Characterisation of keratin biomass from butchery and wool industry wastes

Abstract: The chemical and structural characteristics of wool and horn-hoof were compared with the aim of better addressing possible exploitation of protein biomasses available as waste from textile industry and butchery. Amino acid analysis showed that wool has a higher amount of cystine and a lower amount of the amino acids that favour alpha-helix formation than horn-hoof. The difference in the alpha-helix content is confirmed by FTIR spectroscopy. Electrophoresis separation patterns showed two characteristic protein fractions related to low-sulphur proteins (between 60,000 and 45,000 Da) in wool, while different low-sulphur proteins are present in horn-hoof These data are partially confirmed by DSC analyses that showed different endothermic peaks at temperatures higher than 200 degrees C in the horn-hoof thermograms, probably due to denaturation of alpha-keratins at different molecular weights. Moreover. wool keratin was more hygroscopic and showed a higher extractability with reducing agents than horn-hoof On the basis of these results. waste wool is a more Suitable source than horn-hoof for uses involving protein extraction, but application can be envisaged also in surfactant foams for fire extinguishers and slow-release nitrogen fertilizer.