Exhausted Woods from Tannin Extraction as an Unexplored Waste Biomass: Evaluation of the Antioxidant and Pollutant Adsorption Properties and Activating Effects of Hydrolytic Treatments

Plant-based ink properties and storage stability for inkjet printing

In this sustainability-oriented research, the properties of plant-based inks were evaluated denoting the viscosity range of 8.5 to 10 cP, the relative density of 1.06, conductivity value of 2.51 mS/cm, and the surface tension of 60 mN/m and pH of 4.9 to be most effective for inkjet printing. The changes in these properties to the one-month storage phase are detailed as determined with attenuated total reflectance - Fourier transform infrared spectroscopy, viscometer, and tensiometer. The varied colours of plant-based inks were stable to storage time except for the blue colour ink made from bio indigo herb that displayed agal-like sediments. After the storage phase, the plant-based inks exhibited anti-thixotropic viscosity except for yellow colour plant-based ink demonstrating thixotropic behaviour. High conductivity values of 18.5 and 15.6 mS/Cm were noted for blue and black colour plant-based inks, indicating their potential for constituting conducting inks; however, the conductivity values dropped to 7.5 and 9.5, respectively, after 1 month. The pH and surface tension were found steady during the storage period. The study of the life cycle analysis of plant-based inks is suggested for future work. The significance of this work in developing plant-based inks for inkjet printing of textiles lies in the convergence of sustainability and innovation. Plant-based inks can offer an eco-friendly alternative to traditional synthetic inks that are used currently, which provides a knowledge base for good practises meeting the environmentally conscious in the digital printing of the textile industry. These developed inks from this study can not only reduce the environmental impact but also promote a healthier ecosystem.

Supplementation of chestnut tannins in diets can improve meat quality and antioxidative capability in Hu lambs

Chestnut tannins (CNT), as a source of hydrolyzable tannins, positively affect the antioxidant status of livestock. In the current study, 90 male Hu lambs were used to investigate the effect of dietary CNT intake on growth performance, nutrient digestibility, meat quality and oxidative stability, rumen microbial, and the transcriptomes of muscle and liver. A completely randomized design with three CNT intake levels (0, 0.3%, and 0.6%) was used. Rumen microbial and nutrient digestibility were not significantly altered by CNT intake. Diets with 0.3% CNT intake significantly reduced the shear force, yellowness at 24 h, and C20:2 polyunsaturated fatty acids of lamb meat and malondialdehyde in serum and longissimus thoracis (LT) muscle. Meanwhile, the 0.3% CNT diet significantly increased average daily gain during the 1- 21 days and 64- 90 days, dry matter intake during the 1- 21 days, the slaughter weight, and liver index of lambs. The 0.3% CNT diet significantly increased C26:0 saturated fatty acids, total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase in LT muscle. The meat shelf life of 0.3% CNT and 0.6% CNT groups was prolonged by 8.7 h and 5.4 h, respectively. Transcriptomic analysis revealed that CNT supplementation can induce the expression of antioxidant enzyme gene (CAT, SOD1), and the differentially expressed genes were mainly involved in antioxidant activity, transferase activity, and adenosine triphosphate binding. These results suggest that 0.3% CNT intake can relieve the oxidative stress of lambs, and improve the stability of meat color and meat tenderness, due to the enhanced antioxidative capacity.

Recent Advances in Synthesis of Graphite from Agricultural Bio-Waste Material: A Review

Graphitic carbon is a valuable material that can be utilized in many fields, such as electronics, energy storage and wastewater filtration. Due to the high demand for commercial graphite, an alternative raw material with lower costs that is environmentally friendly has been explored. Amongst these, an agricultural bio-waste material has become an option due to its highly bioactive properties, such as bioavailability, antioxidant, antimicrobial, in vitro and anti-inflammatory properties. In addition, biomass wastes usually have high organic carbon content, which has been discovered by many researchers as an alternative carbon material to produce graphite. However, there are several challenges associated with the graphite production process from biomass waste materials, such as impurities, the processing conditions and production costs. Agricultural bio-waste materials typically contain many volatiles and impurities, which can interfere with the synthesis process and reduce the quality of the graphitic carbon produced. Moreover, the processing conditions required for the synthesis of graphitic carbon from agricultural biomass waste materials are quite challenging to optimize. The temperature, pressure, catalyst used and other parameters must be carefully controlled to ensure that the desired product is obtained. Nevertheless, the use of agricultural biomass waste materials as a raw material for graphitic carbon synthesis can reduce the production costs. Improving the overall cost-effectiveness of this approach depends on many factors, including the availability and cost of the feedstock, the processing costs and the market demand for the final product. Therefore, in this review, the importance of biomass waste utilization is discussed. Various methods of synthesizing graphitic carbon are also reviewed. The discussion ranges from the conversion of biomass waste into carbon-rich feedstocks with different recent advances to the method of synthesis of graphitic carbon. The importance of utilizing agricultural biomass waste and the types of potential biomass waste carbon precursors and their pre-treatment methods are also reviewed. Finally, the gaps found in the previous research are proposed as a future research suggestion. Overall, the synthesis of graphite from agricultural bio-waste materials is a promising area of research, but more work is needed to address the challenges associated with this process and to demonstrate its viability at scale.

Chestnut Wood Mud as a Source of Ellagic Acid for Dermo-Cosmetic Applications

Ellagic acid (EA) has long been recognized as a very active antioxidant, anti-inflammatory, and antimicrobial agent. However, its low bioavailability has often hampered its applications in health-related fields. Here, we report a phospholipid vesicle-based controlled release system for EA, involving the exploitation of chestnut wood mud (CWM), an industrial by-product from chestnut tannin production, as a largely available and low-cost source of this compound. Two kinds of CWM with different particle size distributions, indicated as CWM-A and CWM-B (<100 and 32 µm, respectively), containing 5 ± 1% w/w EA, were incorporated into transfersomes. The latter were small in size (~100 nm), homogeneously dispersed, and negatively charged. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated up to three-fold improvement in the antioxidant properties of CWM upon incorporation into transfersomes. The kinetics of EA released under simulated physiological conditions were evaluated by UV-Vis spectroscopy and HPLC analysis. The best results were obtained with CWM-B (100% of EA gradually released after 37 days at pH 7.4). A stepwise increase in the antioxidant properties of the released material was also observed. Cell-based experiments confirmed the efficacy of CWM-B transfersomes as antioxidant agents in contrasting photodamage.

Condensed Tannins, a Viable Solution To Meet the Need for Sustainable and Effective Multifunctionality in Food Packaging: Structure, Sources, and Properties

Condensed tannins (CT) have been the focus of increasing interest in the last years as a result of their potent biological properties, which have prompted their use in the food and feed sector as functional ingredients. The possible exploitation of these compounds as multifunctional additives for the implementation of active food packaging has also been recently appreciated. In this perspective, an overview of the structural features, accessible sources, methods of analysis, and functional properties of CT is provided, with the aim of critically emphasizing the opportunities offered by this widespread class of natural phenolic compounds for the rational design of multifunctional and sustainable food packaging materials.

Tuning of Proanthocyanidin Extract's Composition through Quaternary Eutectic Solvents Extraction

Currently available proanthocyanidins extraction methods rely on dedicated crops and have low specificity and yield which limits their industrial application. Consequently, the development of novel methodologies and the use of sustainable sources is of great importance. Eutectic solvents have been proposed has good alternatives for conventional solvents due to their low price, easiness of preparation, biocompatibility and ability of being custom made to a specific application. Herein the effective extraction of proanthocyanidins from grape pomace and the possibility of tuning the extract's characteristics such as mean degree of polymerization and galloylation percentage is explored by means of varying the composition of a quaternary eutectic solvent composed by choline chloride, glycerol, ethanol and water. It was found that mean degree of polymerization values can vary from 6.0 to 7.37 and galloylation percentage can vary from 32.5% to 47.1% while maintaining extraction yield above 72.2 mg of proanthocyanidins per g of biomass. Furthermore, the increase of temperature up to 100 °C has showed a significant effect on the extraction yield being possible to increase it by 238% when compared to the conventional extraction method.

Hydrolyzable vs. Condensed Wood Tannins for Bio-based Antioxidant Coatings: Superior Properties of Quebracho Tannins

Tannins have always been the subject of great interest for their countless properties, first of all their ability to produce functional coatings on a variety of materials. We report herein a comparative evaluation of the antioxidant properties of wood tannin-based coated substrates. In particular, nylon membrane filters were functionalized with chestnut (hydrolyzable) or quebracho (condensed) tannins by dip coating under different conditions. The efficiency of functionalization was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays, which invariably highlighted the superior ability of condensed tannins to induce the formation of a functional and robust coating. The results of the antioxidant assays revealed also the deleterious effects of aerial or enzymatic oxidation conditions on substrate functionalization, being more significant in the case of hydrolyzable tannins. On the other hand, the use of oxidizing conditions allowed to obtain more stable coatings, still exhibiting good antioxidant properties, in the case of condensed tannins. The presence of iron ions did not lead to a significant improvement of the coating efficiency for either tannins. The systematic approach used in this work provides novel and useful information for the optimal exploitation of tannins in antioxidant functional coatings.

Effects of the Incorporation of Tannin Extract from Quebracho Colorado Wood on Color Parameters, Lipid Oxidation, and Sensory Attributes of Beef Patties

The tannin extract of Quebracho Colorado wood (Schinopsis balansae and Schinopsis lorentzii) is rich in proanthocyanidins with demonstrated powerful scavenging activity against free radicals. Currently, this extract is used in the wine industry to improve sensory attributes, stabilize color, and act as a redox buffer. In this study, we hypothesized that condensed tannins from Quebracho Colorado wood could be incorporated into beef patties as a natural antioxidant source to improve shelf life. Patties formulated with tannin extract (0, 0.5%, 1%, and 1.5%) were evaluated for instrumental color, lipid oxidation, and sensory attributes. Patties were displayed under refrigerated aerobic conditions (PVC film) for 6 days for color and lipid oxidation analysis. For sensory analysis, patties were frozen immediately after formulation. Control (0%) samples were redder than samples formulated with 1.5% tannin during the first 4 days of display. For b*, samples formulated with 1.5% tannin were predominantly yellower during display. After day 4, chroma values were higher in samples formulated with 1.5% tannin. The inclusion of tannin extract improved lipid stability, however, levels above 0.5% decreased tenderness, softness, juiciness, and overall desirability of patties.

Antioxidant Properties of Agri-food Byproducts |and Specific Boosting Effects of Hydrolytic Treatments

Largely produced agri-food byproducts represent a sustainable and easily available source of phenolic compounds, such as lignins and tannins, endowed with potent antioxidant properties. We report herein the characterization of the antioxidant properties of nine plant-derived byproducts. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated the superior activity of pomegranate peels and seeds, grape pomace and pecan nut shell. An increase in the antioxidant potency was observed for most of the waste materials following a hydrolytic treatment, with the exception of the condensed tannin-rich pecan nut shell and grape pomace. UV-Vis and HPLC investigation of the soluble fractions coupled with the results from IR analysis and chemical degradation approaches on the whole materials allowed to conclude that the improvement of the antioxidant properties was due not only to removal of non-active components (mainly carbohydrates), but also to structural modifications of the phenolic compounds. Parallel experiments run on natural and bioinspired model phenolic polymers suggested that these structural modifications positively impacted on the antioxidant properties of lignins and hydrolyzable tannins, whereas significant degradation of condensed tannin moieties occurred, likely responsible for the lowering of the reducing power observed for grape pomace and pecan nut shell. These results open new perspectives toward the exploitation and manipulation of agri-food byproducts for application as antioxidant additives in functional materials.

Natural Phenolic Compounds for Health, Food and Cosmetic Applications

Based on their potent antioxidant properties, natural phenolic compounds have gained more and more attention for their possible exploitation as food supplements, as well as functional ingredients in food and in the cosmetic industry [...].

Bioactive Phenolic Compounds From Agri-Food Wastes: An Update on Green and Sustainable Extraction Methodologies

Phenolic compounds are broadly represented in plant kingdom, and their occurrence in easily accessible low-cost sources like wastes from agri-food processing have led in the last decade to an increase of interest in their recovery and further exploitation. Indeed, most of these compounds are endowed with beneficial properties to human health (e.g., in the prevention of cancer and cardiovascular diseases), that may be largely ascribed to their potent antioxidant and scavenging activity against reactive oxygen species generated in settings of oxidative stress and responsible for the onset of several inflammatory and degenerative diseases. Apart from their use as food supplements or as additives in functional foods, natural phenolic compounds have become increasingly attractive also from a technological point of view, due to their possible exploitation in materials science. Several extraction methodologies have been reported for the recovery of phenolic compounds from agri-food wastes mostly based on the use of organic solvents such as methanol, ethanol, or acetone. However, there is an increasing need for green and sustainable approaches leading to phenolic-rich extracts with low environmental impact. This review addresses the most promising and innovative methodologies for the recovery of functional phenolic compounds from waste materials that have appeared in the recent literature. In particular, extraction procedures based on the use of green technologies (supercritical fluid, microwaves, ultrasounds) as well as of green solvents such as deep eutectic solvents (DES) are surveyed.