EVALUATION OF DEGREASING PROCESS WITH PLANT DERIVED BIOSURFACTANT FOR LEATHER MAKING: AN ECOLOGICAL APPROACH

This paper describes the application of extracts of Quillaja bark saponin, a plant derived biosurfactant, as alternative low cost natural surfactants for the degreasing of sheep skins. Pickled sheep skins were treated using three commercial products of Quillaja saponaria saponins with different degrees of sapogenin content: Q1 (Sigma, 26%), Q2 (AppliChem, 12%) and Q3 (Carl Roth, 10%). The effect of saponin based biodegreasing was investigated in terms of chemical oxygen demand (COD) of residual floats, quantification of colour and scanning electron microscopic visualization of the biodegreased leathers. Degreasing efficiency levels up to 82%, 79% and 78% was attained with 3.75% sapogenin content of Q1, Q2 and Q3 respectively. COD values for degreasing effluents were reduced by 70%, with 3.125% offer of Q1 saponin. The results indicate that the properties of biodegreased leathers are comparable with those of conventionally processed leathers with respect to dye levelness and physical texture. This novel saponin based degreasing process can be a viable and promising ecological degreasing option for leather industry.