Utilization of agricultural by-products to partially replace gelatin in preparation of products for leather

Authors: Taylor, Maryann; Bumanlag, Lorelie; Lee, Joseph - Joe; Latona, Nicholas - Nick; Brown, Eleanor - Ellie; Liu, Cheng Kung

Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2014
Publication Date: 1/5/2015
Publication URL: http://handle.nal.usda.gov/10113/60216
Citation: Taylor, M.M., Bumanlag, L.P., Lee, J., Latona, N.P., Brown, E.M., Liu, C. 2015. Utilization of agricultural by-products to partially replace gelatin in preparation of products for leather. Journal of American Leather Chemists Association. 110(1):13-18.

Interpretive Summary: We recently showed that products which could improve the quality of leather could be made by modifying waste proteins, e.g. gelatin and whey protein concentrate (WPC), using the renewable vegetable tannin tara. Currently, the cost of gelatin is increasing, because, for a variety of reasons, it is in limited supply. There is a pressing need to find a substitute that could be combined with the gelatin, thus, reducing the amount of gelatin required, with the objective that the new products would keep the desired characteristics of gelatin products. We decided to try to produce a biopolymer product, using gelatin and WPC modified with tara, and optimal conditions for modification were determined. In this ongoing study, this product was applied to hides to determine if we could improve the quality of the resulting leather. It was determined that the subjective properties of the leather (for example, pliability and fullness) were significantly improved over control samples that were not treated. The mechanical properties of the treated samples (for example, the ability to tear the leather) were not significantly different than the control samples. At the same time, a method was developed to determine the rate of uptake of the product. Hence gelatin, a byproduct from the leather industry and WPC a byproduct of the dairy industry, modified with tara, a commonly employed and renewable tanning agent, could be utilized to improve leather products and at the same time, this biopolymer product would reduce the amount of gelatin needed to make products that would be comparable to using gelatin alone.

Technical Abstract: When polyphenolic-modified gelatin-products were used as fillers, improvements were seen in the subjective properties of the leather. When the treated samples were compared to control samples, there were no significant changes in mechanical properties. At the present time, gelatin is in short supply, costs are increasing, and there is an urgent need to find a substitute that could be combined with the gelatin, thereby, partially replacing and reducing the amount of gelatin required, with the goal that the new products would retain the desired characteristics of gelatin products. We have evaluated the potential of producing biopolymers from the reaction of polyphenols with gelatin in combination with other proteins (e.g. whey) or with carbohydrates (e.g. chitosan and pectin). Several researchers have recently demonstrated the feasibility of these reactions. These combinations would take advantage of the distinctive properties of both species, and at the same time, create products with improved functional properties. Recently, the preparation of polyphenolic-modified gelatin/whey biopolymer products was investigated, and the results of product characterization using physicochemical analyses indicated optimal products that could be used as fillers. In this continuing study, these products were applied to wet white, that was then finished, and subjective and mechanical properties were evaluated. At the same time, a method was developed to determine the rate of uptake of the product. Results of the studies will be presented. These findings could further add to the knowledge of using renewable resources in production of unique products that may have leather processing application.