A novel system of removing decorin, a minor proteoglycan of bovine hides, to improve the quality of leather

Authors: Ramos, Mila; Liu, Cheng Kung

Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2010
Publication Date: 7/1/2010
Citation: Ramos, M., Liu, C. 2010. A novel system of removing decorin, a minor proteoglycan of bovine hides, to improve the quality of leather. Journal of American Leather Chemists Association. 105(7):222-228.

Interpretive Summary: The goal of this research was to develop ways to improve the quality of leather by further removal of a glue-like minority component--decorin, which is a proteoglycan (part protein and part carbohydrate). Even though it has been postulated that further removal of decorin could improve the softness of the resultant leather, it is only now that this is actually illustrated in this report. Additional removal of decorin was observed when specific proteolytic enzymes were added during the pretanning stage of tanning hides into leather. More pronounced improvement in leather quality was observed in oxidatively dehaired hides than those dehaired traditionally with sodium sulfide. Our results showed that in general, the lower the residual decorin content the better the quality of leather. As the decorin content decreased, the leather product became softer, more stretchable, and as tough as the control leather tanned without co-treatment with proteolytic enzymes. Employing the alternative environmentally friendly oxidative dehairing process may solve the problem of sulfide toxicity to the environment while at the same time improving the quality of leather if co-treated with proteolytic enzymes.

Technical Abstract: The goal of this research was to explore ways to improve the quality of leather by the removal of more decorin. Further removal of decorin was achieved with the addition of proteolytic enzymes during pretanning. The majority of decorin removal took place during the dehairing of hides, either traditionally with sodium sulfide or by an alternative oxidative dehairing procedure. Additional removal of decorin was observed in hides dehaired by either method by subjecting the hides to pretanning treatments in the presence of alkaline protease during the relime stage and pepsin in the pickling stage. However, further improvement in the quality of the resultant leather was observed in oxidatively dehaired hides, rather than those dehaired traditionally with sodium sulfide. Our results showed that in general, the lower the decorin content, the better the quality of leather. As the decorin content decreased, the leather became softer, more elastic, and as tough as the leather not treated with proteolytic enzymes. Employing the alternative environmentally friendly oxidative dehairing process in conjunction with the protease treatment described in this report may solve the problem of sulfide toxicity to the environment while also improving the quality of leather.