Antioxidative polyphenols represented by tannins and flavonoids are rich in numerous food sources and traditional natural medicines and currently attracting increased attention in health care and ...food industries because of their multiple biological activities that are favorable to human health. Commemorating the outstanding achievements on tannins by Dr. Takuo Okuda on the occasion of his passing away in December 2016, his colleagues, friends, and worldwide experts of polyphenol research have contributed 18 papers on their recent study to the Special Issue of Molecules. This book is its reprinted form. This covers reviews of structural features, historical usages, and biological activities of unique class of ellagitannins and condensed tannins, and original articles on the most up-to-date findings on the anticancer effect of green tea catechins, the antivirus effect of tannins comparing with the clinically used drugs, the analytical method of ellagitannins using quantitative NMR, the chemical structures of Hydrangea-blue complex (pigment) and condensed tannins in Ephedra sinica and purple prairie clover, and the relationship of condensed tannins in legumes and grape-marc with methane production in the in vitro ruminant system, and others.
This book will be useful to natural product chemists and also to researchers in pharmaceutical and/or food industry.
Tannins, an abundant group of plant secondary compounds, raise interest in different fields of science, owing to their unique chemical characteristics. In chemical ecology, tannins play a crucial ...role in plant defense against pathogens, herbivores, and changing environmental conditions. In the food industry and in medicine, tannins are important because of their proven positive effect on human health and disease treatment. Such wide interests fueled studies on tannin chemistry, especially on their flagship ability to precipitate proteins. In this Review, we expand the basic knowledge on tannin chemistry to the newest insights from the field. We focus especially on tannin reactions with different non‐protein organic N compounds, as well as the complex interactions of tannins with enzymes, resulting in either an increase or decrease in enzyme activity.
Tannins breaking news: Tannin–protein interactions have been studied for more than half a century, owing to their unparalleled characteristics and potential for application in different fields. Although tannins have been studied extensively, the newest discoveries show that tannins interact not only with proteins, but also other organic compounds. Furthermore, the outcome of these interactions depends on tannin concentration. These new insights are of general interest for application in, for example, the medical industry and beverage/food industry.
Plant tannins are known for their anthelmintic and antiparasitic activities and have been increasingly studied to battle the ever-growing problem of anthelmintic resistance. While tannins have been ...shown to exhibit these activities on their own, one approach would be to use them as complementary nutrients alongside commercial anthelmintics. So far, research on the interactions between tannins and anthelmintics is limited, and few studies have reported both synergistic and antagonistic effects depending on the type of tannin and the method used. These interactions could either strengthen or weaken the efficacy of commercial anthelmintics, especially if tannin-rich diets are combined with anthelmintics used as oral drenches. To study these interactions, a series of hydrolysable tannins (HTs) was selected, and their direct interactions with thiabendazole (TBZ) were evaluated by isothermal titration calorimetry (ITC), which allowed the detection of the exothermic interaction but also the roles and significances of different structural features of HTs in these interactions. Our results show that HTs can have a direct interaction with the benzimidazole anthelmintic TBZ and that the interaction is strengthened by increasing the number of free galloyl groups and the overall molecular flexibility of HTs.
Chestnut tannin: New use, research and bioeconomy Ciriminna, Rosaria; Meneguzzo, Francesco; Petri, Giovanna Li ...
Journal of Bioresources and Bioproducts,
August 2024, Letnik:
9, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Chestnut tannin, extracted from the bark or wood of chestnut trees, possesses unique properties that make it valuable in various industries. It serves as a natural source of tannins, which are widely ...used in the production of leather, textiles, and wood preservation. As research continues to explore its potential applications, chestnut tannin remains a promising resource with diverse industrial uses. Highlighting new use, research and bioeconomy aspects, this study provides a unified perspective on chestnut tannin. New advanced applications will likely emerge shortly.
This study introduces a new type of biocomposite material, which is created by combining Carbon xerogel (CX) which formed from Tannin, as biopolymer, extracted from banana waste, together with ...several metal oxides (Fe3O4, CuO, and MgO). This biocomposite is developed to improve the adsorption of Cobalt (II) by a combination of experimental and theoretical methods. The interaction between the components of the bio composite was confirmed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. Carbon xerogel/Fe3O4 composite (CX/Fe) material is arranged in a layered structure, with each layer stacked on top of the other. Furthermore, the surface roughness of the CX/Fe material after Co2+ adsorption demonstrated the improved dispersion properties of CX, as well as the weak electrostatic contact between CX and Co2+.Furthermore, thorough examinations were conducted to assess the efficacy of a bio-adsorbent in eliminating cobalt ions from wastewater across different operational circumstances. The findings indicated that carbon xerogels (CX/Fe, CX/Mg, and CX/Cu) exhibited remarkable maximum removal efficiency of around 99.66 %, 98 %, and 97.96 %, respectively, and the adsorption capacity using CX/Fe was 9.994 mg.g-1, CX/Mg was 9.9637 mg.g-1 and CX/Cu was 9.96297 mg.g-1 over a 30-min timeframe. Monte Carlo simulations showed that the examination of molecular structures involving Co2+ on CX/Fe surfaces suggests that chemical forces may have a significant influence on the adsorption process, which is consistent with the experimental findings.
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•Green carbon xerogel with different metal oxides composites for cobalt adsorption.•CX/Fe appeared as fibrous stacked Layered which facilitates the adsorption process.•Gwyddion software confirmed the mechanism of adsorption through Carbon xerogel.•Co2+adsorption on CX/Fe was a chemical reaction verified practical and theoretical.
High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and ...mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.
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•Inulin with a polymerization degree of 2-60 enhanced the solubility of high-polymerization persimmon tannin.•Inulin enhanced the efficacy of persimmon tannin in enhancing health in HFD-fed mice.
The shelf life of fresh fish and meat transported over long distances could be extended by using plant-based extracts to control spoilage bacteria. The goals of the present study were to identify ...plant-based extracts that effectively suppress the main spoilage bacteria of chilled fish and lamb and to assess their antioxidant capacity. The phenolic compounds in wood-based tannins and extracts isolated from byproducts of the fruit processing industry were identified and/or quantified. The total phenol content, but not the flavonoid to total phenol ratio, was strongly associated with higher antibacterial activity against several fish and lamb spoilage bacteria in zone of inhibition and minimum inhibitory concentration assays as well as greater antioxidant capacity in the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical assay. The most promising compounds in both cases, and thus good candidates for antibacterial packaging or antioxidant dietary supplements, were mango seed extract and tannic acid containing mostly polygalloyl glucose type phenols.
In red winemaking, the extractability of condensed tannins (CT) can vary considerably even under identical fermentation conditions, and several explanations for this phenomenon have been proposed. ...Recent work has demonstrated that grape pathogenesis-related proteins (PRPs) may limit retention of CT added to finished wines, but their relevance to CT extractability has not been evaluated. In this work, Vitis vinifera and interspecific hybrids (Vitis ssp.) from both hot and cool climates were vinified under small-scale, controlled conditions. The final CT concentration in wine was well modeled from initial grape tannin and juice protein concentrations using the Freundlich equation (r
= 0.686). In follow-up experiments, separation and pretreatment of juice by bentonite, heating, freezing, or exogenous tannin addition reduced protein concentrations in juices from two grape varieties. The bentonite treatment also led to greater wine CT for one of the varieties, indicating that prefermentation removal of grape protein may be a viable approach to increasing wine CT.
A precipitation assay is presented that enables tannin measurement in matrices of red wine, 50% ethanol grape extract and aqueous tannin solutions. By exploiting the polysaccharide polymer methyl ...cellulose to precipitate tannins, the absorbance of phenolics at 280 nm before and after tannin precipitation (subtractive approach) can be obtained, thus enabling selective measurement of tannin only. This methyl cellulose precipitable (MCP) tannin assay allows complete precipitation of tannin from red wine and from grape homogenate extracts. The subtractive assay is both simple and robust, selective for condensed tannins and does not suffer interference from other 280 nm‐absorbing phenolics such as anthocyanins or catechins. Matrix effects have only minimal impact on the assay performance and validation parameters indicate a robust performance. There was good correlation between tannin measured by reverse‐phase HPLC and the MCP tannin assay for 121 Australian red wines (r= 0.74) and also 54 grape extracts (r= 0.79). We envisage that the technical simplicity of this tannin assay will enable widespread research and field applications. In addition, an alternative format that requires re‐solubilisation of the tannin‐polymer pellet in acetonitrile is reported, which is particularly suitable for measurement of smaller tannin concentrations. Notwithstanding that option, technical requirements of the re‐solubilisation step lead us to suggest that the subtractive format would be simple for adoption by wine industry practitioners.
Non-covalent and covalent associations of polyphenols with food macromolecules are two of the most fundamental factors affecting the quality of polyphenol-rich food products. This review therefore ...describes the biochemical bases of associations between polyphenols and macromolecules, that is, proteins and polysaccharides. Our intent is to provide a level of understanding that can be used to underpin future research directions. This will help to resolve existing issues that limit organoleptic and nutritional qualities of polyphenol-rich foods and drinks. It will also allow a better understanding of the functional consequences of these interactions on food/biological systems.The methods used to study non-covalent and covalent interactions are described, and the limiting factors of each method are emphasized. The biochemical mechanisms of interaction between polyphenols and macromolecules are also described. In processed food, non-covalent polyphenol/macromolecule interactions are largely due to weak associations, and result from a combination of hydrogen bonds and hydrophobic interactions. The biochemical mechanisms for covalent interactions involve oxidation of phenolic compounds, whether enzymatically mediated or not, with the formation of o-quinones or o-semi-quinones, or the cleavage of procyanidin interflavanic bonds in acid medium with the formation of carbocations. The effects of factors such as polyphenol structure, macromolecule structure, relative concentrations of both polyphenol and macromolecule, solvent composition, ionic strength, temperature, and pH are discussed.
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