Treatment of Hides with Tara-modified Protein Products

Abstract

In prior research, we demonstrated that gelatin could be modified with quebracho to produce products whose physicochemical properties would enable them to be used effectively as fillers in leather processing, and that leather resulting from this treatment had improved subjective properties with little effect on mechanical properties. In an extension of the study, the tannin, tara was examined for its potential in gelatin modification. The advantage for using tara is that it gives an almost colorless product, which would be desirable in production of light colored leather, as well as imparting light fastness to the leather. The conditions for optimal tara modification of gelatin were determined and the products characterized. In this present study, these tara-modified gelatins were evaluated as fillers in the treatment of wet blue and wet white. In addition, the rate of uptake of the product was also examined using an analysis developed at ERRC for the measurement of polyphenols in foods. It was found that the treated leathers, when evaluated for their subjective properties (handle, fullness, break and color), demonstrated improved properties. There were no significant differences in treated and control samples of wet blue and wet white, with respect to the mechanical properties (tensile strength, elongation, Young’s Modulus, toughness index and tear strength). SEM examination of fiber structure showed differences in treated and untreated samples. Thus, another sustainable, economical resource, the polyphenolic tara, in conjunction with gelatin, has further shown its potential for use in leather production.