CotA laccase-ABTS/hydrogen peroxide system: An efficient approach to produce active and decolorized chitosan-genipin films

Idalina Gonçalves; Cláudia Nunes; Sónia Mendes; Lígia O Martins; Paula Ferreira; Manuel A Coimbra

doi:10.1016/j.carbpol.2017.08.029

CotA laccase-ABTS/hydrogen peroxide system: An efficient approach to produce active and decolorized chitosan-genipin films

Carbohydr Polym. 2017 Nov 1:175:628-635. doi: 10.1016/j.carbpol.2017.08.029. Epub 2017 Aug 10.

Authors

Idalina Gonçalves¹, Cláudia Nunes², Sónia Mendes³, Lígia O Martins³, Paula Ferreira⁴, Manuel A Coimbra⁵

Affiliations

¹ QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: idalina@ua.pt.
² QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.
³ Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
⁴ CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.
⁵ QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.

PMID: 28917910
DOI: 10.1016/j.carbpol.2017.08.029

Abstract

Chitosan-genipin films present a bluish-green color due to the conjugated double bonds formed when monomeric or dimeric genipin residues bridge chitosan. This phenomenon limits their use when colorless materials are required. In this work, a two-step oxidation strategy was developed aiming to remove color from chitosan-genipin films while preserving their functional properties. A combined system using the recombinant CotA laccase from Bacillus subtilis mediated by 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) followed by a H₂O₂ oxidation step was settled. ABTS boosted the laccase performance resulting in light brown chitosan-genipin films that were further decolorized upon immersion in a 5% H₂O₂ solution at pH 11.0 and 40°C for 30min. The applied methodology leads to films that sustain both acidic stability and antioxidant capacity of the pristine films. Overall, the combined CotA laccase-ABTS/hydrogen peroxide developed methodology efficiently produce active and decolorized chitosan-genipin films with potential for application as eco-friendly transparent material which may have application as food packaging.

Keywords: Active materials; Chitosan-genipin films; Decolorization; Hydrogen peroxide; Laccase; Mediator.