Influence of Neem oil pretreatment on the dyeing and antimicrobial properties of wool and silk fibers with some natural dyes

Wool and silk fibers pretreated with neem oil and dyed with chlorophyll, saffron red and yellow natural dyes using economic methods such as microwave heating and ultrasonic energy. The effect of neem oil concentrations on color strength (K/S) was measured. The results indicated that, wool and silk fibers pretreated with neem oil recorded higher color strength values than the untreated fibers. Fastness properties and the color yield of the dyes under investigation on wool and silk fibers were evaluated. The results indicated that, color fastness to rubbing, washing and perspiration of all dyes are excellent to good and are approximately the same in microwave and ultrasonic method. The antimicrobial activity against bacteria and fungi were tested, and the results indicated that the samples pretreated exhibited higher inhibition percent than the untreated fibers. The morphologies structure of the untreated and treated wool fibers were examined by scanning electron microscopy (SEM). The untreated samples have a rough surface. The pretreated samples of wool fibers were swelling compared to the untreated fibers .The diameter of the fibers increased and have smooth and even surfaces. The changes in the surface morphology due to the effect of active ingredients of treatment with neem oil. This behavior as swelling and increase in diameter of the fibers leads to high penetration of the dyes in the fibers.     

Application of anthocyanins as natural dye extracted from Brassica oleracea L. var. capitata f. rubra: dyeing studies of wool and silk fibres

Brassica oleracea L. var. capitata f. rubra (Red Cabbage) dye is composed mainly of natural pigment called anthocyanins used as a natural colourant. Wool and silk fibres were dyed with the aqueous extract obtained from red cabbage. The dyeing process was investigated and the combined effects of dyeing conditions on the colour yield parameter (K/S) were studied. Resulted fastness to wash, rubbing and light of the dyed fabrics were evaluated. Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD₅₎ of the residual effluent were measured. Best dyeing conditions were found to be: 50 g/100 mL, pH 2, 60 min and 100 °C, respectively, for the red cabbage weight, pH, dyeing duration and temperature. Good fastnesses properties were found in both cases: for wool and silk fabrics. It was found also that the calculated biodegradability ratio (COD/BOD₅) of the residual bath of dyeing wool and silk with red cabbage extract are lower than 1.5 which means that these baths are biodegradable.     

Dyeing wool and cotton fibres with acidic extract of Hibiscus rosa sinensis flower

Abstract

The focus of this work is to extract a natural dye for colouring camel wool as a substitute for synthetic dyes used in the Sadu House of Kuwait. Their target is to keep the tradition of tent and rug production natural in all its manifestations. Therefore, our task was to find an abundant source that provides a colour preferably red to purple. Hibiscus rosa sinensis (HRS) is an abundantly available plant in Kuwait that was explored for extraction of the red dye to colour camel wool permanently. The powdered petals of red flowers of HRS was extracted with 5% acetic acid which yielded a deep red colour that showed a great potential for woollen fibre dyeing. The use of mordants like alum and some metal salts manifested a wide range of fixed colours which intensified at 85 °C. The colours produced had excellent fastness and was accepted by the Sadu House.     

Development of colorimetric sensor array for discrimination of herbal medicine

Today, traditional systems of medicines (such as herbal distillates) become important resources for providing healthcare benefits. The ability to discriminate among closely similar herbal products is critical to ensure their efficacy. This article proposes a pattern-based recognition approach for the rapid discrimination of herbal distillates using a low-cost and sensitive colorimetric sensor array composed of 25 indicators. The color changes of the sensor exposed to the vapor of the herbal distillates can be monitored easily with an ordinary flatbed scanner. The digital representation of the array response was analyzed with hierarchical clustering analysis (HCA) and principal component analysis (PCA). Using new variable selection strategy, 6 indicators among the 25 employed indicators were selected as discriminant elements of the array. So, a complete discrimination (with 100% accuracy) of 46 herbal distillates was achieved. The proposed sensor represented a better resolution when analytes were placed in an oven at 85 °C for 45 min. This colorimetric sensor array demonstrates excellent potential for quality assurance/control applications of herbal distillates.     

Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash –SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.     

Spectrophotometric Determination of Hydrogen Peroxide Using Leucocrystal Violet in Micellar Medium

A simple and sensitive spectrophotometric method for the determination of hydrogen peroxide, based on the increase in color intensity of dye on addition of surfactant, is described. Hydrogen peroxide is first reacted with potassium iodide in acidic medium, in presence of ammonium molybdate to liberate iodine. The liberated iodine oxidizes leucocrystal violet to crystal violet having maximum absorbance at 593 nm. The color of the dye intensifies with the addition of the surfactant, cetyl pyridinium chloride though the absorption maximum remains the same. Beer's law is obeyed in the range 0.05–0.45 µg of hydrogen peroxide per 25 mL of final solution (0.002–0.018 µg mL^?1) with an excellent correlation coefficient (r = 0.9977). The proposed method has been successfully applied for the analysis of hydrogen peroxide in various food products and rainwater.     

Dyeing of cotton with thyme and pomegranate peel

Application of natural dyes for textiles is increasing due to awareness of environment, ecology, and pollution control. The purpose of this study is to determine the color, antimicrobial, and fastness properties of cotton fabrics dyed with thyme and pomegranate peel without a mordanting process. In this way, it was planned to avoid use of metallic mordants (heavy-metal salts) and prevent heavy-metal pollution for ecological production. Additionally, a variety of the most commonly used mordants, namely potassium aluminum sulfate, copper(II) sulfate, iron(II) sulfate, and tin(II) chloride, were used for mordanting of cotton fabrics in order to compare the differently mordanted and unmordanted dyed fabrics’ color efficiencies (K/S) and CIE L ^* a ^* b ^* color values. It was found that mordant type had an effect on color efficiency and the color coordinates of fabrics dyed with both thyme and pomegranate fruit peel. Moreover, the antimicrobial properties of the fabrics only dyed directly with thyme and pomegranate peel without any mordanting process were determined to demonstrate the usability of these natural dye sources without use of any mordanting agents. The obtained antimicrobial activities were compared with undyed samples. Undyed samples showed no antimicrobial activity, whereas significant antimicrobial activity was obtained after the dyeing procedure using thyme and pomegranate peel on unmordanted fabrics. Washing, rubbing, perspiration, and lightfastness properties of dyed fabrics were also evaluated. Thyme and pomegranate fruit peel as natural dye sources revealed sufficient results even for unmordanted samples.     

Quantitative determination of phosgene doses by reflectometric badge readout

Commercial phosgene dosimeter badges are lacking precise and sensitive analysis when used only by visual comparison to a color reference. To meet the discussed occupational standard set to 54 ppm min, objective quantification by reflectance measurement is proposed. At 573 nm, the pink dye (“Koenig´s salt”) formed at the membrane surface by reaction of phosgene, and aromatic amine shows a strict linear relationship in reflectance between doses of 10 and 300 ppm min. The detection limit is calculated to 29 ppm min.     

Production,Partial Characterization,and Use of a Red Biochrome Produced by <Emphasis Type="Italic">Serratia sakuensis</Emphasis> subsp. nov Strain KRED for Dyeing Natural Fibers

We have described a novel red biochrome, 514 Da in size, produced by solid-state cultivation of a bacterial isolate obtained from garden soil. The growth requirements of the isolate, the chemical characteristics of the biochrome produced, and the application of the biochrome in dying of silk, wool, and cotton fabrics have been studied. The biochrome obtained after 52 h of incubation and having a λ _max of 535 nm was used for dyeing the fabrics. We found that silk, wool, and cotton fabrics dyed with this new natural red compound have high color strength values and dye uptake along with good color fastness as well as antibacterial activity.     

Wheat straw lignin extraction with bio-based solvents using enabling technologies

Two bio-based solvents, natural deep eutectic solvents (NaDESs) and γ-valerolactone (GVL), have been used under microwave (MW), and ultrasound (US) irradiation to design an efficient and sustainable process for wheat straw delignification and have been compared with the traditional alkali procedure. Best delignification (45%) was achieved with a three-component NaDES (lactic acid/glycerol/choline chloride) under MW irradiation (at 120 °C in 30 min), with solid/liquid ratio of 1:50. A GVL/water mixture (8:2) also gave an efficient delignification (27%) under US irradiation (40 kHz, 200 W) at 50 °C for 60 min. Analytical pyrolysis (Py) coupled with GC/MS/FID, provides valuable information on the extracts’ chemical profile. DPPH and Folin–Ciocalteu tests highlighted the efficiency of MW- and US-assisted extraction as well as the extracts quality. The highest antioxidant activity for the NaDES extracts was obtained under US irradiation.     

Modified generalized kinetic model and degradation mechanistic pathways for catalytic oxidation of NBS dye in Fenton-like oxidation process

Rice husk was utilized as a silica source for the synthesis of mesoporous silica (MS), which was further used for the surface modification of iron oxide nanoparticles (IO-NPs) to form mesoporous silica-modified iron oxide nanoparticles (MSIO-NPs). IO-NPs and MSIO-NPs were characterized using FT-IR, XRD, X-ray photoelectron spectroscopy, vibrating sample magnetometry, nitrogen adsorption–desorption, TEM and dynamic light scattering analysis. The catalytic activity of MSIO-NPs was tested for degradation and mineralization of Nile blue sulphate dye (NBS) in Fenton-like oxidation process. The degradation efficiency and total organic carbon (TOC) removal of NBS dye onto MSIO-NPs was found to be 92.46 and 66.58%, respectively, after 20 min of reaction time using 5 mM of H₂O₂ concentration. Modified generalized kinetic model was developed for TOC removal of dye degradation onto MSIO-NPs, to account for oxidizable compounds, non-oxidizable compounds, and intermediate organic compounds. The intermediate products formed during degradation of NBS dye were detected by LC–MS experiment and ten fragments were identified based on mass to charge ratio (m/z). The mechanistic pathway for degradation of NBS dye onto MSIO-NPs has been proposed.     

Degradation kinetic (D100) of lycopene during the thermal treatment of concentrated tomato paste

Heat treatments can cause degradation in tomatoes of lycopene which has important antioxidant effects. No information about decimal reduction time (D₁₀₀) of lycopene is available. D-value is the time required at a given temperature to reduce 90% of the molecule. This study for the first time determine the kinetic of lycopene thermal degradation. The content was measured at regular intervals of pasteurization using canned tomato paste to determinate D value. Microbiological analysis was carried out to verify product stability after packaging. Yeasts, molds and lactic acid bacteria were determined. The pasteurization time allowed to observe a loss of the red color. Lycopene content, after an increase at 8 min, decreased at 32 min of pasteurization. D₁₀₀ value was calculated at 75 min; a diminution of 90% in lycopene content in the concentrated tomato paste was observed. Microbiological analysis confirmed the stability of products after 8 min of pasteurization.     

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds

This study compared phenolic contents and antioxidant activity in different organs of Acacia albida (leaves and bark) and focuses on identification of phenolic compounds of leaves by HPLC-DAD. The analysed organs exhibited differences in total polyphenol contents (100 and 59.5 mg GAE g^? 1 DW). Phenolic contents of leaves were two times higher than those in bark. Ethanolic extracts exhibited good antioxidant activities with IC₅₀ = 26 μg mL^? 1 for DPPH and EC₅₀ = 50 μg mL^? 1 for FRAP. Identification by HPLC-DAD revealed the presence of nine phenolic compounds known for their high antioxidant activity. The results suggested that this species can be used as source of natural antioxidants.     

Optimization of the oxalate catalyzed photoelectro-Fenton process under visible light for removal of Reactive Red 195 using a carbon paper cathode

The decolorization of Reactive Red 195 (RR195) by the oxalate catalyzed photoelectro-Fenton (PEF) process using carbon paper electrode as a cathode under visible light was studied. Comparison between electro-Fenton (EF), PEF, and PEF/oxalate processes for the removal of RR195 showed that color removal follows in decreasing order: PEF/oxalate > PEF > EF. Response surface methodology (RSM) was used to determine the effects of the four main independent parameters (initial dye, oxalate and Fe³⁺ concentrations, and reaction time) on decolorization efficiency. A high coefficient of determination value (R ² = 0.963) has resulted from the analysis of variance (ANOVA). The optimum values of the initial Fe³⁺ concentration, the initial amount of oxalate, the initial dye concentration, and the reaction time were found to be 0.3 mM, 0.6 mM, 20 mg/L, and 120 min, respectively. A high decolorization efficiency (>93 %) was experimentally obtained for RR195 under the established optimum conditions. The response surface plots were employed to establish the effect of experimental parameters on the decolorization efficiency. These results clearly indicated the success of RSM as a suitable method for optimizing the operating conditions. The mineralization of the dye was investigated by total organic carbon (TOC) measurement. 96.2 % mineralization of 50 mg/L RR195 was observed at 9 h.     

RP-HPLC method for estimation of sesamin in two Zanthoxylum species

Zanthoxylum naranjillo and Z. tingoassuiba (Rutaceae) are traditional herbal medicines with various biological activities including anti-inflammatory, analgesic, and antimalarial action. In this work, we have developed a simple HPLC-DAD method to quantify sesamin, a bioactive lignan present in Z. naranjillo and Z. tingoassuiba; egonol was the internal standard. According to the developed method, 11.07 ± 1.66, 8.69 ± 0.95, and 15.11 ± 0.72 µg/mL sesamin was present in the ethanol extract of Z. naranjillo leaves, in the methanol extract of Z. naranjillo leaves, and in the methanol extract of Z. tingoassuiba bark, respectively. The limits of detection and quantification were 0.32 and 1.06 µg/mL, respectively. The developed method can be easily applied during routine analysis of sesamin in these medicinal plants.     

Biological activity and LC-MS/MS profiling of extracts from the Australian medicinal plant Acacia ligulata (Fabaceae)

Acacia ligulata A.Cunn. ex Benth. (Fabaceae: Mimosoideae) is a native Australian plant used traditionally by Australian Aboriginal groups. This study was undertaken to investigate the bioactivity of A. ligulata extracts and to evaluate their chemical composition. Potential antibacterial, cytotoxic and enzyme inhibitory effects relevant to traditional medicinal and food uses of the species were examined and LC-MS/MS was performed to investigate the chemical composition. Antibacterial activity was observed for bark and leaf extracts with an MIC for the bark extract of 62.5 μg/mL against Streptococcus pyogenes. Pod extracts showed cytotoxic effects against cancer cells, with the highest activity against melanoma SK-MEL28 cells with IC₅₀ values between 40.8 and 80.6 μg/mL. Further, the leaf and pod extracts also inhibited α-amylase EC-3.2.1.1 and α-glucosidase EC-3.2.1.20 with IC₅₀ values between 9.7–34.8 and 12.6–64.3 μg/mL, respectively. The LC-MS/MS profiling indicated that several different saponins were present in the active extracts.     

Processing of β-Glucosidase–Silk Fibroin Nanoparticle Bioconjugates and Their Characteristics

Silk fibroin derived from Bombyx mori is a biomacromolecular protein with excellent biocompatibility. The aim of this work was to develop silk fibroin nanoparticles (SFNs) derived from the fibrous protein, which is a novel vector for enzyme modification in food processing. Silk fibroin was dissolved in highly concentrated CaCl₂ and subjected to lengthy desalting in water. The resulting liquid silk, which contained water-soluble polypeptides with molecular mass ranging from 10 to 200 kDa, and β-glucosidase were added rapidly into acetone. The β-glucosidase molecules were embedded into silk fibroin nanoparticles, forming β-glucosidase–silk fibroin nanoparticles (βG–SFNs) with a diameter of 50–150 nm. The enzyme activity of the βG–SFN bioconjugates was determined with p-nitrophenyl-β-d-glucoside as the substrate, and the optimum conditions for the preparation of βG–SFNs were investigated. The enzyme activity recovery of βG–SFNs was 59.2 % compared to the free enzyme (specific activity was 1 U mg^-1). The kinetic parameters of the βG–SFNs and the free β-glucosidase were the same. The βG–SFNs had good operational stability and could be used repeatedly. These results confirmed that silk protein nanoparticles were good carriers as bioconjugates for the modification of enzymes with potential value for research and development. The method used in this study has potential applications in food processing and the production of flavour agents.     

Adsorption characteristics of Titan yellow and Congo red on CoFe2O4 magnetic nanoparticles

This paper assesses the adsorption characteristics of Titan yellow and Congo red on CoFe₂O₄ magnetic nanoparticles. The adsorption behavior of Titan yellow and Congo red from aqueous solution onto CoFe₂O₄ magnetic nanoparticles has been determined by investigating the effects of pH, concentration of the dye, amount of adsorbent, contact time, ionic strength and temperature. Experimental results indicated that CoFe₂O₄ nanoparticles can remove more than 98 % of each dye under optimum operational conditions of a dosage of 15.0 mg CoFe₂O₄, pH 3.0, initial dye concentration of 22–140 mg L^?1, and contact times of 2.0 and 15.0 min for Congo red and Titan yellow, respectively. Langmuir and Freundlich isotherm models have been used to evaluate the ongoing adsorption kinetic equations. Regeneration of the saturated adsorbent was possible by NaCl/acetone solution as eluent. The maximum adsorption capacities were 200.0 and 212.8 mg dye per gram adsorbent for Congo red and Titan yellow, respectively. With the help of adsorption isotherm, thermodynamic parameters such as free energy, enthalpy and entropy have been calculated. On the basis of pseudo-first-order and pseudo-second-order kinetic equations, different kinetic parameters have been obtained.     

Assessment of operating parameters for photocatalytic degradation of a textile dye by Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>/TiO<Subscript>2</Subscript>/clinoptilolite nanocatalyst using Taguchi experimental design

In the current study, a nanophotocatalyst doped with of TiO₂ and Fe₂O₃ nanoparticles supported on Iranian clinoptilolite was synthesized and characterized by XRD, XRF, SEM, and EDX analyses. The results suggested the successful loading of TiO₂ and Fe₂O₃ nanoparticles onto the surface of clinoptilolite. The SEM images confirmed the average size of nanoparticles deposited on zeolite, which was about 20–40 nm. Furthermore, application of the synthesized photocatalyst in photocatalytic degradation of Acid Black 172 dye was studied using the Taguchi method and the chosen parameters were as follows: pH (2–7), dye concentration (50–200 mg/l), irradiation time (30–120 min), and catalyst dosage (0.5–1.5 g/l). The results indicate that dye concentration, pH, and irradiation time are respectively the most effective factors in these experiments while with the minimum dosage of the catalyst (0.5 g/l), up to 90 % removal efficiency could be achieved. The optimum value for each parameter was pH = 2, dye concentration = 50 mg/l, catalyst dosage = 1 g/l and irradiation time = 60 min, and the dye removal efficiency reached up to 100 % at these optimal conditions. Furthermore, after five-times recycling and reusing the catalyst, the efficiency of the photocatalytic degradation was reduced from 91.5 to 65.9 %, which is still an acceptable value.     

Effect of acid and alkali treatments of a forest waste,Pinus brutia cones,on adsorption efficiency of methyl green

The removal of methyl green (MG) dye from aqueous solutions using acid- or alkali-treated Pinus brutia cones (PBH and PBN) waste was investigated in this work. Adsorption removal of MG was conducted at natural pH, namely, 4.5 ± 0.10 for PBH and near 4.8 ± 0.10 for PBN. The pseudo-second-order model appeared to be the most appropriate to describe the adsorption process of MG on both PBN and PBH with a correlation coefficient R² > 0.999. Among the tested isotherm models, the Langmuir isotherm was found to be the most relevant to describe MG sorption onto modified P. brutia cones with a correlation factor R² > 0.999. The ionic strength (presence of other ions: Cl^?, Na⁺, and SO₄^2?) also influences the adsorption due to the change in the surface properties; it had a negative impact on the adsorption of MG on these two supports. A reduction of 68.5% of the adsorption capacity for an equilibrium dye concentration Ce of 30 mg/L was found for the PBH; while with PBN no significant influence of the ionic strength on adsorption was observed, especially in the presence of NaCl for dye concentrations superior to 120 mg L^?1.