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Microfluidic paper-based analytical devices (µPADs) represent one of the promising green analytical strategies for low-cost and simple determination of various analytes. The actual task is the development of such devices for quantitation of antioxidants, e.g., flavonoids. In this paper, possibilities of a novel three-reagent µPAD including silver nitrate, 4-nitrophenyldiazonium tetrafluoroborate, and iron(III) chloride as reagents are assessed with respect to the determination of dihydroquercetin. It is shown that all the three reagents produce different colorimetric responses that can be detected by a mini-spectrophotometer–monitor calibrator or by a smartphone. The method is applicable to direct measuring high contents of dihydroquercetin (the linearity range is 0.026–1 mg mL−1, and the limit of detection is 7.7 µg mL−1), which is favorable for many dietary supplements. The analysis of a food supplement was possible with the relative standard deviations of 9–26%, which is satisfactory for quantitative and semiquantitative determinations. It was found that plotting a calibration graph in 3D space of the three reagents’ responses allows us to distinguish dihydroquercetin from its close structural analogue, quercetin.

In protecting cultural heritage, deacidification is used to stabilize acidic papers, ensuring the neutralization of acids present in the paper. But in the process of aging, several mechanisms of degradation occur simultaneously. Therefore, substances used to stabilize the paper should contain an antioxidant component in addition to the deacidifying component. The effect of the antioxidant (hindered amine light stabilizers—HALS type) on the stabilization of lignin-containing acid papers during accelerated aging was studied in this work. The effective deacidification component was magnesium; the solvent was hexamethyldisiloxane (HMDSO). The 4-amino-2,2,6,6-tetramethylpiperidine series of hindered amine light stabilizers (HALS) was selected as appropriate for creating a modifying system based on HMDSO. The modification system was tested on samples of a model test acid lignin-containing paper (NOVO) and naturally aged acidic paper from the real book. The addition of substances to the proposed deacidification system has a favorable effect on stabilizing the pH during aging and provides the inhibition of the oxidative degradation products and stabilization of the cellulose degree of polymerization. It was confirmed that the application of the system containing deacidification and an antioxidant component may increase the effectiveness of the protection of acid groundwood paper heritage objects. Adding a tested antioxidant to the proposed deacidification system has a favorable effect on stabilizing the pH value for a long time in accelerated aging. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study on the physicochemical properties of rice oil, peanut oil, corn oil and Kraft paper immersed in these oils in the presence of antioxidants (butylated hydroxytoluene, tertiary butyl hydroquinone and Naugalube¯ 750). The experiments are performed on new and aged conditions. Ageing of oils is carried at 115 °C for 96 hours while Kraft paper is aged in oils at 130 °C for 164 hours. Both closed and open cup methods are used for ageing. The results show that ageing insignificantly affects the breakdown voltage, but markedly increases the acid number and the viscosity of the vegetable oils. The combination of tertiary butyl hydroquinone and either butylated hydroxytoluene or Naugalube¯ 750 slightly increases the breakdown voltage, but significantly raises the oxidation stability of the vegetable oils. This results in a reduction in the viscosity and the acid number of the vegetable oils. Moisture significantly affects the breakdown voltage of both vegetable and mineral oil. High moisture content results in low breakdown voltage. The results also show that ageing insignificantly affects the breakdown voltage, but markedly decreases the tensile strength of oil-impregnated paper. Although the presence of antioxidants does not increase the breakdown voltage of aged paper, these additives slow down the ageing process. This results in an increase in tensile strength of the paper. [ABSTRACT FROM AUTHOR]

This work reports the development of low-cost and rapid multiplexed colorimetric assay of antioxidants (total phenolics, antioxidant capacity, flavonoids and anthocyanins) in wines at daisy-shaped fluidic paper-based analytical devices (PADs). The desired fluidic patterns were formed on paper by pen drawing and colorimetric reagents were immobilized at the 6 peripheral test zones. The sample was added at the central sample zone, migrated to the test zones and reacted with the immobilized reagents producing characteristic colors that were captured and analyzed. The paper-based approach was applied to the analysis of several wine samples and the results were statistically correlated to standard solution-based colorimetric assays, indicating that it could be reliably used for ranking wines according to their antioxidants content. In addition, the paper-based analytical methodology is simple, instrument-free, portable, cost-effective, rapid and environment friendly. [Display omitted] • Daisy-shaped paper-based analytical devices (PADs) were fabricated by pen drawing. • The PADs were used for a sextuple antioxidant/phenolics/anthocyanins/flavonoids assay. • Reagents were added to the 6 peripheral test zones and sample was added to the central sample zone. • The results of the assay for 18 wines correlated well with those of solution-based assays (R2 > 0.97). • The paper-based analytical methodology is simple, instrument-free, portable, cost-effective, rapid and environment friendly. [ABSTRACT FROM AUTHOR]

Microfluidic paper-based analytical devices (µPADs) represent one of the promising green analytical strategies for low-cost and simple determination of various analytes. The actual task is the development of such devices for quantitation of antioxidants, e.g., flavonoids. In this paper, possibilities of a novel three-reagent µPAD including silver nitrate, 4-nitrophenyldiazonium tetrafluoroborate, and iron(III) chloride as reagents are assessed with respect to the determination of dihydroquercetin. It is shown that all the three reagents produce different colorimetric responses that can be detected by a mini-spectrophotometer–monitor calibrator or by a smartphone. The method is applicable to direct measuring high contents of dihydroquercetin (the linearity range is 0.026–1 mg mL−1, and the limit of detection is 7.7 µg mL−1), which is favorable for many dietary supplements. The analysis of a food supplement was possible with the relative standard deviations of 9–26%, which is satisfactory for quantitative and semiquantitative determinations. It was found that plotting a calibration graph in 3D space of the three reagents' responses allows us to distinguish dihydroquercetin from its close structural analogue, quercetin. [ABSTRACT FROM AUTHOR]

Copyright of Restaurator is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a study conducted to examine whether interleaving paper impregnated with a combination of the antioxidant sodium bromide and calcium carbonate would be able to reduce the degradation of iron-gall ink containing papers. Four types of interleaving papers were studied, pure paper, paper with calcium carbonate and paper with calcium carbonate and sodium bromide. Interleaving papers were prepared by immersing Whatman filter paper No. 1 once, for 5 minutes in a saturated aqueous solution of calcium hydroxide or twice with intermediate drying. A third set was left untreated.

The focus of this research is the stabilisation of paper with Verdigris, a green copper pigment. Due to its corrosive effects on paper, many important documents, paintings and maps are in danger. The efficiency of several commercially available deacidification agents on paper samples with Verdigris was tested, including magnesium-based Bookkeeper® dispersion, nano calcium hydroxide containing Nanorestore® and CaLoSiL® dispersions as well as a recently developed dispersion of nano calcium carbonate. The antioxidant tetrabutylammonium bromide was tested either alone or in combination with nano calcium based deacidification agents. The effect of the treatments was evaluated using colour, tensile strength, degree of polymerization and pH measurements. The results indicate that acidic degradation does not play a major role during accelerated degradation of paper containing Verdigris with moderately acidic pH value and that oxidative decay could be the main culprit of the decay. The method described, which involves the use of antioxidant tetrabutylammonium bromide in combination with calcium carbonate based deacidification dispersion, was proved to have a superior effect against degradation of paper with Verdigris in comparison to the treatments which involve deacidification agents only. Nano calcium hydroxide based deacidification agents result in high pH values of the paper samples and therefore cannot be advised for use on paper documents. [ABSTRACT FROM AUTHOR]

A cost-effective assay for antioxidant using simple cotton thread combining paper based device with mobile phone detection has been investigated. Standard and sample solutions flow along a bunch of cotton thread treated with sodium hydroxide via microfluidic behaviors without external pumping. The analyte solution reacts with the reagents that have been immobilized on the paper strip fixed at the end of the cotton bunch. The developed platforms were used for the assays of total phenolic content and antioxidant capacity by employing Folin-Ciocalteu and 2, 2-diphenyl-1-picryhydrazyl (DPPH) respectively. Simple detection can be made by employing a mobile phone camera (iPhone 4S) with Image J or Photoshop for image processing and evaluation. Gallic acid was used as a reference standard in this work, as its polyphenol structures can be found in many plants. The total phenolic content is expressed as gallic acid equivalents (GAE) (mg/g material). Inhibition capacity is calculated by the equation: % I = [(I o – I s )/ I o ] × 100, where I s is the relative magenta intensity (CMYK mode) of sample, and I o the relative magenta intensity of DPPH•. IC 50 inhibition can be estimated from the graph and can be used for the antioxidant capacity consideration. Applications to the assay green tea samples were demonstrated. The total phenolic contents in the green tea samples were found to be 48–105 mg/g, with %RSD of less than 10 for that of higher 50 GAE mg/g and IC 50 values of the samples studied were 25–50 mg/L. The results obtained by the developed methods agree with that of the standard methods. [ABSTRACT FROM AUTHOR]

Copyright of Chemija is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work aimed to explore the use of native herbs for the removal of heavy metals from pulp and paper industry wastewater, with the view of applying them as part of a multidisciplinary approach for detoxification. Results showed that after in-situ phytoremediation by the native herbs, the heavy metal, and metalloid contents in the wastewater were reduced by almost 60%. Heavy metal analysis of the plant tissues revealed that Fe accumulation was highest in all the tested plants. In general, the bioconcentration factor (BCF) was higher than one (>1) for all the metals except for Cd, suggesting most of the metals were concentrated in the plant tissues. In particular, As was concentrated significantly in Momordica doica and Cannabis sativa with elevated BCF of 269.46 and 131.20, respectively. High translocation factor (>1) was observed in P. hysterophorus and Tribulus terrestris for Cr (5.63) and Cd (7.53), respectively. Results showed most of the native plants examined in this study had hyperaccumulating tendency. Transmission electron microscope analysis of plant root tissues showed abundant metal depositions in the root cell wall, cytoplasm, and vacuole as strong evidence of the in-situ phytoremediation capability of these plants. Antioxidants activities of the plants such as superoxide dismutase, catalase, hydrogen peroxidase, peroxidase, and ascorbate peroxidase production were also noted to be higher than the control. These results support the use of native plants as a novel green process that can be integrated into the multidisciplinary treatment of hazardous industrial wastewater in the polluted sites. [Display omitted] • Disposed wastewater contains mixture of metals and recalcitrant organic pollutants. • BCF and TF values have propensity of hyperaccumulators plants. • Findings of results can be useful for eco-restoration process at polluted site. [ABSTRACT FROM AUTHOR]

Abstract We report the first use of a paper-based device as a simple, low-cost and rapid detection platform for simultaneous determination of antioxidant activity and total phenolic content in food samples. Two antioxidant activity assays including 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonate) radical cation (ABTS) assay and cupric reducing antioxidant capacity (CUPRAC) assay and one total phenolic content assay, Folin Ciocaltue reagent (FC) assay were simultaneously employed as a proof-of-concept. The device composed of a central sample zone connected to four pretreatment zones and consecutive detection zones to accommodate all three assays and a sample blank measurement. The analysis was achieved by dropping the samples onto the sample zone to flow to the pretreatment and detection zones containing the stored reagents for each antioxidant assay making the color change that was measured using imageJ software. Assay optimization including key reagent concentrations, reaction time, and surface modification were carried out to obtain sensitive and wide linear rage analyses. Various antioxidant standards were then evaluated to determine the analytical features of the method. The paper-based assays were successfully applied to detect antioxidant activity and total phenolic content in 10 beverage samples with similar gallic acid equivalent (GAE) values to those obtained from traditional assays at a 95% confidence interval. Moreover, the GAE values of the samples obtained from three assay analyses were well correlated to each other with relatively high Pearson's correlation coefficients. These results indicated that the assays gave accurate results and are suitable for simultaneous analysis of antioxidant activity and total phenolic content in real samples. Graphical abstract fx1 Highlights • Multiple antioxidant and total phenolic content assays can be performed simultaneously on a single PAD. • Various information on antioxidant mechanisms can be obtained in one analysis. • Rapid analysis with low reagent and sample consumption for multiple antioxidant analysis. [ABSTRACT FROM AUTHOR]

MXene‐based thermal camouflage materials have gained increasing attention due to their low emissivity, however, the poor anti‐oxidation restricts their potential applications under complex environments. Various modification methods and strategies, e.g., the addition of antioxidant molecules and fillers have been developed to overcome this, but the realization of long‐term, reliable thermal camouflage using MXene network (coating) with excellent comprehensive performance remains a great challenge. Here, a MXene‐based hybrid network comodified with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi) molecules is designed and fabricated. Notably, the presence of appreciated HA molecules restricts the oxidation of MXene sheets without altering infrared stealth performance, superior to other water‐soluble polymers; while the HSi molecules can act as efficient cross‐linking agents to generate strong interactions between MXene sheets and HA molecules. The optimized MXene/HA/HSi composites exhibit excellent mechanical flexibility (folded into crane structure), good water/solvent resistance, and long‐term stable thermal camouflage capability (with low infrared emissivity of ≈0.29). The long‐term thermal camouflage reliability (≈8 months) under various outdoor weathers and the scalable coating capability of the MXene‐coated textile enable them to disguise the IR signal of various targets in complex environments, indicating the great promise of achieved material for thermal camouflage, IR stealth, and counter surveillance. [ABSTRACT FROM AUTHOR]

Rice paper prepared from non-glutinous rice commonly found in Southeast Asia is used very often in the making spring rolls. Moringa oleifera is one of the most important herbs having high antioxidant and pharmacological properties. In order to improve the functional properties of rice paper, it’s necessary to enrich rice paper with moringa. This research was conducted during 2020 at Soc Trang Nanotech laboratory, Soc Trang province, Vietnam to examine the feasibility of Moringa oleifera extract in different enrichments (2.5, 4.0, 5.5, 7.0, 8.5%) to the rice paper quality in respect of firmness (N), total phenolic content (TPC, µg/mL), total flavonoid content (TFC, µg/mL), free radical scavenging activity (% DPPH), ferric reducing antioxidant power (FRAP, µg/mL) and sensory characteristic (score). Results revealed that there was a reduction of firmness (from 27.23±0.02 N to 11.75±0.00 N) but increment of antioxidant activities such as TPC (from 64.75±0.00 µg/ mL to 79.54±0.01 µg/mL), TFC (from 11.63±0.01 µg/mL to 18.66±0.03 µg/mL), % DPPH (from 26.11±0.02 % to 32.45±0.01 %), FRAP (68.47±0.00 µg/mL 76.14±0.02 µg/mL) and enrichment of organoleptic property (from 6.85±0.03 to 8.29±0.00) by adding Moringa oleifera extract. Firmness, TPC, TFC, % DPPH, FRAP and sensory score were shown the acceptable values at 7.0% Moringa oleifera extract supplementation. Rice paper enriched with Moringa oleifera extract showed promising antioxidant potential. Moringa oleifera extract could be applied as a phytochemical source suitable in rice paper preparation. [ABSTRACT FROM AUTHOR]

Natural oils derived from linseed, rapeseed, soybean, and a special breed of sunflower were tested for the production of maleated fatty oils for paper sizing in the ene-reaction with maleic anhydride. All these maleated oils were subjected to a conventional sizing test proving their ability to hydrophobize handsheets. Natural oils having only monounsaturated fatty acid residues (oleic acid) in the triglycerides worked best by having lower product viscosity and higher yields. The optimized production procedure employs antioxidant addition, an increased maleic anhydride:triglyceride ratio of 4:1, as well as increased pressure to reduce undesired polymeric byproducts and to increase yield. [ABSTRACT FROM AUTHOR]

Pinus radiata barks obtained from tress of different ages, as subproduct of pulp and paper (trees less than 10 years) and sawmill (trees between 20 to 25 years) industries, were used to produce extracts containing phenolic compounds. A factorial design 2³ was used to evaluate the influence of the variables temperature (25 - 35 ºC), solvent type (acetone - ethanol) and extraction time (1-12 h). The extracts were compared in their extraction yield (%), total phenols (by FolinCiocalteau), and radical scavenging activity (by DPPH). The extract obtained from old trunks presented a higher extraction yield than from young trees. The highest yield value was 2.56%, which was obtained using acetone as solvent for 12 h and 35°C. The highest concentration of phenol (5.84± 0.18 g CE g extract-1), and scavenging activity (IP=86.1± 4.4%) were also obtained for this type of extract. The extraction duration was the variable that most influenced the parameters studied. The bark’s radical scavenging power was greater than BHT (40%) and slightly lower than ascorbic acid (92%), common commercial antioxidants.

The paper mulberry (Broussonetia papyrifera) leaf is rich in alkaloids and flavonoids, which has high medicinal and feeding value. We aimed to analyze the effects of B. papyrifera leaf extract on growth performance, antioxidant capacity, immune functions, and fecal microflora of weaned piglets. Thirty healthy, 28-day-old piglets were randomly assigned to three groups and fed with a basal diet supplemented with 0, 150, and 300 g/t B. papyrifera leaf extract for 42 days (control group, group I, and group II) separately. The result revealed that the final weight of piglets in group II was higher than the other groups, and the diarrhea rate in this group was 62.9% lower than in the control group. The feed conversion ratio in group I was significantly lower than the other two groups. Higher blood urine nitrogen concentration was noted in group II, higher glutathione peroxidase and catalase in group II, higher superoxide dismutase in the control group, and higher immune globulins (Ig) IgG, IgA, and IgM in group II. There was no significant difference in community richness and community diversity among the three groups of fecal samples. The relative level of Roseburia was higher in groups I and II, while Lactobacillus was higher in the control group. In conclusion, supplementation with B. papyrifera leaf extract at a certain dosage can increase growth performance and antioxidant capacity of weaned piglets, reduce the occurrence of diarrhea, enhance immune functions and disease resistance, and affect the composition of fecal microflora. [ABSTRACT FROM AUTHOR]

Pinus radiata barks obtained from tress of different ages, as subproduct of pulp and paper (trees less than 10 years) and sawmill (trees between 20 to 25 years) industries, were used to produce extracts containing phenolic compounds. A factorial design 23 was used to evaluate the influence of the variables temperature (25 – 35 ºC), solvent type (acetone - ethanol) and extraction time (1-12 h). The extracts were compared in their extraction yield (%), total phenols (by FolinCiocalteau), and radical scavenging activity (by DPPH). The extract obtained from old trunks presented a higher extraction yield than from young trees. The highest yield value was 2.56%, which was obtained using acetone as solvent for 12 h and 35°C. The highest concentration of phenol (5.84±0.18 g CE g extract-1), and scavenging activity (IP=86.1±4.4%) were also obtained for this type of extract. The extraction duration was the variable that most influenced the parameters studied. The bark’s radical scavenging power was greater than BHT (40%) and slightly lower than ascorbic acid (92%), common commercial antioxidants.

Copyright of Nigde Omer Halisdemir University Journal of Engineering Sciences / Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi is the property of Nigde Omer Halisdemir Universitesi (NOHU), Muhendislik Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract A simple and sensitive device is presented based on the use of pencil-drawn paper based electrochemical detector placed at the end of a cotton thread fluidic channel in wall-jet configuration. This innovative and fast responding electroanalytical system can be adopted for both single and dual electrode electrochemical detection, this last achieved by applying two different potentials at two independent working electrodes drawn on the opposite faces of the paper based detector. Its performance was preliminarily optimized by adopting hexacyanoferrate(II) as probe species undergoing reversible electrochemical processes. These devices were then used for the single electrode detection of ascorbic acid in aqueous samples and the dual electrode detection of orthodiphenols in extra virgin olive oils (EVOOs). In fact, these devices enable hydrophilic orthodiphenols, typically present in EVOOs (extracted by a 80:20% v/v acetonitrile/water mixture), to be discriminated from hydrophilic monophenols instead present in almost all vegetable oils. Flow-injections runs were conducted by using a 0.01 M H 2 SO 4 + 0.5 KCl running electrolyte allowing the rapid and selective detection of hydrophilic orthodiphenols with satisfactory sensitivity and a low enough detection limit (2 μM). Different real samples of EVOOs and sunflower oils were analyzed. Abundant enough contents of orthidiphenols were found in EVOO samples, while no trace of these antioxidants was found in sunflower oils. Graphical abstract Image 1 Highlights • Paper based wall-jet electrochemical detectors coupled with cotton-thread fluidic systems are proposed. • A pencil drawing approach was used to construct electrochemical detectors. • Dual electrode configuration of electrochemical detectors enables detection of analytes with reversible behavior. • Simple and inexpensive methods for the detection of ascorbic acid and orthodiphenols are proposed. [ABSTRACT FROM AUTHOR]

The current study aimed to identify and analyze the 100 most cited papers on the topic of nutraceuticals and functional foods. Scopus database was searched to extract bibliometric data. Two-thirds of the 100 most cited papers were reviews. Papers were mostly published in food science and nutrition journals, and one-third were published in seven journals, namely: British Journal of Nutrition (6), Critical Reviews in Food Science and Nutrition (6), Journal of Food Science (5), Trends in Food Science and Technology (5) , American Journal of Clinical Nutrition (4) , Food Chemistry (4) and Journal of Nutrition (4). Topics with high citation counts dealt with prebiotics, probiotics, antioxidants and phenolic content. Hot topics with over 1000 citations per paper include bifidobacterium (1147), colon (1032) and lipid metabolism (1013). The United States and Europe were major places of origin. These results can serve as a quick benchmarking reference for researchers or general public members. [ABSTRACT FROM AUTHOR]

Iron gall ink was the most widely used writing ink for paper from the Middle Ages to the twentieth century. Unfortunately, the ink ingredients contain corrosive transition metal ions and acids that cause severe damage to the paper carrier. New or improved paper conservation methods for iron gall ink stabilization are constantly sought. The aim of the study was evaluation of a recently proposed stabilization treatment, adapted to lower relative humidity, applied to various model and historical paper samples containing iron gall ink. The effect of stabilization treatment on paper samples during artificial thermal aging was followed by the determination of the molecular weight distribution by size exclusion chromatography and colorimetry. Migration of iron and copper compounds from the ink lines was monitored by laser ablation inductively coupled plasma mass spectrometry. The results demonstrate that effective stabilization of iron gall ink-containing paper can be successfully achieved by interleaving with papers impregnated with the antioxidant tetrabutylammonium bromide and alkaline buffer under experimental conditions. Negative side effects of the stabilization treatment, such as migration of iron or copper ions from the ink lines and changes of color after the treatment and after accelerated thermal degradation, were limited, proving that the proposed stabilization treatment can be considered for future use by conservators. [ABSTRACT FROM AUTHOR]

The present study investigates the influence of on-tree fruit bagging on the quality and shelf life of mango (Mangifera indica L. cv. 'Samar Bahisht Chaunsa') during cold storage (12 °C ± 1; 85–90% RH) for 0, 10 and 20 days (d) and subsequent shelf storage under ambient conditions (25 °C ± 1; 60–65% RH). Fruits were covered with brown paper bags at the marble stage and then harvested at commercial maturity. Results showed that 0 d and 10 d cold-stored fruits, irrespective of bagging treatments, retained eatable quality and shelf-life up to 7 d and 5 d during ambient storage, respectively. However, bagged fruits had better postharvest performance compared with non-bagged fruits by exhibiting slower weight loss, higher fruit firmness, more total soluble solids, vitamin C and total phenolic content and higher activities of catalase and superoxide dismutase during cold storage and ambient shelf storage. On the other hand, 20 d cold-stored fruits, both bagged and non-bagged, were decayed when kept under ambient conditions. It is proposed that mango fruit bagging could be a potential cultural practice to preserve postharvest quality up to 10 d of cold storage, followed by 5 d under ambient conditions. [ABSTRACT FROM AUTHOR]

Paper-based analytical devices are an emerging class of lightweight and simple-to-use analytical platform. However, challenges such as instrumental requirements and chemical reagents durability, represent a barrier for less-developed countries andmarkets. Herein, we report an advanced laminated device using red emitting copper nanocluster and RGB digital analysis for signal improvement. Upon RGB system assistance, the device signal-to-background ratio and the calibration sensitivity are highly enhanced under a filter-free setup. In addition, the calibration sensitivity, limit of detection, and coefficient of determination are on par with those determined by instrumental fluorescence analysis. Moreover, the limitation of using oxidation-susceptible fluorescent nanomaterials is overcome by the introduction of protecting tape barriers, antioxidative sheets, and lamination enclosing. The robustness of device is highly advanced, and the durability is prolonged to more than tenfold. [ABSTRACT FROM AUTHOR]

Nowadays, climate change is not the only threat facing our planet. There are also other types of pollution such as waste that poisons soils and water and kills plants, harming humans and animals. Sustainability represents a key issue for the actual Global Citizen. For this reason, our article is dedicated to offering biofriendly solutions to decrease wastes, give them a positive meaning, such as a substrate for an edible oyster fungus with nutritive and biological properties usefully for humans. Three types of wastes such as coconut coir, pine sawdust, and paper waste—representative symbols of pollution in Ecuador—have been tested as suitable growing substrate for the edible fungi Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm by analyzing parameters such as Biological Efficiency, Mushroom Yield, and Productive Rate. The influence of these "waste" substrates on the nutritive (protein content), biological characteristic (antioxidant activity), and the content of human-health-sustaining compounds (phenols, flavonoids) were also evaluated using the Kjeldahal, DPPH, ABTS, FRAP, and Folin–Ciocalteu methods. The results indicate that all the waste products represent desirable substrates for growing the edible fungi, with more focus on coconut coir waste (one of the principal pollution problems in Ecuador), but that also achieved the increase in the fungi's desirable characteristics. Coconut coir waste could be an environmentally friendly solution that also offers for humans additional nutritive and healthy benefits. [ABSTRACT FROM AUTHOR]

Electrochemical behavior of three synthetic antioxidants, Butylated hydroxyltoluene (BHT), Butylated hydroxylanisole (BHA), and tert-Butyl hydroquinone (TBHQ) was researched by differential pulse voltammetry (DPV) technique on carbon paste electrode (CPE). According to this, a new method for the simultaneous determination of BHA, BHT, and TBHQ alone or in their mixtures was developed in order to obtain optimum concentration antioxidants against “ink corrosion” phenomenon in the iron gall inked papers. DPV can be used for quantitative data determination and also analysis studies on the kinetics, thermodynamics and mechanism of electrochemical reaction parameters. The voltammetric peaks of these antioxidants show well-defined and separated oxidation peaks based on their oxidation of BHA, BHT, and TBHQ. The proposed procedure is to provide a relationship between the peak current and analyte concentration. In addition, we found that during the redox reactions of TBHQ, BHA, and BHT, the redox peak currents increased and peak potentials highly shifted that these conditions can be attributed to the advantages of their strongly electro-active electrode. More results suggest that they have the same oxidation products. The obtained results indicate the sensitive, precise, and accurate method that can be an analytical alternative for existing methods. [ABSTRACT FROM AUTHOR]

Abstract: Current study presents the effect of irrigation with different compositions (0%, 20%, 40%, 60%, 80% and 100%) of PBM effluent on growth and antioxidant potential of Brassica rapa var. rapa L. plants. Seeds were exposed to different PBM effluent compositions, which resulted in significant decrease in their germination potential with elevated delay index. Significant changes in growth parameters (plant height, number of leaves and leaf area) were recorded for turnip plants at regular intervals (25, 50 and 75d) as function of PBM effluent proportion. Response of biochemical and antioxidant constituents in different parts of turnip, against stress induced by PBM effluent, was assessed by estimating the contents of chlorophyll (a+b), carotenoids, protein, phenolics, flavonoids, ascorbic acid and malondialdehyde. Antioxidant activity was evaluated by measuring DPPH radical scavenging potential. The results of this study suggest that the impact of PBM effluent irrigation is dependent on concentration of effluent in irrigation mixture and is very clear on plant growth and antioxidant attributes. Maximum benefits were secured at 40% PBM effluent to irrigate turnip plants till maturity while higher concentrations were found useful for shorter period (25–50d). [Copyright &y& Elsevier]

Effects of different concentrations of wastewater (chemical oxygen demands of 300, 175 and 50 mg•L-1) from a paper mill on seedling growth and antioxidant system in reeds were tested in experimental pools that simulated the wetland ecosystem. Root length, biomass and moisture content, but not shoot moisture content and plant height, significantly increased with increases in wastewater concentration. At 300 mg•L-1, shoot biomass increased by 52.5% and root biomass increased by 73.05% over the control. Malondialdehyde content, production rate of superoxide anions and hydrogen peroxide content all decreased with increasing concentration. At 300 mg•L-1, malondialdehyde content, production rate of superoxide anions and hydrogen peroxide content were 0.34, 0.24 and 0.16 times, respectively, those of the control in leaves and were 0.25, 0.19 and 0.17 times, respectively, those of the control in roots. Superoxide dismutase, peroxidase and catalase activities and ascorbic acid and glutathione contents in reeds significantly increased with increasing concentrations of wastewater. These results suggest that a concentration of 300 mg•L-1 could improve the activities of antioxidant enzymes, inhibit the generation of reactive oxygen species and reduce the generation of malondialdehyde, thus effectively alleviating the damage caused by salinity in wetland soil. [ABSTRACT FROM AUTHOR]

We report a simple, low-cost, one-step fabrication method for microfluidic paper-based analytical devices (μPAD) using only polystyrene and a patterned screen. The polystyrene solution applied through the screen penetrates through the paper, forming a three-dimensional hydrophobic barrier, defining a hydrophilic analysis zone. The optimal polystyrene concentration and paper types were first investigated. Adjusting polystyrene concentration allows for various types of paper to be used for successful device fabrication. Using an optimized polystyrene concentration with Whatman#4 filter paper, a linear relationship was found to exist between the design width and the printed width. The smallest hydrophilic channel and hydrophobic barrier that can be obtained are 670 ± 50 μm and 380 ± 40 μm, respectively. High device-to-device fabrication reproducibility was achieved yielding a relative standard deviation (%RSD) in the range of 1.12–2.54% (n = 64) of the measured diameter of the well-shaped fabricated test zones with a designed diameter of 5 and 7 mm. To demonstrate the significance of the fabricated μPAD, distance-based and well-based paper devices were constructed for the analysis of H2O2 and antioxidant activity, respectively. The analysis of H2O2 in real samples using distance-based measurement with CeO2 nanoparticles as the colorimetric agent produced the same results at 95% confidence level, as those obtained using KMnO4 titration. A proof-of-concept antioxidant activity determination based on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was also demonstrated. The results verify that the polymer screen-printing method can be used as an alternative method for μPAD fabrication. [ABSTRACT FROM AUTHOR]

A simple, sensitive and fast responding device is described for the discrimination of hydrophilic ortho-diphenols, whose presence in abundant enough amounts is typical for extra virgin olive oils (EVOOs), from hydrophilic mono-phenols instead present in almost all vegetable oils. It consists of a dual electrode detector pencil-drawn at the end of a paper microfluidic channel, defined by hydrophobic barriers, where samples of these antioxidants, extracted from vegetable oils by a 80:20% v/v acetonitrile/water mixture, were applied. Thin-layer chromatographic runs conducted by using a 0.01 M H 2 SO 4 + 1 M KCl running buffer allowed the selective detection of hydrophilic ortho-diphenols by profiting from the fact that they undergo reversible oxidation at less positive potentials than those required by monophenols for displaying their irreversible anodic process. On this basis, a potential for the oxidation of hydrophilic ortho-diphenols was applied to the upstream pencil-drawn electrode (W 1 ) (at which a minor fraction of mono-phenols was also oxidized), while a potential for the reverse process involving the sole product (ortho-quinones) of the reversible oxidation of ortho-diphenols was imposed at the downstream pencil-drawn working electrode (W 2 ). Thus, cathodic peak currents linearly dependent on analyte concentrations could be recorded at W 2 which led to a satisfactory detection limit (8 μM, equivalent to 1.23 mg/L) even when working electrodes W 1 and W 2 with same dimensions were employed. Improved sensitivities and lower detection limits were achieved by increasing the dimensions of W 2 with respect to W 1 , thanks to the improvement of the collection efficiency. Throughout this investigation, hydroxytyrosol (HTy) and tyrosol (Ty) were adopted as models of ortho-diphenols and mono-phenols, respectively, in view of their abundant presence in EVOOs. Real samples of EVOO from different production companies, of a simple olive oil and of a sunflower oil were analyzed. Different hydrophilic ortho-diphenol contents were found in EVOO samples (up to 40.8 mg/kg), while only a negligible amount turned out to be present in simple olive oil. No trace of these antioxidants were instead found in sunflower oil, as expected. All concentrations found were in good agreement with those detected by a more frequently employed spectrophotometric method used for the sake of comparison. [ABSTRACT FROM AUTHOR]

With the increasing interest in the health benefits arising from the consumption of dietary products rich in antioxidants, there exists a clear demand for easy-to-use and cost-effective tests that can be used for the identification of the antioxidant power of food products. Paper-based analytical devices constitute a remarkable platform for such expedient and low-cost assays with minimal external resources but efforts in this direction are still scarce. In this work we introduce a new paper-based device in the form of a sensor patch that enables the determination of antioxidant activity through analyte-driven on-paper formation of gold nanoparticles. The principle of detection capitalizes, for the first time, on the on-paper nucleation of gold ions to its respective nanoparticles, upon reduction by antioxidant compounds present in an aqueous sample. The ensuing chromatic transitions, induced on the paper surface, are used as an optical “signature” of the antioxidant strength of the solution. The response of the paper-based sensor was evaluated against a large variety of antioxidant species and the respective dose response curves were constructed. On the basis of these data, the contribution of each species according to its chemical structure was elucidated. For the analysis of real samples, a concentration-dependent colorimetric response was established against Gallic acid equivalents over a linear range of 10 μM–1.0 mM, with detection limits at the low and ultra-low μM levels (i.e. <1.0 μM) and satisfactory precision (RSD = 3.6–12.6%). The sensor has been tested for the assessment of antioxidant activity in real samples (teas and wines) and the results correlated well with commonly used antioxidant detection methods. Importantly, the sensor performed favorably for long periods of time when stored at moisture-free and low temperature conditions without losing its activity thus posing as an attractive alternative to the assessment of antioxidant activity without specialized equipment. The use of the sensor by non-experts for a rapid assessment of natural products in field testing is envisioned. Importantly, we demonstrate for the first time that analyte-mediated growth of nanomaterials directly on the paper surface could open new opportunities in paper-based analytical devices. [ABSTRACT FROM AUTHOR]

The bioactive constituents derived from plants attract the attention of researchers due to their potential applications in the medicinal field. In this regard, the proximate analysis and the cytotoxicity study of the plant materials play an important role in the phytochemical research. In the present work, estimation of total ash, moisture content, fiber content, crude protein, and carbohydrate were carried out under proximate analysis and the antioxidant activity of the anthocyanin present in the plant material was evaluated by DPPH(2,2-diphenyl-1-picrylhydrazyl) method. The separation of anthocyanin pigment from the plant material was done by paper chromatography (PC) technique and they are characterized by UV-spectrum, chemical test and the Rf values obtained from paper chromatography. This study also investigated the in vitro cytotoxicity of Pseuderanthemum reticulatum leaves by means of MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide)) assay using PBMC (Peripheral Blood Mononuclear Cell). The results of the proximate analysis showed that the plant material contains 7.6% of moisture content, 16.6% of total ash, 5.6% of crude protein, 23.0% of crude fiber, 3.82% of crude fat and 23.64% of carbohydrate. The free radical scavenging ability of the separated anthocyanin was found to be 72.58% at 10 µg/mL. The cytotoxicity investigation showed that the aqueous extract possess the IC50 value of 161.5 µg/mL. The high percentage of radical scavenging activity and low toxicity of the plant suggest that it can be extensively used for the investigation of the bioactive constituents and its applications. [ABSTRACT FROM AUTHOR]

The study examines India's performance on antioxidants using several quantitative measures such as India's global publication share, rank, growth rate and citation quality, its publication share in various sub-fields in terms of national share utilising last 10 year's (2001-10) publications data obtained from the Scopus database. We have also determined Indian share with international collaborative papers at the national level as well as is major international collaborative partners, besides analysing the characteristics of its high productivity institutions, authors and high-cited papers, etc. [ABSTRACT FROM AUTHOR]

The article examines the effect of antioxidants on the conservation process of archival materials containing iron gall ink. It provides a review of literature about the nature of iron gall inks and the essential qualities of industrial antioxidants. Furthermore, the authors present the experimental design of the study including the materials and equipment used, the preparation of samples, and the methodology. Based on the results, the authors concluded that the antioxidants had a positive effect in which they were able to reduce the deterioration of paper carrying iron gall ink.

Ferulic acid is an important phenolic antioxidant found in or added to diet supplements, beverages, and cosmetic creams. Two designs of paper-based platforms for the fast, simple and inexpensive evaluation of ferulic acid contents in food and pharmaceutical cosmetics were evaluated. The first, a paper-based electrochemical device, was developed for ferulic acid detection in uncomplicated matrix samples and was created by the photolithographic method. The second, a paper-based colorimetric device was preceded by thin layer chromatography (TLC) for the separation and detection of ferulic acid in complex samples using a silica plate stationary phase and an 85:15:1 (v/v/v) chloroform: methanol: formic acid mobile phase. After separation, ferulic acid containing section of the TLC plate was attached onto the patterned paper containing the colorimetric reagent and eluted with ethanol. The resulting color change was photographed and quantitatively converted to intensity. Under the optimal conditions, the limit of detection of ferulic acid was found to be 1 ppm and 7 ppm (S/N = 3) for first and second designs, respectively, with good agreement with the standard HPLC-UV detection method. Therefore, these methods can be used for the simple, rapid, inexpensive and sensitive quantification of ferulic acid in a variety of samples. [ABSTRACT FROM AUTHOR]