Impact of microwave irradiation on vegetable tanning / Jiacheng Wu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 102, N° 1 (01-02/2018)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 102, N° 1 (01-02/2018) . - p. 7-11 Titre : Impact of microwave irradiation on vegetable tanning Type de document : texte imprimé Auteurs : Jiacheng Wu, Auteur ; Zhiwen Fan, Auteur ; Jinwei Zhang, Auteur ; Yao Wang, Auteur ; Wuyong Chen, Auteur Année de publication : 2018 Article en page(s) : p. 7-11 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse thermique Chromatographie en phase liquide à hautes performances Chromatographie sur gel Cuirs et peaux Micro-ondes Pénétration (physique) Phénols Stabilité thermique Tannage végétal Tannage végétal -- Analyse Température de retrait Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : As a novel, mild, environmentally friendly and efficient thermal technology, microwave is freely used in many fields. Hence, an attempt has been made to apply the microwave in vegetable tanning to accelerate tanning reaction and improve the performance of the leather. In this work, the bonding properties of tannin extracts under microwave irradiation heating (MIH) ware investigated cornpared with water bath heating (WBH). Thermal performance of the leather treated under MIH was characterized by the shrinkage temperature and differential scanning calorimeter. The composition and properties of tanning liquors were analyzed by ultraviolet visible absorption spectroscopy, high performance liquid chromatography and gel permeation chrornatography. The results showed that the thermal stability of leather was improved and the shrinkage temperature of the leather increased about 1°C under MIH. Compared with a conventional tanning, the çomposition and properties of the liquids changed under MIH, for example, the content of rnacromoIecules and total phenolics content reduced. Furthermore, the number-average molecular weight of tanning liquid also decreased. The results indicated that MIH could promote the penetration of tannin extracts and combination between tannins and collagen. Note de contenu : - EXPERIMENTAL PROCEDURES : Tanning processes - Determination of total phenolics content (TPC) - Analysis of remaining tan liquor (RTL) - Analysis of thermal properties - RESULTS AND DISCUSSION : Tanning process - Thermal properties - Composition of RTL - FIGURES : 1. The penetration depth of tannins - 2. DSC curves of the leather - HPLC of RTL - 4. GPC of RTL - TABLES : 1. UV absorbance of TL - 2. Ts of the leather En ligne : https://drive.google.com/file/d/1gsvLa8G3sgkFgWqEA67v8dqHSjuJbYSM/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30008 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
19605	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Interaction of enzymes and hide/leather based on microwave use / Jiacheng Wu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 102, N° 4 (07-08/2018)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 102, N° 4 (07-08/2018) . - p. 204-209 Titre : Interaction of enzymes and hide/leather based on microwave use Type de document : texte imprimé Auteurs : Jiacheng Wu, Auteur ; Ting Sun, Auteur ; Jinwei Zhang, Auteur ; Wuyong Chen, Auteur Année de publication : 2018 Article en page(s) : p. 204-209 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Confitage Le confitage est une action biochimique effectuée au moyen de produits enzymatiques, qui a pour but de dégrader les fibres élastiques, contribuant ainsi à augmenter la souplesse du cuir. En outre, les enzymes complètent la dégradation des résidus épidermiques, donnant ainsi une fleur plus propre et plus lisse. Cuirs et peaux de chèvres Enzymes Une enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes. Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie. Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums. Epilage enzymatique Micro-ondes Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : With the characteristics of high efficiency, specificity and mild reaction conditions, enzymes are able to catalyse many biochemical reactions. Hence, they are widely used in the soaking, unhairing, degreasing and bating processes in the leather industry. At present, there are a lot of studies on the interaction laws between protease and collagen under conventional water bath heating ; however, under microwave irradiation with both thermal and non-thermal effects, corresponding research has not yet been reported. In this work, enzymatic unhairing (EU), bating (EB) and wet-blue leather treating (ET) processes were investigated under microwave irradiation heating compared with water bath heating. Hydroxyproline concentration and chrome content were analysed by ultraviolet-visible absorption spectroscopy. The grain of the sample was observed with a microscope. Thermal performance and physical and mechanical properties of the collagen composites was characterised by the shrinkage temperature, softness, tensile and tear strength, respectively. The results showed thât microwave could increase EU and EB rates, EU was completed 2 hours earlier and the end of EB was 1 hour in advance. After microwave irradiation, the grain of the skin or leather had better flatness and softness. It also promoted enzymatic proteolysis, in which the hydroxyproline concentration in EB and ET was decreased by 0.26 mg/L and 0.12mg/L, respectively. In addition, microwave use lowered the removal of chromium in ET, and the chrome content was reduced by 11.96mg/L. Quite a long exposure to microwave irradiation would inactivate enzymes, slightly weakening the tensile and tear strength of the leather. The results indicated that microwave treatment could promote the leather manufacturing process and improve the performance of collagen composites, which may lay a foundation for the application of microwaves in the leather industry. Note de contenu : - EXPERIMENTAL PROCEDURES : materials - Enzymatic unhairing (EU) process - Enzymatic bating (EB) process - Enzymatic treatment (ET) of wet-blue goat leather - RESULTS AND DISCUSSION : Microwave effect on EU - Microwave effect on EB - Microwave effect on ET En ligne : https://drive.google.com/file/d/1Ld036J4ZIDxZ8VmpT4JEGTHhGEhKSqAP/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30904 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
20126	-	Périodique	Bibliothèque principale	Documentaires	Disponible

A novel and efficient collagen extraction method assisted by microwave irradiation / Jinwei Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 5 (05/2023)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVIII, N° 5 (05/2023) . - p. 199-207 Titre : A novel and efficient collagen extraction method assisted by microwave irradiation Type de document : texte imprimé Auteurs : Jinwei Zhang, Auteur ; Yulin Cheng, Auteur ; Jiacheng Wu, Auteur ; Wuyong Chen, Auteur Année de publication : 2023 Article en page(s) : p. 199-207 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Collagène -- Analyse Cuirs et peaux de bovins Extraction par micro-ondes Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A new and efficient microwave heating method was developed to extract intact Type I collagen from bovine limed splits. Orthogonal experiment was conducted to optimize the parameters of extraction, and the extraction yield was measured by ultraviolet spectra (UV). The hierarchical structures of the obtained collagen were determined by amino acid analysis, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), UV, Fourier transform infrared spectra (FT-IR), circular dichroism spectra (CD), fluorescence spectra (FL) and ultra-sensitive differential scanning calorimetry (US-DSC). The results indicated the optimal conditions for this microwave assisted extraction were 37°C for 7 h by using solid to liquid ratio of 1:45. The resultant yield of collagen was 14.35% under the optimal conditions, which is 1.5 times higher than that obtained by the control water bath-heating method. Amino acid analysis, UV and SDS-PAGE revealed that the primary structure of collagen extracted with microwave assistance was type I collagen. Although the extraction yield was promoted drastically with microwave assisting, the secondary structure of the collagen involving triple helix still maintained according to FT-IR, CD, FL and VP-DSC results. In brief, microwave irradiation could be a new routine for collagen extraction with advantages of fast and effective. Moreover, this study might offer a potential choice for utilizing hide or skin limed split wastes. Note de contenu : - EXPERIMENTAL : Materials - Sample preparation - Testing methods - Sodium dodecyle sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) - Fourier transform spectroscopy measurement (FT-IR) - Circular dichroism spectroscopy measurement (CD) - Fluorecence spectroscopy measurement (FL) - Ultra-sensitive differential scanning calorimetry (US-DSC) - RESULTS AND DISCUSSION : Optimization of microwave-assisting collagen extraction - Primary structure of collagen extracted by microwave assisted - Molecular weight of collagen - UV-Vis spectra of collagen - Secondary structure of collagen extracted by microwave assisted - CD spectra of collagen - The intrinsic fluorescence analysis of collagen - The synchronous fluorescence analysis of collagen - Denaturation temperature of collagen - Table 1 : Orthogonal test results of collagen extraction by microwave irradiation - Table 2 : Amino acid composition of different kinds of collagen - Table 3 : Thermal denaturation temperatures of different kinds of collagen DOI : https://doi.org/10.34314/jalca.v118i5.7361 En ligne : https://drive.google.com/file/d/1NerQcNZ1n2lQQya7MdR_RQWXnQk2kzjB/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39305 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
23954	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Penetration of the polyflavonoids and simple phenolics : a mechanistic investigation of vegetable tanning / Teng Bo in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 12 (12/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 12 (12/2017) . - p. 420-427 Titre : Penetration of the polyflavonoids and simple phenolics : a mechanistic investigation of vegetable tanning Type de document : texte imprimé Auteurs : Teng Bo, Auteur ; Jiacheng Wu, Auteur ; Wuyong Chen, Auteur Année de publication : 2017 Article en page(s) : p. 420-427 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse quantitative (chimie) Chromatographie en phase liquide à hautes performances Flavonoïdes Phénols Tannage végétal Tannage végétal -- Analyse Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Mechanisms of tanning are the fundamental base for predicting and developing new tanning agents and technologies. However, many mechanistic questions remain for us, such as: How does the penetration happen? How do the phenolic compounds work individually? In this study, penetration processes of the tannin extracts were investigated with the Bayberry extract (prodelphenidins), the Larch extract (procyanidins) and the Acacia Mangium extract (prodelphenidin-procyanidin complexes) used as tanning agents. During the process, the tanning liquids were regularly sampled and the simple phenolics and polyflavonoids were quantified respectively with a Prussian blue assay, a conductivity analysis, an acid-butanol assay as well as a HPLC analysis. The results showed that, during tannin, the concentration of polyflavonoids in the tanning liquid decreased continuously. In contrast, for the simple phenolics, the concentration decreased at first and later increased. Therefore, penetration processes of the tannin extracts can be described as: in the beginning, both simple phenolics and polyflavonoids started to penetrate; then the simple phenolics completed their penetration first and reversibly bound with collagens; in the meantime, the polyflavonoids were still penetrating and gradually replacing those simple ones from collagen matrix; at the end of the tanning processes, most of the simple phenolics were replaced by the polyflavonoids, meanwhile they were migrated back into the tanning liquids. The results will provide valuable information to help understanding the mechanism of vegetable tanning. Note de contenu : - EXPERIMENTAL : Sample preparation - Prussian blue assay - Conductivity test - Acid-butanol assay - HPLC Analysis - RESULTS AND DISCUSSION : The total phenolics in the tanning liquids - The simple phenolics in the tanning liquids - The polyflavonoids in the tanning liquids - The results of the HPLC analysis - The penetration process of the simple phenolics and the polyflavonoids En ligne : https://drive.google.com/file/d/12TJld_K4j2JVVhKQPVKHK9m1eTpim3mT/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29588 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
19426	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Special review paper : applications of microwave in leather field : further research for leather chemists and technologists / Jinwei Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 9 (09/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 9 (09/2017) . - p. 311-318 Titre : Special review paper : applications of microwave in leather field : further research for leather chemists and technologists Type de document : texte imprimé Auteurs : Jinwei Zhang, Auteur ; Jiacheng Wu, Auteur ; Wuyong Chen, Auteur Année de publication : 2017 Article en page(s) : p. 311-318 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Boues résiduaires Cuir, Travail du Cuirs et peaux Cuirs et peaux -- Séchage Extraction par micro-ondes Séchage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Summarized in this article is the substantial research and technology on applications of microwave in leather industry for effectively utilizing microwave in leather making. It includes effluent disposal, pretreatment for analysis, chemicals synthesis, leather drying and wet end processing. Also, the future studies based on microwave-assisted leather manufacturing are put forward. Microwave could shorten sludge drying time, indicating the use of microwave in leather effluents disposal could give a potential method for minimizing pollution. As an efficient pretreatment method, microwave assisting digestion and extraction could be used for the leather routine and hazard materials detection without any negative effect. In leather chemicals synthesis, faster reaction rate with better products could be obtained under microwave, suggesting it could be used in the processes further. Leather drying with microwave had advantages of fast drying such as uniform water distribution and higher area yield without hardening and shrinking. Furthermore, microwave in leather dyeing and tanning could improve the color fastness and hydrothermal stability of the leather. These studies demonstrated microwave was not only an excellent heat resource but also has a special non-thermal effect in leather making, which had some positive influences on the processes and leather properties. It is necessary to study the function and mechanism of microwave in leather making and the influence of microwave on leather properties and structure, especially non-thermal effect in the processes. This will give a potential choice for innovating leather technology, improving leather performance and promoting efficient. In summary, microwave introduced in leather industry will be an important further research field for leather chemists and technologists. Note de contenu : - Microwave-assisted leather effluents treatments - Microwave-assisted pretreatment for leather analysis and determination - Microwave-assisted leather chemical synthesis - Applications of microwave in leather drying - Applications of microwave in wet end - Expectation of applying microwave in leather making En ligne : https://drive.google.com/file/d/1wvGdZFv_uzqKk1bdIuh_9nDWuCpUDMQY/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29027 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
19110	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 5 / 5)