Active biodegradable packaging films modified with grape seeds lignin

Pavel Vostrejs; Dana Adamcová; Magdalena Daria Vaverková; Vojtech Enev; Michal Kalina; Michal Machovsky; Markéta Šourková; Ivana Marova; Adriana Kovalcik

doi:10.1039/d0ra04074f

Active biodegradable packaging films modified with grape seeds lignin

RSC Adv. 2020 Aug 7;10(49):29202-29213. doi: 10.1039/d0ra04074f. eCollection 2020 Aug 5.

Authors

Pavel Vostrejs¹, Dana Adamcová², Magdalena Daria Vaverková^{2

3}, Vojtech Enev⁴, Michal Kalina⁴, Michal Machovsky⁵, Markéta Šourková², Ivana Marova¹, Adriana Kovalcik¹

Affiliations

¹ Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology Purkynova 118 612 00 Brno Czech Republic kovalcik@fch.vut.cz.
² Department of Applied and Landscape Ecology, Faculty of AgriSciences, Mendel University in Brno Zemědělská 1 613 00 Brno Czech Republic.
³ Institute of Civil Engineering, Warsaw University of Life Sciences - SGGW Nowoursynowska 159m 02 776 Warsaw Poland.
⁴ Department of Physical and Applied Chemistry, Faculty of Chemistry, Brno University of Technology Purkynova 118 612 00 Brno Czech Republic.
⁵ Centre of Polymer Systems, Tomas Bata University in Zlín Třída Tomáše Bati 5678 760 01 Zlin Czech Republic.

Abstract

Biodegradable packaging materials represent one possible solution for how to reduce the negative environmental impact of plastics. The main idea of this work was to investigate the possibility of utilizing grape seed lignin for the modification of polyhydroxyalkanoates with the use of its antioxidant capacity in packaging films. For this purpose, polymeric films based on the blend of high crystalline poly(3-hydroxybutyrate) (PHB) and amorphous polyhydroxyalkanoate (PHA) were prepared. PHB/PHA films displayed Young modulus of 240 MPa, tensile strength at a maximum of 6.6 MPa and elongation at break of 95.2%. The physical properties of PHB/PHA films were modified by the addition of 1-10 wt% of grape seeds lignin (GS-L). GS-L lignin showed a high antioxidant capacity: 238 milligrams of Trolox equivalents were equal to one gram of grape seeds lignin. The incorporation of grape seeds lignin into PHB/PHA films positively influenced their gas barrier properties, antioxidant activity and biodegradability. The values of oxygen and carbon dioxide transition rate of PHB/PHA with 1 wt% of GS-L were 7.3 and 36.3 cm³ m^-2 24 h 0.1 MPa, respectively. The inhibition percentage of the ABTS radical determined in PHB/PHA/GS-L was in the range of 29.2% to 100% depending on the lignin concentration. The biodegradability test carried out under controlled composting environment for 90 days showed that the PHB/PHA film with 50 w/w% of amorphous PHA reached the degradability degree of 68.8% being about 26.6% higher decomposition than in the case of neat high crystalline PHB film. The degradability degree of PHA films in compost within the tested period reflected the modification of the semi-crystalline character and varied with the incorporated lignin. From the toxicological point of view, the composts obtained after biodegradation of PHA films proved the non-toxicity of PHB/PHA/GS-L materials and its degradation products showed a positive effect on white mustard (Sinapis alba L.) seeds germination.