Processing poultry feathers into keratin hydrolysate through alkaline-enzymatic hydrolysis.
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).
Mokrejs
Pavel
P
Faculty of Technology, Department of Polymeric Engineering, Tomas Bata University, Zlin, Czech Republic. mokrejs@ft.utb.cz
Svoboda
Petr
P
Hrncirik
Josef
J
Janacova
Dagmar
D
Vasek
Vladimir
V
D000818:Animals; D005241:Feathers / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste / Q000032:analysis* / Q000706:statistics & numerical data; D007633:Keratins / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000737:chemistry*; D011200:Poultry; D012037:Refuse Disposal / Q000379:methods*; D013696:Temperature
D007220:Industrial Waste; D007633:Keratins; D010447:Peptide Hydrolases