Location: Biobased and Other Animal Co-Products
Title: Development of an alternative low salt bovine hide preservation using PEG and crude glycerol, part 1: curing efficiency in terms of its dehydration and rehydration rate and chloride content Authors
Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 30, 2013
Publication Date: N/A
Interpretive Summary: The raw hides consist mainly of protein and water, which makes them vulnerable to microbial attack and decomposition once the hides are taken off the slaughtered animals for their meats. The high moisture content and other nutrients of the raw hide attract and support the growth of microorganisms which can then degrade the protein making the hides unsuitable for the production of good quality leather. The removal or reduction of the hide moisture content is the most important factor to consider when developing an effective hide preservation process. Unfortunately, high salt concentration of about half the weight of the raw hide is required in brining, commonly used preservation process. During tanning, the excess salt has to be removed in order not to interfere with the tanning chemicals and has been the source of a tremendous pollution problem. It is imperative that the hides and leather industry develop alternative environmentally friendly hide preservation that requires lower concentration of salt in order to diminish the environmental impact that the traditional standard salt preservation can introduce. ARS scientists at Wyndmoor, PA have developed an improved preservation process by incorporating a water absorbing agent such as the polymer of polyethylene glycol (PEG). Results showed that only a fraction of the usual salt concentration is necessary to generate environmentally friendly and efficiently preserved hides.
Technical Abstract: Brine curing is the widely used temporary preservation of cattle hides where the common salt, sodium chloride is utilized. Due to economics and efficiency, it has become the traditional and commonly used hide preservation method by meat packers, hide processors, and tanners worldwide. But it is known to introduce serious effluent pollution problems to the environment. The main objective of the current study is to develop an alternative brining process that requires lesser amount of salt to effectively preserve bovine hides by incorporating dehydrating agents. The hardening effect due to the dehydration caused by the polymer of polyethylene glycol (PEG) can be compensated by adding crude glycerol and sodium carbonate in low salt preservation. The low molecular weight PEGs are more promising than the high molecular weight polymers. The preservation was found to be effective because no sign of putrefaction was observed in alternatively cured hides and are comparable to the traditionally cured control hides. By incorporating PEG, only a fraction of the commonly used salt concentration is necessary to generate an efficiently preserved hide that is also environmentally friendly.