Bacterial and fungal damage in leather / Joseph Ondari Nyakundi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 8 (08/2023)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVIII, N° 8 (08/2023) . - p. 327-339 Titre : Bacterial and fungal damage in leather Type de document : texte imprimé Auteurs : Joseph Ondari Nyakundi, Auteur Année de publication : 2023 Article en page(s) : p. 327-339 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Biodégradation Cuirs et peaux -- Analyse Cuirs et peaux -- Détérioration Détérioration bactérienne Détérioration fongique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Microbial degradation leads to significant loss of quality and economic value by the tanner. This damage cannot be reversed as it involves the degradation of the collagen and elastin fibers, which are important proteins in the leather-making process. It is, therefore, important to carefully monitor the after-slaughter, curing, beamhouse and posttanning processes to prevent this type of damage. This is only possible if you can identify the signs and/or defects caused by bacteria and fungi as early as possible and put in place corrective measures to halt any further or future damage. This study evaluated various techniques for identifying bacterial and fungal damage in leather, including visual inspection, smell, feel, microscopy, and culturing techniques. Samples of cured hides and leather obtained from different sources in the USA were subjected to these techniques to determine the presence of these microbes or to identify their damage. The results highlight various defects and indicators that point to various microbial causes. A combination of visual inspection, microscopy, and culturing techniques can provide hides and skins sellers, packers, and tanners with reliable and accurate identification techniques for identifying early signs of damage. While microscopy was sufficient to observe fungal growth and bacterial damage, culturing was more reliable for identifying the bacterial causative agents. This study highlights the importance of implementing routine inspections and monitoring to prevent continued microbial damage to hides to ensure the quality of the leather. Note de contenu : - INTRODUCTION : Biodeterioration in leather - Impact of biodeterioration on the quality of leather - MATERIALS AND METHODS : Materials - Methods : Custuring techniques - Visual examination - Microscopic examination - RESULTS AND DISCUSSION : Culturing techniques - Visual inspection and microscopy - Table 1 : Biological activity reaction test results after 8 days - Table 2 : Paddle test results after the 48 Hr. - Incubation period - Table 3 : Total aerobic bacteria testing result after 48 hour - Table 4 : Yeast and mold testing results after 5 days - Appendix 1 : Paddle test DOI : https://doi.org/10.34314/jalca.v118i8.8090 En ligne : https://drive.google.com/file/d/1G_Sd25joYXHJN7SPlNKK1QUnlgTwUnBu/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39672 [article]

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Recovery of industrially useful hair and fat from enzymatic unhairing of goatskins during leather processing / Joseph Ondari Nyakundi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 6 (06/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 6 (06/2022) . - p. 241-250 Titre : Recovery of industrially useful hair and fat from enzymatic unhairing of goatskins during leather processing Type de document : texte imprimé Auteurs : Joseph Ondari Nyakundi, Auteur ; Jackson Nyarongi Ombui, Auteur ; Wycliffe Chisutia Wanyonyi, Auteur ; Francis Jakim Mulaa, Auteur Année de publication : 2022 Article en page(s) : p. 241-250 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation Cuirs et peaux de chèvres Epilage enzymatique Essais (technologie) Evaluation Huiles et graisses -- Recyclage Huiles et graisses animales Poils -- Recyclage Qualité -- Contrôle Récupération (Déchets, etc.) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Leather processing not only serves social needs by putting into use the meat industry’s by-products (hides and skins) but also makes a significant contribution to global economic growth through trade and job creation. In the wake of globalization, however, leather manufacturers are facing new challenges in meeting environmental imperatives and improving the utilization of wastes generated during leather processing. This study describes the recovery of hair and fat from fleshings obtained after enzymatic unhairing of goatskins using a protease from an isolate of Bacillus cereus Strain 1-p. The recovered hair and fats were further characterized to facilitate recommendations for different industrial applications. The following hair properties were visually examined and evaluated by hand ; straight length, density and uniformity, hair strength and overall quality. The fats were analyzed by characterizing the fatty acid composition using the Gas Chromatography-Mass Spectrometry (GC-MS analysis). The recovered hair was intact and rated to be of average to good quality. The fat characterization indicated that methyl 9Z-octadecenoate (9Z-heptadecenoic acid; oleic acid) was the most abundant fatty acid with an abundance of 31.65%. The sulfide-free fats and intact hair, therefore, were recommended for use in various industrial applications such as manufacturing of poultry feedstuff, organic fertilizers, biodiesel and biofuels, fatliquoring agents, soaps and cosmetics after further purification where necessary. The hair and fats recovered from this study are particularly advantageous over those recovered from sulfide unhairing systems as they are free from any sulfides or lime contamination thus easier to purify and use. The study concluded that the use of the enzyme extract from Bacillus cereus Strain 1-p to unhair goatskins facilitated the recovery of valuable hair and fats that can be used for other industrial applications. Note de contenu : - MATERIALS AND METHODS : Materials - Methods (Enzyme preparation - Unhairing of goatskins) - Characterization of the recovered products - RESULTS AND DISCUSSION : Recovered hair analysis - Recovered fat analysis - Table 1 : Assesment of recovered hair quality - Table 2 : Fatty acids test results DOI : https://doi.org/10.34314/jalca.v117i6.4965 En ligne : https://drive.google.com/file/d/13xpAHCyMlTJBIwqMWXKZCUw9d_FUgOJp/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37799 [article]

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