| 摘要 |
The soaked pelts and hides are treated in a bath having pH 9-11 with proteolytic enzymes having optimum activity at pH 2-7.5. - Pref. (a) acid proteases having optimum activity at pH 2-7 are prefd., esp. acid fungus proteases partic. of Rhizopus sp., Aspergillus spp. and Penicillium sp.. (b) The acid proteases have proteolytic activity 500-200 mUHb-units/g. (c) The amt. of proteolytic enzymes used is 2-10 mUHb w.r.t. g/salt or dry wt. of pelts and hides, eg. 4-6 mUHb/g dry wt. for unhairing kid pelts and 2-3 mUHb/g for large cattle; 4-6 mH/Hb/g for de-bristling pigskin and 6-8 mUHb/g salt wt. for removing wool off sheepskins. (d) The bath makes up 100-300 wt.% w.r.t. the soaked wt. of the pelts and hides. (e) The proteolytic enzyme treatment takes 12-36 hrs. e.g. at 25-27 deg.C.. (f) Unhairing is facilitated by stripping the flesh after soaking.
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