ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Enhanced keratin extraction from wool waste using a deep eutectic solvent

Oseweuba Valentine Okoro, Hafez Jafari, Parinaz Hobbi, Lei Nie, Houman Alimoradi, and Amin Shavandi

Université Libre de Bruxelles (ULB), École Polytechnique de Bruxelles - BioMatter Unit, Brussels, Belgium

E-mail: nielei@xynu.edu.cn

Received: 4 October 2021  Accepted: 17 December 2021

Abstract:

Abstract

In this study, the solubilization of waste coarse wool as a precursory step for the large-scale valorization of keratin was investigated using a green deep eutectic solvent (DES) based on L-cysteine and lactic acid. The investigation was undertaken via the response surface methodology and based on the Box–Behnken design for four process variables of temperature (70–110 °C), dissolution time (2–10 h), the mass of L-cysteine (0.5–2.5 g) in 20 mL of lactic acid, and wool load in the DES (0.2–0.6 g). Temperature was the most significant process variable influencing keratin yield from the waste coarse wool. The optimum keratin yield (93.77 wt.%) was obtained at the temperature of 105 °C, 8 h dissolution time, with 1.6 g L-cysteine in 20 mL of lactic acid using 0.5 g of wool. This study suggests L-cysteine and lactic acid as a green solvent with the potential to scale up keratin recovery from waste wool without significant destruction in the structure of the recovered keratin.

Graphical abstract

Keywords: Deep eutectic solvent; Green keratin extraction; Optimization; Surface response methods; Waste valorization

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-02029-4

Chemical Papers 76 (5) 2637–2648 (2022)