Two antimicrobial gels, formulated with natural biopolymers (collagen and chitosan), limonene, and an imidazole derivative, were subjected to cytotoxicity tests. In these two compositions, the limonene content was 0.4% and 0.67%. The cytotoxicity tests were performed in vitro, using MTT methodology, and a standardized human normal cells line, HUVEC type. These cells were exposed to different levels of gel concentrations in the culture media. The final concentration of each gel type in culture media was situated between (0-0.125) μL/mL. The cell viability was determined after 24, 48 and 72h of exposure. The analyses showed that after 24h of exposure, the viability of the cells is greater than 91%, after 48h the viability is greater than 80%; after 72 h of exposure, the viability of the cells is greater than 74%. These values reveal that both selected gels exhibit no cytotoxicity for the normal cell line.
Chrome tanning is an essential process to convert raw animal skin into leather, in which collagen, as the main structure of leather, is stabilized against degradation through cross-linking using chromium, consisting of two steps: penetration and basicity. However, the uptake of chrome in leather still needs to be improved. The purpose of this study was to find the best heating time in the chrome tanning process by thermal analysis. Pickled sheepskin was used as raw material for the chromium tanning process. The samples were varied into four categories: heated at the penetration stage of the tanning process (Initial Heating), heated at the basification stage of the tanning process (Final Heating), and heated both at the penetration and basification stage (Continuous Heating). In this study, the thermal stability of wet blue leather was evaluated by shrinkage temperature behavior (Ts), thermogravimetry analysis (TGA/DTG), and differential scanning calorimetry (DSC). The tanning efficiency was measured by Cr2O3 content. The results demonstrated that wet blue samples heated continuously shows better thermal characteristics. In conclusion, the results can be used for finding the best possible technique for the leather tanning process using chrome salts to gain thermal stability.
Adopting pollution prevention strategies (PPS) can ensure environmental sustainability (ES) in the leather industry and can help the industry achieve several sustainable development goals (SDGs). In order to ensure the ES of the leather industry, there is a need for research to identify a comprehensive list of PPS. This research aims at identifying the most effective PPS for the leather industry, which are categorized into 4R (reduce, reuse, recycle, and recover) dimensions. This is a case study where four leather processing companies from Bangladesh were purposively selected. Through an extensive literature review and experts’ opinions, 21 PPS are identified for the leather industry’s ES. Also, this study shows several benefits of PPS through which various SDGs can be achieved in the leather industry. This study will certainly guide the leather industry managers to ensure the ES of the leather industry and, consequently, assist in achieving several SDGs.
Microorganism activity during soaking beamhouse process of leather production is highly dangerous and should be kept under control. Some chemical components are used for this purpose to protect the hides/skins against microbial activities. Because of the banned and restricted substances due to the environmental and health risks in the recent times, natural active ingredients are considered for industrial production as sustainability. Moreover, supercritical fluid extraction as an environmentally friendly technology is applied to isolate biologically active extracts and supercritical extracted natural compounds are reported as potential antioxidant and antibacterial agent for several applications. In this study, supercritical fluid extracted chestnut tannin was used in soaking process of leather production and was determined as potential natural biocide with very good effect against microorganism activity in the process floats.
The aim of this paper is to study the applications of enzymes, as ecological alternatives in the leather industry. The research proposes to create ecologic leathers/furs with additional functions (non-toxic, with high-quality of soft, well-degreased surfaces) through the use of original enzyme-based biotechnologies, as new additives for leather/fur processing intended for everyday use. Another application of the enzymes studied in this paper is the development of a novel technology based on enzymes and membrane technique, for purifying wastewaters from the leather industry. We selected and analytically characterized lipases, proteases, and also new enzymes: lysozyme, tryptophan deaminase for use in leather industry. The goal was to obtain leathers/furs for everyday use, with high-performance characteristics, by processing them with enzymes – as new additives that have not been used so far in the leather industry as an alternative to the use of potentially polluting chemical materials. Complex and original technologies of ecological bioprocessing of leather/furs were used. The innovation consists in developing new biotechnologies for leather/fur with enzymatic additives in order to achieve ecologic leathers or fur articles. These biotechnologies provided advanced performances for surface quality: intense and bright colors, soft, well-degreased, and resistant to abrasion and water.
