Abstract

Considering the importance that is attached to the characterisation of proteolytic enzymatic preparations employed in leather making, especially in the development of enzyme unhairing, our studies are aimed to develop a protocol of analysis that allows us to determine the behaviour of the enzymes on diverse protein skin substrates. In the protocol presented here it is important to highlight the incorporation of the so-called ‘epidermis substrate’, comprising the epidermis layer, hair and the root sheaths, as well as the procedure to assess enzymatic action on the proteoglycans.

On two of the substrates, “epidermis” and Hide Powder Azure, studies on activation/inhibition of the enzyme activity using components usually added in the soaking and unhairing processes was also carried out.

The protocol was applied to two commercial enzymatic preparations commonly used in leather processing, and to an extract of vegetable proteases that CITEC, jointly with LIPROVE, is applying in its investigation on enzyme unhairing.

The protocol developed is a useful tool to assist us in the design of ideal enzyme unhairing: that in which the enzymatic activity is orientated towards the components of the epidermis system, when their action on fibrous proteins – particularly collagen – is minimised or avoided and when the leathers developed have the desired properties.