Processing poultry feathers into keratin hydrolysate through alkaline-enzymatic hydrolysis

Waste Manag Res. 2011 Mar;29(3):260-7. doi: 10.1177/0734242X10370378. Epub 2010 May 18.

Abstract

Poultry feathers make up for as much as 8.5% of chicken weight and represent a considerable amount of almost pure keratin waste which is not being adequately utilized at the present time. The present study dealt with the processing of poultry feathers through a two-stage alkaline-enzymatic hydrolysis. In the first stage, feathers were mixed with a 0.1 or 0.3% KOH water solution in a 1 : 50 ratio and were incubated at 70°C for 24 h. After adjusting pH to 9, the effects examined in the second processing stage on the amount of degraded feathers were those of proteolytic enzyme additions (1-5%), time (4-8 h) and temperature (50-70°C). Processing feathers in 0.3% KOH and hydrolysing for 8 h in the second stage at 70°C with a 5% dose of enzyme (relative to dry feathers weight) produced approx. 91% degradation. Keratin hydrolysate is distinct for its high nitrogen content and reasonable inorganic solids level. Two-stage technology of alkaline-enzymatic hydrolysing of poultry feathers in an environment of 0.3% KOH achieves high efficiency under quite mild reaction conditions (temperature not exceeding 70°C with pH in a mildly alkaline region), and is feasible from an economic viewpoint. Keratin hydrolysate can find particular application in packaging technology (films, foils and encapsulates).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Feathers / chemistry*
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Industrial Waste / analysis*
  • Industrial Waste / statistics & numerical data
  • Keratins / chemistry*
  • Peptide Hydrolases / chemistry*
  • Poultry*
  • Refuse Disposal / methods*
  • Temperature

Substances

  • Industrial Waste
  • Keratins
  • Peptide Hydrolases