Zpracování kůže

Zpraocování kůže

• Several steps such
• Soaking
• Dehairing
• Bating
• Tanning

• Skin and hair are proteinaceous

• Conventional methods of leather processing
• Hazardous chemicals
• Sodium sulfide
• Create problems of pollution and effluent disposal

• Enzymes as alternatives to chemicals
• Proved successful in improving leather quality
• Reducing environmental pollution

• Proteases
• Selective hydrolysis of noncollagenous constituents of the skin
• Removal of nonfibrillar proteins such as
• Albumins
• Globulins

• Soaking
• Swell the hide
• Step was performed with alkali
• Microbial alkaline proteases
• Faster absorption of water
• Reduce the time required for soaking

• Nonionic - some extent anionic surfactants
• Compatible with the use of enzymes

• Dehairing and dewooling
• Conventional
• Extremely alkaline condition
• Followed by treatment with sulfide
• Solubilize the proteins of the hair root
• Alkaline proteases with hydrated lime and sodium chloride
• Significant reduction in the amount of wastewater generated

• Bating
• Kdysi use of animal feces as the source of proteases
• Unpleasant and unreliable
• Replaced by methods involving pancreatic trypsin
• Currently
• Trypsin in combination with other Bacillus and Aspergillus proteases for bating
• Selection of the enzyme depends on
• Specificity for matrix proteins
• Elastin and keratin
• Amount of enzyme needed
• Depends on the type of leather (soft or hard) to be produced

• Enzymes for dehairing and bating
• Prevents pollution problems
• Effective in saving energy

• Novo Nordisk three different proteases
• Aquaderm
• NUE
• Pyrase