters of many different industries. The world organization WHO, list some of these phenolic compounds as priority pollutants due to their toxicity, so it is necessary to remove them, to a concentration below the legal limit (1 mg·L−1) before wastewater discharge. In this work, six new solvents, Deep Eutectic Solvents (DES) based on organic acids (dodecanoic acid, decanoic acid, octanoic acid) and menthol or thymol, were studied as extraction solvents for these pollutant compounds. Their physical properties (density, viscosity, refractive index and speed of sound) were measured, as well as their capability to remove phenolic compounds (phenol, o-cresol and 2-chlorophenol) from water using liquid-liquid extraction. The experimental data were compared with other results obtained for the extraction phenolic compounds from water using Ionic Liquids. The results obtained show that the use of these new solvents provide a good extraction method for phenolic compounds present in wastewaters. The best results were obtained for menthol based DES to extract o-cresol and 2-chlorophenol, getting extraction efficiencies upper than 85% for all initial concentration of phenolic compound.
Qin et al. have proposed an ecological and efficient method of extraction polyphenols from the leaves of Ligustrum robustum using eutectic solvents, assisted by ultrasounds. The authors tested a ...number of solvents, optimized the extraction parameters and explored the extraction mechanism. According to the results of biological activity experiments of the prepared Ligustrum robustum leaves extracts, they seem promising for practical applications. The issue which is disputable is the identification of the phenolic compounds by using electrospray ionization mass spectrometry, as described in details in this comment.
Phenolic compounds (PCs) are diverse in nature and undergo complex migration and transformations in the environment, making it challenging to use techniques such as chromatography and other ...traditional methods to determine the concentration of PCs by separation, individual monitoring and subsequent addition. To address this issue, a facile and on-site strategy was developed to measure the concentration of PCs using a novel nanozyme with polyphenol oxidase-like activity. First, the nanozyme was designed by coordinating the asymmetric ligand nicotinic acid with copper to mimic the structure of mononuclear and trinuclear copper clusters of natural laccases. Subsequently, by introducing 2-mercaptonicotinic acid to regulate the valence state of copper, the composite nanozyme CuNA10S was obtained with significantly enhanced activity. Interestingly, CuNA10S was shown to have a broad substrate spectrum capable of catalyzing common PCs. Building upon the superior performance of this nanozyme, a method was developed to determine the concentration of PCs. To enable rapid on-site sensing, we designed and prepared CuNA10S-based test strips and developed a tailored smartphone sensing platform. Using paper strip sensors combined with a smartphone sensing platform with RGB streamlined the sensing process, facilitating rapid on-site analysis of PCs within a range of 0–100 μM. Our method offers a solution for the quick screening of phenolic wastewater at contaminated sites, allowing sensitive and quick monitoring of PCs without the need for standard samples. This significantly simplifies the monitoring procedure compared to more cumbersome large-scale instrumental methods.
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•A novel nanozyme mimicking the laccase structure.•A facile and on-site sensing strategy for phenolic compounds.•The test paper strip-based smartphone-assisted sensing platform.
Commercial buckwheat flours were investigated for their antioxidant activities
, free, and bound phenolic compositions using spectrophotometer, LC–ESI-IT-MS, and LC–ESI-Q-TOF-MS. Farinetta flour ...contained the highest free and bound phenolic contents, followed by Supreme, whole buckwheat, and Fancy flour, respectively. The 50% ethanol extraction achieved significantly higher free phenolic content compared with water and absolute alcohol. The absolute ethanol extraction contained considerable more bound phenolic and flavonoid compounds. A high extraction temperature increased the phenolic contents. The optimal solvent to solids ratio was 50:1, and the optimal extraction time was 5
h for flavonoids. The spectral method was reproducible for analysing the total flavonoid contents. The LC–ESI-Q-TOF-MS studies on whole buckwheat flour showed that p-coumaric and gallic acids were found in the bound phenolics along with isoquercitrin but were not present in the free phenolic compounds. The free flavonol-glycosides were found in whole buckwheat flour but not in any other buckwheat flours.
Summary
Mayonnaise is an oil in water emulsion of egg, oil and an acid, worldwide consumed. The major challenges of the mayonnaise industry include searching for an alternative protein source. This ...study evaluates an alternative protein source, yeast protein extract (YPE), to replace egg in the mayonnaise model. Furthermore, the natural ability of phenolic compounds (PCs) to bind to proteins was studied to enhance the emulsifying capacity of YPE. The mayonnaise‐like emulsions were characterised according to their rheology, texture and colour profile. There were no differences in rheological parameters between the YPE emulsion (G' at 1 Hz 785 ± 15 Pa) and onion powder emulsion (G' at 1 Hz 785 ± 15 Pa) compared with the commercial mayonnaise (CC, G' at 1 Hz 747 ± 16 Pa). In general, the emulsions obtained with YPE and YPE‐PCs were found to have similar viscoelastic and viscosity properties to the CC. In terms of texture profile (firmness) the blueberry powder (0.574 ± 0.036 N), grape seed extract (0.497 ± 0.061 N) or wine extract (0.626 ± 0.128 N) YPE emulsions were equal to CC (0.561 ± 0.031 N). As a result, some of the mayonnaise‐like emulsions developed could be alternatives to CC regarding physical–chemical properties.
The main goal of this study is to design a new vegan clean‐label mayonnaise‐like emulsion using yeast protein extracts (YPE) as a true substitute for the egg in traditional mayonnaise. Different sources of phenolic compounds were tested as stabilizer of this novel food. Namely, onion, grape and blueberry extracted were used. The rheology, texture and colour proprieties were assayed.
In this review, the concept of phenolic antioxidants, mechanisms of action, and applications have been reviewed. Phenolic compounds (PCs) acts as an antioxidant by reacting with a variety of free ...radicals. The mechanism of antioxidant actions involved either by hydrogen atom transfer, transfer of a single electron, sequential proton loss electron transfer, and chelation of transition metals. In foods, the PCs act as antioxidants which are measured with several in vitro spectroscopic methods. The PCs have been found in milk and a wide range of dairy products with sole purposes of color, taste, storage stability, and quality enhancement. The role of PCs in three types of food additives, that is, antimicrobial, antioxidant, and flavoring agents have been critically reviewed. The literature revealed that PCs present in a variety of foods possess several health benefits such as antibacterial, antihyperlipidemic, anticancer, antioxidants, cardioprotective, neuroprotective, and antidiabetic properties.
Practical applications
Phenolic compounds are strong antioxidants and are safer than synthetic antioxidants. The wide occurrence in plant foods warranted continuous review applications. This review, therefore, presented an updated comprehensive overview of the concept, mechanism, and applications of phenolic antioxidants in foods.
An updated comprehensive overview of the concept and mechanism of phenolic antioxidants in foods has been presented. The applications of phenolic antioxidants as antioxidants in foods, applications in dairy products, as food additives, flavoring agents, and health applications reported in the latest literature have been reviewed.
The edible flowers are widely used, but there is still a lot to be done in relation to its bioactive potential and its correlation with the presence of phenolic compounds. The aim of this study was ...determined the individual phenolic profile in the hydromethanolic extracts and infusion preparations of four different flower samples (Dahlia mignon, Rosa damascena ‘Alexandria’ and R. gallica ‘Francesa’ draft in R. canina, Calendula officinalis L., and Centaurea cyanus L.) and their bioactive potential (antioxidant, antiproliferative, and antibacterial capacity). All the studied flowers presented different profiles regarding their phenolic composition and revealed biological potential. The bioactive potential of the studied flowers was moderate, the hydromethanolic extracts of rose petals showed the best results for antioxidant and antibacterial assays, while the antiproliferative properties were only present in some of the tested cell lines, for the hydromethanolic extracts, in which dahlia and rose showed the best results. These results demonstrate that edible flowers can be used as a source of phenolic compounds with bioactive potential, which can be applied in the food sector, as foods and as sources natural ingredients.
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•Edible flowers are a source of phenolic compounds.•Phenolic compounds present in edible flowers are responsible for the bioactivities.•Edible flowers showed antioxidant, antiproliferative, and antibacterial potential.•Rose hydromethanolic extracts showed the best antioxidant and antibacterial results.•Dahlia hydromethanolic extracts showed the highest antiproliferative properties.
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•Organic coffee husks demonstrated considerable post-digestion antioxidant potential in vitro.•Coffee husks enhance cell viability, inhibit ROS.•Caco-2 cell oxidation was attenuated ...upon exposure to organic coffee husk extract.•In vitro colonic fermentation of coffee husks positively impacts microbiota in diabetes.•Organic Coffee Husk presence positively correlated with phenolic release.
Coffee husks are the main by-product of the coffee industry and have been traditionally discarded in the environment or used as fertilizers. However, recent studies have shown that coffee husks have bioactive compounds, such as phenolics and fiber-bound macro antioxidants, offering a range of potential health benefits. This study evaluated the antioxidant capacity, cytoprotective/cytotoxic properties, and stimulatory effects on the relative abundance of selected intestinal bacterial populations of individuals with diabetes of organic coffee husks. Organic coffee husk had good antioxidant capacity, maintained under simulated gastric conditions, with more than 50% of antioxidant capacity remaining. Organic coffee husk exerted cytoprotective properties in Caco-2 cells, indicating that cellular functions were not disturbed, besides not inducing oxidation. Overall, organic coffee husk promoted positive effects on the abundance of distinct intestinal bacterial groups of individuals with diabetes during in vitro colonic fermentation, with a higher relative abundance of Bifidobacterium spp., indicating the availability of components able to reach the colon to be fermented by intestinal microbiota. Organic coffee husk could be a circular material to develop new safe and pesticide-free functional ingredients with antioxidant and potential beneficial effects on human intestinal microbiota.
Sugars play important roles as both nutrients and regulatory molecules throughout plant life. Sugar metabolism and signalling function in an intricate network with numerous hormones and reactive ...oxygen species (ROS) production, signalling and scavenging systems. Although hexokinase is well known to fulfil a crucial role in glucose sensing processes, a scenario is emerging in which the catalytic activity of mitochondria-associated hexokinase regulates glucose-6-phosphate and ROS levels, stimulating antioxidant defence mechanisms and the synthesis of phenolic compounds. As a new concept, it can be hypothesized that the synergistic interaction of sugars (or sugar-like compounds) and phenolic compounds forms part of an integrated redox system, quenching ROS and contributing to stress tolerance, especially in tissues or organelles with high soluble sugar concentrations.
Lignin is widely available in biomass sources, and the aromatic structure can justify its use as a precursor or platform for obtaining value-added compounds. However, lignin is considered a low-price ...by-product or low-value fuel for energy recovery in the pulping industries. Therefore, the development of technologies and methodologies that promote the valorization and efficient utilization of this biopolymer becomes an essential aspect of biobased processes, especially in biorefineries. This review shows the opportunity to target lignin as a marketable by-product for value-added chemicals through thermochemical, chemical, and biochemical pathways, with or without the absence of catalysts. Likewise, the valorization of lignin includes emerging technologies to produce carbon and polymer materials. This work also emphasizes the description of technical, economic, and environmental aspects that would affect lignin in different biorefinery stages. Therefore, a discussion based on current studies and evaluations of lignin valorization processes is considered. Finally, a preliminary techno-economic and environmental assessment of a wood-based biorefinery was performed as an example to better understand the importance of lignin as a platform product in biorefineries. It includes the processing scale analysis over ten years of the project lifetime. The review established the importance of lignin valorization to increase biorefineries efficiency and sustainability.
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•Lignin depolymerization through thermal and bio-chemical routes have been discussed.•Emerging technologies for lignin-based materials are an alternative in the industry.•Efforts to define the sustainability of lignin-based biorefineries are required.•Lignin oxidation shows an economically feasible route in wood-based biorefineries.
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