Location:
2016 Annual Report
Objectives
1: Enable new commercial methods to reduce or eliminate manure contamination of hides prior to hide removal, and one or more process models will be
developed to estimate the expected costs for new technologies so enabled.
2: Enable new commercial methods for curing hides and skins and that reduce salt usage, and one or more models will be developed to estimate the expected costs for new technologies so enabled.
3: Enable new commercial methods to characterize hide quality in the raw
state, and one or more models will be developed to estimate the expected costs for new technologies so enabled.
4: Enable new commercial products from Keratin extracted from wool.
Approach
The cleaning of bovine hides to remove manure balls and other organic contaminants will be enhanced by incorporating a combination of enzymes, glycerol, and sanitizing agents into the traditional cleansing solution ingredients. The efficiency of manure cleansing will be assessed by monitoring the bacterial count before and after the hide washings. Low salt hide preservation will be developed by using the combination of dehydrating agent, biocide, glycerol, and sanitizing agents with a fraction of the amount of salt used in traditional hide preservation. For improved efficiency and extended bovine hide preservation, the addition of various polyethylene glycol (PEG) fractions will be evaluated with the treatments of glycerol, biocides, and sanitizing agents. Nondestructive evaluation technology will be developed for the characterization of hide quality by incorporating airborne ultrasonic (AU) technology. The through transmission mode will be applied so that more useful information can be extracted from the AU scan, particularly for hides, which are covered by hair. The amplitudes of the transmitted airborne signals at every point on the hide surface were measured, color-coded, and mapped into an image file for each hide or leather. The correlation between AU data and physical properties of hides will be examined and statistical software will be used to establish the regression equation that enables one to predict the quality of hides using AU testing. Keratin will be extracted from coarse, low grade, unmarketable wool, by environmentally benign and economical methods, functionally modified by chemo-enzymatic methods, and applied to domestic wool, yarn, or fabric, to improve its properties. Conditions for chemical and enzymatic modification of wool will be optimized at the bench scale first, then scaled up. Intact wool will be modified chemo-enzymatically to add functional groups or functionalized keratin, and evaluated for improved properties, such as softness, comfort, resistance to shrinkage or improved water repellency. Promising research begun under a previous project, that demonstrated the ability of transglutaminase to catalyze the attachment of O-phosphorylethanolamine, potentially a flame retardant, to keratin and other proteins will be adapted for the surface derivatization of wool fabric, with the aim of imparting flame resistance. Economic assessment will be performed for all objectives every 12 months to evaluate the progress toward targets with adjustment along the way as necessary. After the process model is developed with equipment sizing and unit operations, capital and operating costs are then estimated using cost analysis software.
Progress Report
For Objective 1, project scientists are developing a new method to reduce manure contamination on hides prior to removal of the hide from the carcass. The presence of manure on animal hides is a major concern to meat packers and butchers as a source of meat contamination. In addition, current methods for the removal of tightly bound manure balls from cattle hides often produce holes or other damage to the hide that decrease the value of the hide and the resulting leather products. As a first step, the strategy was developed to remove adobe type manure from pieces of hide by applying an oxidative chemical to the hide, followed by a physical operation such as drum tumbling to weaken the hair. Experimental results showed that the hair was significantly weakened and manure substantially removed in under 30 minutes. Mechanical test results of leather samples made after treatment were statistically the same as a control that was not exposed to the oxidative formula for manure removal. The low cost and eco-friendliness of our formula makes the oxidative manure removal method a viable option for cleaning hides and food safety. A preliminary analysis estimates that any added costs due to the use of our formula in a meat packing plant could be ameliorated by lower losses due to contaminated meat, and higher prices for the hides.
For Objective 2, project scientists developed an alternative short-term preservation method for bovine hides. The current industry formulation for brine curing (40% sodium chloride) was partially replaced with a formulation containing 20% sodium chloride with a low molecular weight polyethylene glycol (PEG-400) functioning as a polymeric dehydrant to reduce moisture and water activity during hide preservation. Preservation conditions were constant at 21 degrees C with relative humidity of 65%. Cured samples were stored for up to 30 days according to industry protocols. Cured hide samples were evaluated for resistance to molds, yeasts and other microbes according to the American Standard Testing Method International (ASTM) designated protocols. At the completion of the preservation study, the preserved hide samples were tanned into shoe upper leather following the USDA-ARS-Eastern Regional Research Center standard protocol and tested for quality following the ASTM protocols for analyzing tensile mechanical properties. Stereomicroscopic images of leather samples were captured to determine grain condition after leather processes. Chemicals used on green hides which resulted in the most optimal formulation treatment for effective preservation and quality leather were investigated for cost assessment and probable ability to accomplish preservation in pilot scale production.
For Objective 3, project scientists performed a systematic study and used a statistical experimental design to establish the relationship between key test parameters and responding Airborne Ultrasonic (AU) quantities, thereby establishing proper AU testing methods for raw hides. The investigation determined the relationship between AU quantities of hides and the mechanical properties of hides tanned into leather. It was discovered that two AU physical parameters of hides if used jointly showed good correlation with the mechanical properties of leather. The derived regression equations are useful for the estimation of leather mechanical properties based on the AU testing of hides, which would be applicable in a grading system. Current economic analysis has shown the proposed system to be comparable to the current manual grading system.
For Objective 4, project scientists extracted keratin from coarse, low grade, unmarketable wool, by environmentally benign and economical methods. For the development of methods for isolating high quality keratin fractions from U.S. coarse wool, published methods for solubilizing keratin from wool, hair and feathers were adapted and optimized for coarse wool, results were compared in terms of the extent of solubilization, molecular weight range of soluble proteins, and sharpness of molecular weight bands. Other factors considered for the economic evaluation were length of time for solubilization, required temperature, ease of performing the experiment, likely ability to upscale from the bench, and cost of materials.
Accomplishments
1. A novel method for removing adobe type manure on animal hides. The presence of manure on animal hides is a major concern to packers and butchers because it can be a source of meat contamination. Current methods for removing tightly bound hardened (adobe type) manure balls from cattle hides often leaves holes in the hide or damages the grain layer that decreases the value of the hide and the resulting leather products. ARS researchers in Wyndmoor, Pennsylvania investigated a new strategy for removing adobe type manure by shortening or weakening the hair by applying an oxidative chemical first followed by a physical operation such as drum tumbling. Results showed the manure was completely or substantially removed under 30 minutes. This novel method, makes removal of adobe type of manure more effective and speedy. It decreases or eliminates meat contamination, thereby improving the food safety for the consumer.
2. Biobased sponges derived from collagenous tannery waste. Due to fierce competition in global markets, the American leather and hide industries need to implement new technology for producing novel products using either raw hides or recycled tannery waste. ARS researchers in Wyndmoor, Pennsylvania addressed these challenges by developing novel products such as biobased, collagen sponges from hides and tannery waste. Collagen sponges have many unique properties that are desirable in medical applications. They are being widely used to stop bleeding in surgery and as scaffolds in tissue engineering. This research focused on preparations of collagen sponges from un-tanned hides, including limed hides and delimed-bated hides, which correspond with their actual tannery waste of limed splits and their trimmings. These research results are instrumental to help hides and leather industry to produce biobased sponges, which have many medical applications.
None.
Review Publications
Taylor, M.M., Bumanlag, L.P., Brown, E.M., Liu, C. 2016. Reaction of protein and carbohydrates with EDC for making unique biomaterials. Journal of American Leather Chemists Association. 111(4):155-164.
Brown, E.M., Taylor, M.M., Liu, C. 2016. Soluble collagen approach to a combination tannage mechanism. Journal of American Leather Chemists Association. 111(4):141-147.
Siddique, A., Latona, N.P., Taylor, M.M., Liu, C. 2016. Preparation of biobased sponges from un-tanned hides. Journal of American Leather Chemists Association. 111(5):192-199.
Taylor, M.M., Bumanlag, L.P., Brown, E.M., Liu, C. 2015. Biopolymers produced from gelatin and chitosan using polyphenols. Journal of American Leather Chemists Association. 110(12):392-400.
Ramos, M., Muir, Z.E., Uknalis, J., Trusello, J. 2015. Development of an alternative low salt bovine hide preservation using PEG and crude glycerol, part II: mechanical properties of leather products. Journal of American Leather Chemists Association. 110(5):125-129.
Ramos, M., Muir, Z.E., Trusello, J., Truong, N. 2015. Development of an alternative low salt bovine hide preservation using PEG and crude glycerol, part 1: evaluation of PEG molecular weight fractions. Journal of American Leather Chemists Association. 110(4):109-113.
Ashby, R.D., Solaiman, D., Liu, C., Strahan, G.D., Latona, N.P. 2015. Sophorolipid-derived unsaturated and epoxy fatty acid estolides as plasticizers for poly(3-hydroxybutyrate). Journal of the American Oil Chemists' Society. 93:347-358. doi: 10.1007/s11746-015-2772-7.
