Influence of the cattle breed on the properties of crusts / Sandra Stenzel in INTERNATIONAL LEATHER MAKER (ILM), N° 45 (01-02/2021)  

[article]  inINTERNATIONAL LEATHER MAKER (ILM) > N° 45 (01-02/2021) . - p. 38-41 Titre : Influence of the cattle breed on the properties of crusts Type de document : texte imprimé Auteurs : Sandra Stenzel, Auteur ; Michael Meyer, Auteur Année de publication : 2021 Article en page(s) : p. 38-41 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Allongement (mécanique) Bovins -- Races Croûte (cuir) On entend par "cuir en croûte" des cuirs ayant subi les opérations jusqu'au tannage, à l'exclusion de toute opération de corroyage ou de finissage, mais qui, par opposition aux wet-blue ont été séchés. Cuirs et peaux -- Propriétés mécaniques Epaisseur -- Mesure Mesures physiques Résistance à la déchirure Résistance à la traction Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The starting point of the investigations was the assumption of a lot of tanners that the leather quality in addition to other factors such as the tanning technology essentially depends on the cattle breed of a raw hide. This difference should be especially distinctive between Southern and Northern German cattle breeds. Tensile strength, maximum elongation and stitch tear resistance were selected as representative parameters for leather properties. The cattle breed was determined based on the raw hide using molecular biological methods. During the study, crusts were produced from all raw hides. Afterwards, the mechanical properties were investigated. It became apparent that the cattle breed does not have a significant influence on tensile strength, maximum elongations and stitch tear resistance of the crusts. Note de contenu : - Cattle breed and gender determination using molecular biological methods - Physical measurements - Fig. 1 : Cluster Arrangement for the 35 German cattle populations by program structure (1- Limousin, 2- Charolais, 3 and 4- Simentaler, 5, 6, 7, 8- Braunvieh, 9, 10, 11, 14, 15 Schwarzbunt/Rotbunt, 36 to 40- test data set). Every colour implies a cluster. Within a clust occur different colours, which indicates cross breeding - Fig. 2 : Thickness of the raw hides depending on the cattle breed determined using genetic markers (Southern German: Simentaler and Braunvieh, Northern German: Rotbunt (dual-use)/ Schwarzbunt and Rotbunt Holstein) - Fig. 3 : Tensile strength of the raw hides depending on the cattle breed determined using genetic markers - Fig. 4 : Tensile strength of the crusts depending on the cattle breed determined using genetic markers. The numbers in brackets stand for the number of samples (number of crusts). There are no significant differences between the individual cattle populations - Fig. 5 : Maximum elongation of the crusts depending on the cattle breed determined using genetic markers. The numbers in brackets stand for the number of samples (number of crusts). There are no significant differences between the individual cattle populations - Fig. 6 : Stitch tear resistance of the crusts depending on the cattle breed determined using genetic markers. The numbers in brackets stand for the number of samples (number of crusts). There are no significant differences between the individual cattle populations En ligne : https://drive.google.com/file/d/1abEO9_ylA0RVksVZgTam1hnDp_cIALy5/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35748 [article]

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A new marking system for leather based on encapsulated DNA / Sandra Stenzel in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 9 (09/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 9 (09/2015) . - p. 277-287 Titre : A new marking system for leather based on encapsulated DNA Type de document : texte imprimé Auteurs : Sandra Stenzel, Auteur ; Jörg Bohrisch, Auteur ; Michael Päch, Auteur ; Michael Meyer, Auteur Année de publication : 2015 Article en page(s) : p. 277-287 Note générale : Bibliogr. Langues : Américain (ame) Catégories : ADN Encapsulation Hydroxyapatite L'hydroxyapatite est une espèce minérale de la famille des phosphates, de formule Ca5(PO4)3(OH), usuellement écrite Ca10(PO4)6(OH)2 pour souligner le fait que la maille de la structure cristalline comprend deux molécules. L'hydroxyapatite est le membre hydroxylé du groupe apatite. L'ion OH- peut être remplacé par le fluor, le chlore ou le carbonate. L'hydroxyapatite cristallise dans le système hexagonal. La poudre d'hydroxyapatite pure est blanche. Celles que l'on trouve dans la nature peuvent cependant être de couleur marron, jaune ou verte. Marquage (technologie) Polystyrene-divinylbenzene Traçabilité Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The use of synthetic DNA as a marking system is a new traceability concept in the leather industry, especially for supplier and batch tracing. DNA is outstandingly suited for the usage as a marking system because of its code diversity, invisibility and doubtlessness. However, DNA labeling is a great challenge for products exposed to DNA damaging influences during their production, such as acidic pH, elevated temperatures in combination with high humidity or sunlight radiation. Leather is such a product. We attached single-strand DNA (ssDNA) to hydroxyapatite and enhanced the stability of these DNA particles by encapsulation in polystyrene-codivinylbenzene (PS-DVB) microcapsules. Furthermore, the ssDNA containing microcapsules were improved with functional groups on the surface of the capsule to irreversibly attach them to the collagen matrix of leather by chrome tanning. Laboratory scale tests using acidic conditions as well as elevated temperatures in the presence of high humidity showed that the stability of the leather marking system was enhanced. Marking trials were conducted in crust leathers, and the light fastness of these labeled crusts were tested. The results indicate that encapsulated DNA-hydroxyapatite-particles are more stable at sunlight radiation than non-encapsulated DNA. These marking trials showed that the system could be a suitable leather marking system in the leather industry to establish a powerful supplier and batch tracing. Note de contenu : - EXPERIMENTAL : Materials - Synthesis of functional monomers - Synthesis of PS-DVB microcapsules - Synthesis of PS-DVB microcapsules containing functional groups - Marking trials with non-encapsulated DNA as part of the base coat - Test of light fastness - DNA isolation from base-coat-marked leathers containing ssDNA - Laboratory scale test : 80°C - Marking trials with encapsulated ssDNA - Isolation of PS-DVB microcapsules from leather - DNA isolation from PS-DVB microcapsules - Quantitative real-time PCR(qPCR) and analysis of qPCR-data/statistics - Hide powder tanning - Fluorescence microscopy and scanning electron microscopy (SEM) - RESULTS AND DISCUSSION : Marking trials with non-encapsulated DNA (reference) - DNA stability of the optimized marking system at pH 2.0 and 80°C (laboratory scale tests) - Attachment of PS-DVB microcapsules to the collagen-matrix of leather - Marking trials with the optimized marking system En ligne : https://drive.google.com/file/d/1Ozm4zylpjZbd88jgOLdE3QM9hrmkpB77/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24595 [article]

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