Primary quality assessment of keratin extracted from chicken feather waste as feed component
Keywords:Keratin, waste valorization, alkaline hydrolysis, feed supplement
The present study suggests an effective method to solve the feather waste problem from poultry industries. Annually, the amount of feather waste is tendentiously increasing. This gives rise to an enormous amount of chicken feather waste, which is difficult to eliminate because of its resistance to the degradation. The main composition of the chicken feathers is a structural protein called keratin. This protein can compose up to 90% of feathers. The disulfide bridge (S−S) between cysteine in keratin causes it to possess high stability and water-insolubility. In case of improper feather discard, adverse impacts to the environment could possibly occur; e.g. pathogenic source creation and unwanted smells. Thus, the present work aims to seek for an appropriate method to utilize chicken feather waste. Chicken feathers were cleaned and degreased before being subjected to alkaline hydrolysis using a 2.5% NaOH solution (pH 13) at 70°C for 75 min. The extraction yield was 94.22 ± 0.72 %. The remaining debris was separated by centrifugation and was accounted for 5.78 ± 0.72 %. Consequently, the supernatant was collected and keratin was then precipitated by solid ammonium sulfate using 50% saturation and eventually harvested. Finally, the crude keratin was dried overnight at 80°C.
The yields of crude keratin extract was 34.82 ± 1.84 %. Three samples of crude keratin extract were obtained and the quality of the crude samples was further analyzed by nitrogen content and in vitro digestibility to assess the possible use in feed component. By this method, feature waste was not only eliminated, but also valorized to obtain crude keratin, which can be further utilized in broad applications, especially in animal feed industry.
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