Application of acid protease for eco-friendly pre-treatment of goat skin to improve antimicrobial finish using herbal natural extracts / Mona Vajpayee in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 6 (06/2023)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVIII, N° 6 (06/2023) . - p. 219-234 Titre : Application of acid protease for eco-friendly pre-treatment of goat skin to improve antimicrobial finish using herbal natural extracts Type de document : texte imprimé Auteurs : Mona Vajpayee, Auteur ; Mumal Singh, Auteur ; Hemen Dave, Auteur ; Lalita Ledwani, Auteur Année de publication : 2023 Article en page(s) : p. 219-234 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antimicrobiens Caractérisation Cuirs et peaux -- Finition Cuirs et peaux de chèvres Extraits de plantes Peptidases Traitement enzymatique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Due to its moisture retention capacity and huge surface area, leather is highly prone to microbial proliferation and biodeterioration; hence, leather products desired have an antimicrobial finish. In this study, acid protease enzyme pre-treatment of goat skin was utilized as an eco-friendly substitute for conventional wet-chemical processing. The treatment can impart the desired surface properties to improve the antimicrobial finish with natural extracts obtained from leaves of Azadirachta indica (Neem Tree), Ocimum sanctum (Holy Basil, Tulsi), and Camellia sinensis (Green Tea). The procedure was optimized for different process parameters, including enzyme concentration, pH, material to liquor ratio (MLR), treatment time, and temperature. The effect of the treatment on bulk and surface properties of the skin was characterized by weight loss analysis, X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Photoelectron Spectroscopy (XPS), Water contact angle measurement, Scanning Electron Microscopy (SEM) respectively. The effect of the enzymatic treatment on organoleptic properties and the mechanical strength of the skin was also studied. The enzymatic treatment resulted in weight loss, and removal of non-collagen components, thus opening the fibrous collagen matrix of the skin. Hence, the skin treated with acid protease enzyme provides better affinity and accessibility for phytoactive compounds from the natural extracts and better attachment by electrostatic attachment due to an increase in surface functional groups after the enzymatic treatment compared to untreated skin. The effectiveness of the antimicrobial finish was measured as a zone of inhibition and with a modified Hohenstein test against test microorganisms E. coli and S. aureus.Azadirachta indica (Neem Tree) extract showed the highest inhibitory activity (97%) against E. coli, while the Ocimum sanctum (Holy Basil, Tulsi) extract exhibited the highest inhibitory activity (95%) against S. aureus. Note de contenu : - EXPERIMENTAL WORK : Material - Enzymatic treatment of goat skin samples with acid protease - Characterization - Preparation of antimicrobial extract and antimicrobial finishing of goat skins - RESULTS AND DISCUSSION : Weight loss percentage - ATR-FTIR analysis - XPS analysis - TG and DTG analysis - XRD analysis - SEM analysis - Water contact angle measurement - Effect of the enzymatic treatment on mechanical strength and organoleptic properties - Effect of the enzymatic treatment on non-collagen components of the goat skin - Identification of active constituents of the natural extracts - Antimicrobial activity - Table 1 : XRD parameter of untreated and enzymatic treated goat skin - Table 2 : Results of mechanical strength analysis for untreated and enzyme-treated goat skin - Table 3 : Quantitative analysis of non-collagen skin components of the skin - Table 4 : Zone of inhibition (cm) obtained for untreated skin finished with the natural extracts (UT+EX) and the enzyme-treated skin finished with the natural extracts (ET+EX) - Table 5 : Percentage reduction of bacteria obtained by modified Hohenstein test for the enzyme-treated and untreated skin samples finished with the 5% w/v natural extracts; UT = Untreated skin, ET = skin with the enzymatic treatment DOI : https://doi.org/10.34314/jalca.v118i6.7588 En ligne : https://drive.google.com/file/d/1N60QBt1TbAhe30QdkSbZ-D1G85Sbw_1P/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39479 [article]

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Determining the effect of enzymatic pretreatment on the low temperature dyeability of polyamide fabrics in COLORATION TECHNOLOGY, Vol. 139, N° 1 (02/2023)  

[article]  inCOLORATION TECHNOLOGY > Vol. 139, N° 1 (02/2023) . - p. 109-116 Titre : Determining the effect of enzymatic pretreatment on the low temperature dyeability of polyamide fabrics Type de document : texte imprimé Année de publication : 2023 Article en page(s) : p. 109-116 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Basses températures Colorants -- Adsorption Colorants métalliques Complexes métalliques Elasthanne Fourier, Spectroscopie infrarouge à transformée de Microscopie électronique à balayage Polyamide 6 Résistance à l'abrasion Résistance à l'éclatement Résistance au lavage Solidité de la couleur Teinture -- Fibres textiles synthétiques Traitement enzymatique Tricot Index. décimale : 667.3 Teinture et impression des tissus Résumé : In this study, by pretreating polyamide 6/elastane knitted fabrics with serine-type protease enzyme, the aim was to reduce dyeing temperatures. It is known that the elasticity of elastane fibres is damaged in dyeing at high temperatures. On the other hand, to enable efficient dyeing, it is necessary to use boiling temperatures in synthetic fibres such as polyamide, or even mild high temperature conditions, to support more uniform dyeing. Protease enzymes are enzymes that hydrolyse amide bonds, and consequently, new amine and carboxyl groups are released in fibre macromolecules, resulting in an increase in the functional group content to which anionic dyes can bind. In this study, to compensate for the loss of colour yield caused by lowering the dyeing temperature, an increase in the functional groups was provided by enzymatic pretreatment. For this purpose, the fabrics were pretreated with a commercial serine-type protease enzyme then dyed with 1:2 metal complex dyes at different temperatures. The effects of enzymatic pretreatment on colour, fastness, fibre surface characteristics and fabric strength were investigated. Note de contenu : - Enzymatic pretreatment - Determination of dye uptake values - Determination of colour yield and CIELab values - Determination of colour fastness to washing - Determination of colour fastness to rubbing - Bursting strength - Fourier Transform-infrared spectroscopy analysis - Scanning electron microscopy analysis - Table 1 : Analysis of variance results related to the effects of dyeing temperature, enzymatic process and dye type on the colour yield - Table 2 : Scanning electron microscopy photographs of enzymatically treated and untreated samples (x 2000 magnification) - Table 3 : Washing and water fastness values of dyeing - Table 4 : Acidic and alkali perspiration fastness values of dyeing - Table 5 : Dry and wet rubbing fastness values of dyeing DOI : https://doi.org/10.1111/cote.12637 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12637 Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39209 [article]

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Effect of processing conditions on the rheological and mechanical properties of composites based on a PBS matrix and enzymatically treated date palm fibers / Rania Chaari in INTERNATIONAL POLYMER PROCESSING, Vol. 38, N° 1 (2023)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 38, N° 1 (2023) . - p. 19-29 Titre : Effect of processing conditions on the rheological and mechanical properties of composites based on a PBS matrix and enzymatically treated date palm fibers Type de document : texte imprimé Auteurs : Rania Chaari, Auteur ; Fatma Kharrat, Auteur ; Mohamed Khlif, Auteur ; Chedly Bradai, Auteur ; Catherine Lacoste, Auteur ; Philippe Dony, Auteur Année de publication : 2023 Article en page(s) : p. 19-29 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse morphologique Caractérisation Composites à fibres végétales Composites à fibres végétales -- Propriétés mécaniques Essais dynamiques Fibres de palmier dattier Mélange Polybutylène succinate Résistance thermique Rhéologie Traitement enzymatique Index. décimale : 668.4 Plastiques, vinyles Résumé : The rheological properties of biocomposites can change depending on the polymer, fiber type, fiber size and processing conditions. In this work, biodegradable PBS composites filled with raw and enzymatically treated date palm fibers were processed using an internal mixer. The influence of the processing conditions, namely filler concentration, rotor of the mixer rotational speed, as well as the type of the enzymatic fiber treatment on PBS (Poly Butylene Succinate)/date palm fiber composites were studied by measuring the torque and the temperature in real time during melt processing. A rheological analysis was also carried out by performing time and multi-wave-frequency sweeps. It was found that the stabilization torque increased with increasing fiber loading and rotor rotational speed, indicating a higher viscosity. An enhancement of the melting process occurred with modified fibers, which was explained by the decrease in the fiber diameter, denoting cellulose micro-fibrils separation by enzymes action. These composites were characterized by a better thermal resistance and mechanical stiffness compared to those based on raw fibers at the same loading rate. Note de contenu : - MATERIALS : Fiber modification - A fiber size analysis - Manufacturing of the PBS-DPF composites - Morphology analysis - Torque and temperature of the composites during mixing at different operating conditions - Rheological analysis - Tensile tests - RESULTS AND DISCUSSION : Fiber size distribution - Morphological characterization - Torque and temperature of the composites in the internal mixer at different operating conditions - Rheological characterization - Tensile characterization DOI : https://doi.org/10.1515/ipp-2022-4251 En ligne : https://drive.google.com/file/d/182C-yWRVGzF6k6TrrMUdFw-y8bmvqvIo/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39191 [article]

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Study on changes of collagen fibril structure in pigskin tissue after enzyme / Wang Yingmei in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 89, N° 2 (03-04/2005)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 89, N° 2 (03-04/2005) . - p. 47-56 Titre : Study on changes of collagen fibril structure in pigskin tissue after enzyme Type de document : texte imprimé Auteurs : Wang Yingmei, Auteur ; Li Zhiqiang, Auteur ; Chen Min, Auteur ; Cheng Haiming, Auteur ; Liao Longli, Auteur Année de publication : 2005 Article en page(s) : p. 47-56 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Collagène -- Analyse Cuirs et peaux -- Analyse Fibrilles de collagène La fibrille de collagène est une structure constituée d'un assemblage de fibres de tropocollagène (assemblage de 3 protéines de collagène alpha (alpha 1 - alpha 1 - alpha 2) en une hélice droite. Microscopie à sonde à balayage Microscopie électronique en transmission Traitement enzymatique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Transmission Electron Microscopy (TEM) and Scanning Probe Microscopy (SPM) have been employed to study changes of collagen’s fibril fine structure in pigskin tissue after enzyme treatment. The 3D-structure of fibrils in enzyme treated pigskin tissue was analyzed both qualitatively and quantitatively. The work yielded information about the most typical changes in fibrils and sub-fibrils under enzyme treatment and the relationship between enzymatic depilation and the mechanical characteristics of finished leather. Note de contenu : - MATERIALS AND METHODS : Samples - RESULTS : Transmission Electron Microscopy (TEM) - Scanning Probe Microscopy (SPM) En ligne : https://drive.google.com/file/d/1IvbLgtkbtgCV4rkrzU8gkgfeZv82uQ5C/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39591 [article]

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Ultrasound-assisted enzymatic scouring of jute optimised by response surface methodology and its natural dyeing / Harshal Patil in COLORATION TECHNOLOGY, Vol. 139, N° 1 (02/2023)  

[article]  inCOLORATION TECHNOLOGY > Vol. 139, N° 1 (02/2023) . - p. 97-108 Titre : Ultrasound-assisted enzymatic scouring of jute optimised by response surface methodology and its natural dyeing Type de document : texte imprimé Auteurs : Harshal Patil, Auteur ; Sahil Mudaliar, Auteur ; Ashok Athalye, Auteur Année de publication : 2023 Article en page(s) : p. 97-108 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Décapage Fibres textiles -- Lavage Jute et constituants Le jute est une plante herbacée de la famille des Malvacées, cultivée dans les régions tropicales pour ses fibres. Jute est aussi le nom donné à ces fibres textiles, appelées aussi chanvre de Calcutta. Nom scientifique : Corchorus capsularis L., famille des Malvacées, sous-famille des Grewioideae ; la classification classique le situe dans la famille des Tiliacées. Une plante voisine, Corchorus olitorius L., la corète potagère, est aussi utilisée aux mêmes fins. Surfaces de réponse (statistique) Teinture -- Fibres textiles Traitement enzymatique Ultrasons Index. décimale : 667.3 Teinture et impression des tissus Résumé : India is the largest producer of jute in the world and the use of this natural fibre in various value-added applications is gaining momentum. The use of white biotechnology involving enzymes for the efficient processing of jute is considered to boost its productivity. The present investigation deals with the pretreatment of jute by using ultrasound-assisted enzymatic scouring followed by bleaching and dyeing. The process showed optimum removal of impurities and improved water absorption capacity with minimal damage to fibre tensile strength. The process parameters and conditions were determined by response surface methodology, where weight loss of jute was kept as the main response. The optimised recipe obtained was 2.8% enzyme concentration, 1 g/L wetting agent at 55°C for 10 minutes at an ultrasound frequency of 40 kHz. The optimised recipe was compared with conventional high-temperature long-duration enzymatic scouring and was found to have an equal performance. Further, the scoured jute was dyed with a natural dye extracted from sappan wood and madder. Fourier Transform-infrared analysis was used for characterisation. The wash and light fastness of dyed jute yarn were evaluated and found to meet the industry norms. Note de contenu : - Optimisation of ultrasonic enzymatic scouring conditions using response surface methodology - Regression analysis - Response surface plot - Optimisation of responses - Pretreatment performance : Effect of pretreatment on the properties of jute yarn - Dyeing performance : Effect of pretreatments on the natural dyeing performance of jute yarn - Structural characteristics of scoured jute - Table 1 : Process parameters with range for the ultrasonic enzymatic scouring of jute yarn - Table 2 : Design matrix of experiments for the enzymatic scouring of jute - Table 3 : ANOVA model results of ultrasonic enzymatic scouring for jute yarn - Table 4 : Ranges of process parameters and their outputs - Table 5 : Pretreatment performance of jute yarn enzymatic scouring with ultrasound and conventional methods - Table 6 : Pictures of scoured, bleached and dyed jute yarn - Table 7 : Dyeing performance of jute yarn enzymatic scouring with ultrasound and conventional methods - Table 8 : Fastness performance of jute yarn enzymatic scouring with ultrasound and conventional methods DOI : https://doi.org/10.1111/cote.12638 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12638 Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39208 [article]

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