A comparative evaluation of the action of savinase and papain to the cutinase-pretreated wool

The enzymatic anti-felting of wool with proteases is a promising eco-friendly alternative to the chlorine-Hercosett process. However, protease molecules could penetrate into the interior of fibers during wool processing, easily causing unacceptable damages. In this paper, the action and mechanism of two protease treatments, i.e. Savinase and papain treatments on the properties of cutinase-pretreated wool fabrics were investigated and compared. The results showed that the anti-felting processing based on cutinase and papain treatments seemed more effective. When the percentages of weight loss for the combined treated fabrics were similar, the improvement of wettability and shrink-resistance for the cutinase-papain treated sample was more remarkable, the strength loss was also lower than that of the sample treated with cutinase and Savinase consecutively. The mechanisms of the two different combined treatments were further evaluated by Allwöden’s reaction and amino acid analysis. The comprehensive comparison proved that the hydrolytic activity of papain towards the scale exocuticle of wool was a bit higher than that of Savinase and less degradation of the interior of fibers occurred during the cutinasepapain treatment.     

The combined use of cutinase,keratinase and protease treatments for wool bio-antifelting

A combined treatment method of cutinase, keratinase, and protease was applied in the wool processing to modify the wool properties. The results demonstrated that individual protease treatment did not obviously improve the wettability and anti-felting property of wool fabrics. The combined process of cutinase and protease seemed more efficient than the keratinase-protease method, the obtained wettability and anti-felting ability of wool fabric were more encouraging. The combined use of cutinase, keratinase, and protease treatments endowed wool with more satisfactory properties compared to other methods. The contact angle of the protease-treated wool fabric reduced to 66 ° and the area shrinkage decreased to 5.2 % with an acceptable strength loss of 14 %. Reaction mechanism of the three-step enzymatic process was proposed in this paper. The data from amino acid analysis revealed the cooperative actions of cutinase, keratinase, and protease treatments during the combined enzymatic processing.     

Effect of pineapple protease on the characteristics of protein fibers

A pineapple protease, bromelain, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the pineapple protease was about 60 °C at pH 7. The wool and silk were treated with the protease extracted from a pineapple and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The protease treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of protease-treated fibers were observed by microscopy.     

The effect of ultrasonication on the micro-splitting of wool fiber

In this study, normal and dichlorodicyanuric acid (DCCA)-treated wool slivers were ultrasonicated in formic acid aqueous solutions. The effect of the ultrasonication condition on the wool fiber splitting was examined and the mechanism of the splitting by ultrasonication in formic acid was elucidated. No wool fiber splitting occurred at formic acid content up to 70 %, but the fiber splitting accelerated as the formic acid content increased from 75 %. Although no fiber splitting occurred up to 450W ultrasonic power, the degree of splitting increased significantly with increasing ultrasonic power above 450W. The wool fiber splitting by ultrasonication was heterogeneous and FE-SEM observations revealed a three-step splitting process: 1) full removal of scale, 2) removal of cell membrane complex (CMC), and 3) fiber splitting. A comparison of the fiber splitting of normal and DCCA-treated wool revealed that the scale of the ultrasonication-treated wool was removed by peeling off rather than by dissolution.     

Effects of low temperature plasma on wool and wool/nylon blend dyed fabrics

Knitted wool and wool/nylon blend dyed fabrics were treated with low temperature plasma (LTP) to achieve optimum shrink-resistance without impairing surface topography, colour or fastness to washing of the fabrics. As LTP tends to impair handle of the fabrics, both wool and wool/nylon blend fabrics were submitted to industrial softening and/or biopolymer treatments after LTP treatment, leading to hydrophilic wool and wool/nylon blend fabrics with improved shrink-resistance without any colour changes and good fastness to washing. The results obtained were compared with those obtained by an industrial shrink-resist treatment.     

The comparison of the effect of enzyme, peroxide, plasma and chitosan processes on wool fabrics and evaluation for antimicrobial activity

Pretreated (enzymatic and enzymatic+hydrogen peroxide) knitted wool fabrics were treated with atmospheric argon and air plasma to improve their adsorption capacity. After plasma treatments chitosan solution was applied to have antimicrobial effect on wool fabrics. The treated fabrics were evaluated in terms of washing stability as well as antimicrobial activity. The surface morphology was characterised by SEM images and FTIR analysis. From the results it was observed that atmospheric plasma treatment had an etching effect and increased the functionality of a wool surface. Atmospheric plasma treatment also enhanced the adhesion of chitosan to the surface and improved the antimicrobial activity of the wool sample. Argon was found to be more effective than air, since argon radicals played an important role in killing and removing bacteria. No significant difference in washing durability was observed in terms of plasma treatments. The samples of combined pretreatment processes had good washing durability even after 10 washing cycle. From the SEM images it was observed that combination of plasma and the other pre-treatment processes gave less damage than only one process.     

Surface characterization of low temperature plasma treated wool fiber

Previous investigation results revealed that after the Low Temperature Plasma (LTP) treatment, the hydrophilicity of wool fiber was improved significantly. Such improvement enhances the wool dyeing and finishing processes which might be due to the changes of the wool surface to a more reactive one. In this paper, wool fibers were treated with LTP with different gases, namely, oxygen, nitrogen and gas mixture (25 % hydrogen/75 % nitrogen). Investigations showed that chemical composition of wool fiber surface varied differently with the different plasma gas used. The surface chemical composition of the different LTP-treated wool fibers was evaluated with different characterization methods, namely FTIR-ATR, XPS and saturated adsorption value. The experimental results were thoroughly discussed.     

Study of antimicrobial activity of aloevera, chitosan, and curcumin on cotton, wool, and rabbit hair

Aloevera, chitosan, and curcumin were applied in alone and in combination with each others on cotton, wool and rabbit hair by exhaustion method for the assessment of their antimicrobial activity. The antimicrobial activity of these natural ingredients was better in peroxide treated cotton, formic acid treated wool/rabbit hair fibrous substrates than their corresponding intact ones. Aloevera shown better antimicrobial activity than chitosan and curcumin when applied alone and its antimicrobial activity was enhanced by addition of both chitosan and curcumin. The application of aloevera+chitosan+curcumin combination on peroxide treated cotton and formic acid treated wool/rabbit hair fibrous substrate was fast up to twenty five washing cycles.     

New thiol-disulfide exchangers as anti-setting agents for wool fabric during dyeing

Setting of wool fabrics during dyeing is an acute industrial dilemma facing most of wool dyers. Therefore, wool fabrics were dyed with acid, basic, as well as mono- and bi-functional reactive dyes in the presence of selected aliphatic and aromatic anti-setting agents; namely 3,3-dithiodipropionic acid (DTDPA), dithiodiglycolic acid (DTDGA), 5,5-dithio-bis(2-nitrobenzoic acid) (DTBNBA), dithiodibutyric acid (DTDBA), 2,2-dithiodisalicylic acid (DTDSA), and 6,6-dithiodinicotinic acid (DTDNA). The effect of incorporating the said thiol/disulfide-exchangers into the dyeing bath of wool on its dimensional stability was assessed. The influence of the proposed anti-setting agents on the dyeability of wool with the said reactive dyes was monitored. The alteration in the chemical composition of the dyed fabrics was monitored by determining their sulfur and nitrogen contents, cysteine content, and the solubility degree in alkaline solution. The used reagents were found to be effective in stabilization of wool during dyeing with reactive dyes to different extents depending on the nature of the used anti-setting agent. Limited change in the chemical composition of the dyed samples was monitored without affecting their dyeability with the said dyes. The mechanism of interaction of these reagents with wool fabrics during dyeing was proposed.     

Effect of enzymatic treatment on the dyeing properties of protein wool fibers

Two proteolytic enzymes were used as auxiliaries in the dyeing of wool fabrics with acid dyes. The effect of the enzymes on dye exhaustion (%E) and dye uptake (K/S) was studied at 70, 85, and 98 °C and compared to the corresponding values obtained for the control samples which were dyed without enzymes under the same conditions. Two commercially available dyeing auxiliaries commonly used for the dyeing of wool at low temperatures were also used under the same conditions and compared with the dyeings made with and without enzymes. Treatment with transglutaminase was done in order to compensate the damaging effects of protease. The study shows that the enzymes could be used as auxiliaries in the dyeing of wool at lower temperatures.     

Effect of peroxide and softness modification on properties of ramie fiber

Ramie fiber is one of the natural cellulose fibers that have undergone rapid development due to its good performance. This study confirmed that hydrogen peroxide and isopropyl alcohol can be used as very efficient agents for simultaneous removal of non-cellulosic substances and improvement of ramie fiber properties. The factors influencing the properties of modified fiber with combined chemicals were investigated. Optimum treatment conditions were achieved at 85 °C, 60 min, pH 11.0, hydrogen peroxide concentration 7 %, and isopropyl alcohol concentration 4 %. SEM, XRD, and FT-IR were used to elucidate the effects of preparation and modification. Results showed that fiber preparation and chemical modification process in the same bath solution could successfully remove most of the gummy materials. The treated fibers demonstrated improved softness, elongation, and fineness properties as compared to the alkali or peroxide method.     

Transglutaminase treatment for improving wool fabric properties

The microbial transglutaminase (mTGase) is used as a bio-catalyst to repair the wool damages caused by chemical or enzymatic treatments. In this paper, the effect of mTGase on the degree of yarn strength, area shrinkage, wettability, and the dyeing properties of wool was investigated. Through mTGase treatment, the yarn strength was improved about 22.2 %. The knitted wool fabrics treated with mTGase after pretreatment of H₂O₂ and protease displayed 7.5 % of area shrinkage and about 22.3 % recovery in tensile strength when compared with those treated without mTGase. Also, mTGase treatment could improve the wettability and dyeing properties of wool fabrics. With the increase of mTGase concentration, the initial dye exhaustion increased significantly and the time to reach the dyeing equilibrium was shortened. It was evident that the improvement of dyeing properties was closely related to the improvement of wettability performance of wool fabric by using transglutaminase.     

Development of durable shrink-resist coating of wool with sol-gel polymer processing

Knitted wool fabric was pre-treated with the serine type protease, Esperase 8.0L (EC3.4.21.62), and sodium sulphite followed by an immersion treatment with a sol-gel hybrid polymer. To enhance the durability of the sol-gel treatment on wool, one of two different alkoxysilanes containing coupling epoxy or mercapto groups were added to the sol-gel hybrid. The combination of protease treatment with an immersion sol-gel treatment achieved wool fabric that was lightweight with a soft handle and had combined shrink-resistance and hydrophobic properties without fibre discoloration. The addition of an alkoxysilane with a mercapto coupling group within the sol-gel hybrid gave better performance than using an alkoxysilane with an epoxy coupling group in terms of polymer uptake, fabric shrink resistance, whiteness and durability to washing.     

Study on the natural dyeing of wool modified with enzyme

In this study, the natural pigment from sappan was used for the dyeing of wool fabrics after treatment with the protease and transglutaminase. The influences of protease and transglutaminase on the UV/visible absorption spectrum of aqueous extract of sappan were studied. The enzymatic modified wool was compared with non-modified wool in K/S value and fastness after direct dyeing and mordant dyeing. It was shown that protease and transglutaminase made the absorbance at the λ _max 540 nm in visible region increase. It suggested that there might be some interaction between the enzymes and sappan dye and the residual enzyme on wool fabric might affect the color of following dyeing. Compared to untreated wool, treatments with protease and transglutaminase enhance K/S value of wool dyed subsequently with sappan. Modification of protease led to some decrease in wet rubbing fastness, whereas transglutaminase had almost no influence on rubbing fastness. Enzymatic treatments have no influence on the washing fastness for samples dyed with sappan.     

Improvement in gluten-free rice bread quality by protease treatment

The wide prevalence of gluten-related disorders has led to increase in the demand for gluten-free foods. Rice is a gluten-free and less allergenic cereal. However, bread made from rice flour, i.e., gluten-free rice bread, is generally of poor quality because rice flour cannot develop a network with gluten-like properties. In this study, we investigated the effects of protease treatment on gluten-free rice to improve the quality of its bread. Bread treated with a commercial protease from Bacillus stearothermophilus (thermoase) was of higher quality, i.e., good crumb appearance, high volume, and soft texture, depending on the amount of enzyme added. Rice proteins in the protease-treated bread were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed that glutelins and prolamins were hardly digested by thermoase in comparison with other proteins. Scanning electron microscopy revealed that many cellular structures were formed in the thermoase-treated bread; however, these structures were rare in the untreated control. Bread crumb color was not affected by the treatment. The staling rate was much lower for the thermoase-treated bread than for the control. These results indicate that thermoase treatment can be successfully used to improve the quality of gluten-free rice bread by partial digestion of rice proteins.     

Dyeing behavior of low temperature plasma treated wool

In this paper, the effects of low temperature plasma (LTP) treatment on the dyeing properties of the wool fiber were studied. The wool fibers were treated with oxygen plasma and three types of dye that commonly used for wool dyeing, namely: (i) acid dye, (ii) chrome dye and (iii) reactive dye, were used in the dyeing process. For acid dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased but the final dyeing exhaustion equilibrium did not show any significant change. For chrome dyeing, the dyeing rate of the LTP-treated wool fiber was also increased but the final dyeing exhaustion equilibrium was only increased to a small extent. In addition, the rate of afterchroming process was similar to the chrome dyeing process. For the reactive dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased and also the final dyeing exhaustion equilibrium was increased significantly. As a result, it could conclude that the LTP treatment could improve the dyeing behavior of wool fiber in different dyeing systems.     

Oxidation of commercial (α-type) zein with hydrogen peroxide improves its hydration and dramatically increases dough extensibility even below its glass transition temperature

To improve the rheological properties of zein doughs, α-type zein and zein-starch doughs were prepared with the oxidising agents, hydrogen peroxide and peroxidase, which strengthen gluten-based doughs by cross-linking. Hydrogen peroxide and peroxidase increased zein dough extensibility compared to preparation with water. Hydrogen peroxide prepared zein doughs were extensible and cohesive below zein’s glass transition temperature. The doughs did not exude water and maintained flexibility when stored. Confocal laser scanning microscopy revealed that in zein-starch doughs prepared with hydrogen peroxide a thin continuous zein matrix was formed around the starch granules, whereas doughs prepared with water exhibited clumps of granules. SDS-PAGE of zein doughs and films treated with the oxidising agents showed no evidence of zein polymerisation, nor did Fourier transform infrared spectrometry reveal any significant changes in secondary structure. Further, hydrogen peroxide treatment did not increase zein film glass transition temperature, but it did increase transition enthalpy, and film water uptake increased with hydrogen peroxide concentration. The greatly increased extensibility of hydrogen peroxide prepared zein doughs and their improved water-holding are not due to oxidative cross-linking. It is proposed that the effects are primarily due to hydroxylation of amino acid aliphatic side chains, improving hydration through hydrogen bonding.     

A bio-antifelting agent based on waterborne polyurethane and keratin polypeptides extracted by protease from waste wool

A bio-composite made from keratin polypeptides and waterborne polyurethane was firstly employed as a bioantifelting agent for wool fabric. The keratin polypeptides, extracted from the waste wool fibers with the protease Esperase8.0L, possessed 5271 weight-average molecular weight. The bio-composites containing different contents of keratin polypeptides were applied for wool anti-felting treatment by a pad-dry-cure process. The results indicated that with increasing content of keratin polypeptides from 0 to 6 wt.%, the area-shrinking rate of the treated wool fabrics was decreased from 4.55 % to 0.47 %, respectively. The warp and weft tensile strength at break of the fabric was increased by 8 % and 12 %, respectively and reduced by about 55 % consumption of waterborne polyurethane. The film of bio-composites had more excellent thermal stability, higher mechanical property in elasticity, and better cytocompatibility compared with the pure waterborne polyurethane film.     

Ameliorative Effects of Hydrogen Peroxide,Ascorbate and Dehydroascorbate in <Emphasis Type="Italic">Solanum Tuberosum</Emphasis> Infected by Phytoplasma

Phytoplasmal infections cause loss in yield, quality and germination of tubers. Hydrogen peroxide and antioxidants such as ascorbic acid and dehydroascorbate are implicated in signaling against stress. The effects of these chemicals on minituber yield, sprouting and starch content were evaluated in plants testing positive for phytoplasma. Without chemical treatment, positive plants showed significant reductions in leaf pigments, tuber weights and starch contents, compared to uninfected controls, and had more minitubers though fewer sprouted. Hydrogen peroxide and antioxidant treatments of positive plants significantly reduced the number of minitubers, while enhancing their weights and starch contents, and increased the percentage of sprouting minitubers, while leaf pigment content also increased. This research demonstrates potential benefits of hydrogen peroxide and antioxidants in enhancing the yield and quality of tubers not destined for seed in phytoplasma positive plants.     

Bleaching of Hemp (<Emphasis Type="Italic">Cannabis Sativa</Emphasis> L.) Fibers with Peracetic Acid for Textiles Industry Purposes

Hemp plant exhibits various eco-friendly properties and hemp fiber processing does not cause environmental damage, however, it is known that most chemical operations have a risk to interrupt a sustainable production. As stated in several studies, peracetic acid is an important environmental friendly bleaching agent when compared to its conventional competitors. In this study, hemp fabric was bleached with peracetic acid with exhaustion and padding methods. The effects of temperature, pH, process time, concentration on whiteness values were determined. The influences of bleaching processes were investigated via instrumental and imaging methods. Physical properties of the treated fibers were also tested. Besides peracetic acid, hydrogen peroxide bleaching was carried out for comparison. COD values of bleaching effluents were analyzed for selected samples. Higher whiteness values were obtained with exhaustion bleachings than pad-batch bleachings. Quite high whiteness values (up to 68.13 Stensby whiteness index) attained in peracetic acid without significant fiber damage.