Gallic acid, gallic acid esters with various chain lengths, tara and tara hydrolysates are compared with one commercially successful synthetic phenolic antioxidant in various protocols for antioxidant testing, and regarding their capability to reduce the proneness to Cr(VI) formation in leather. The results are discussed in light of the Polar Paradox Theory and the possible interaction of the antioxidants with components in the leather matrix. The aim of these investigations is an optimum prevention of Cr(VI) formation in leather.
Adobe-type (hardened) manure attached to bovine hair is a major source of meat contamination, hide quality deterioration, and devalued leather products. Therefore, it is important to develop cleaning solutions that can rapidly remove adobe-type manure to improve the quality of hides delivered to tanners for leather processing. Oxidative chemicals such as sodium percarbonate (SPC) have been used as an environmentally friendly alternative to dehair bovine hides in 1-4 hours. In this study, we do not aim to dehair the hide with SPC, but to weaken and shorten the hair enough to remove the adobe-type manure from the hide in under 30 minutes. Our formula substantially removed adobe-type manure in less than 30 minutes using a combination of SPC and sodium hydroxide (NaOH) as a soaking solution in a tumbling drum. Fourier Transform Infrared (FTIR) spectroscopy showed the oxidation of cystine disulfide bridges in keratin, the structural protein of hair, indicating that our formula weakened the hair after treatment. A decrease in hair diameter, or hair shortening, was also observed with Scanning Electron Microscopy (SEM) analysis after treatment of the hides with our formula. Our environmentally friendly formula for oxidatively removing adobe-type manure is a viable option to enhance both meat and hide quality.
High quality, clean, and well-preserved hides are paramount for competitiveness in both domestic and export markets. Currently, hides are visually inspected and ranked for quality and sale price, which is not reliable when hair is present on the hides. Advanced technologies are needed to nondestructively and accurately characterize the quality of hides and enable one to predict the mechanical properties of leather. Research was carried out to develop airborne ultrasonic (AU) methods to nondestructively characterize the quality of hides that are useful for predicting the mechanical properties of leather. The developed nondestructive method is based on measuring the AU waves transmitted through the hide samples. We performed a systematic study and used a statistical experimental design to establish the relationship between key test parameters and responding AU quantities, thereby establishing proper AU testing methods for hides. Moreover, observations showed AU parameters derived from the distributions of Time of Flight (TOFd) and the amplitude of transmitted waves (AMPd) have a strong correlation with the mechanical properties of leather. This study demonstrated that the tensile strength, stiffness, elongation, and toughness of leather could be nondestructively predicted by the physical quantities obtained from AU testing of hides.
The purpose of this work is to compare the environmental impact of two systems for processing bovine leather: (i) a new continuous system that consists in dehydration and tanning and post-tanning by immersion versus (ii) the traditional system using drums.
In order to better assess the environmental impact of this new tanning system, the life cycle assessment methodology has been chosen to perform calculations on various impact categories, including the global warming potential (CO2 equivalent emissions), and the energy consumption for both the traditional and the new tanning processes.
When assessing the environmental impact of the new system, it is clear that a reduction in the use of acetone during the process will positively affect the environmental outcomes. In this regard, results show reductions on the impacts in eight out of the eleven impact categories analyzed as well as reductions on energy consumption. However, the acetone loss considered (5%) led to higher impacts compared to the traditional system in three specific impact categories, which can be improved by reducing the acetone emission to 2.5%.