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The work was supported through the project UIDB/50006/2020, funded by FCT/MCTES through national
funds and by the AgriFood XXI I&D&I project (NORTE-01-0145-FEDER-000041 co-financed by European
Regional Development Fund (ERDF), through the NORTE 2020. N Teixeira and Hiléia Souza thanks FCT
for CEECIND/00025/2018/CP1545/CT0009 and PTDC/OCE-ETA/31250/2017 contracts, respectively.
Acknowledgements
Extraction of polyphenolic compounds
Film production – Casting method
Films with NADES and NADES/GT extracts (10%, 20% and 30% w/w).
Two systems: CH films with and without addition of NADES or
NADES/GT.
Film characterization
Scanning Electron Microscopy (SEM)
Experiments were carried out at
CEMUP, Porto, Portugal.
Water Vapour Permeability (WVP)
Optical properties (colour and opacity)
Swelling Index (SI)
Results and discussion
CH biofilms (with and without binary and ternary NADESs), produced by
casting method, present compact, homogenous and transparent structure.
Ternary NADES (ChCl/lactic acid/glycerol) exhibit great potential to be
used as a plasticizer for polysaccharides biofilms.
The results obtained suggest that, by varying the composition/structure of
these potentially biodegradable films, the morphology as well the water
resistance proprieties of the films can be altered.
Conclusions
References[1]Queiroz,Q.U.B; Collares-Queiroz, F. P. Polymer Reviews 49 (2009) 65-78.
[2] Galvis-Sánchez,A.C., Sousa,A.M.M., Hilliou,L., Gonçalves, M.P. and Souza,H.K.S. . Green Chemistry, 18 (2016), 1571-1580.
[3]Trouillas, P. Sancho-García, J. C., De Dreitas, V., Gierschner, J., Otyepka, M. and Dangles, D. Chemical Reviews, 116 (2016) 4937-4982.
[4]Papuc, C., Goran, G. V., Predescu, C. N., Nicorescu, V. and Stefan, G. Comprehensive Reviews in Food Science and Food Safety 16 (2017) 1243-1268.
Swelling Index (SI)
Similar increase of water retention
capacity evolution was observed.
Despite the process being very fast for
all the samples, it depends on the type of
NADESs used.
Scanning Electron Microscopy (SEM)
Chit
Compact and homogenous microstructures were
observed for chitosan film without plasticizers.
Outer surface of all films show no cracks or pores.
Surface morphologies depending on NADESs type
used.
The presence of GT polyphenols leads to different
surface structures, and so, the surface of the film
becomes rough with the increase of GT content.
NADES1_10% NADES2_10% NADES3_10%
NADES1_GT_10%
5000 X
NADES1_GT_20% NADES1_GT_30%
Water Vapour Permeability (WVP) and Thickness
Films d (mm)WVP
(g-1·s-1Pa-1)x10-10
Chit 0.085±0.006 3.12±0.03
Chit-NADES1-20% 0.077±0.003 3.37±0.15
Chit-NADES2-20% 0.080±0.004 3.90±0.04
Chit -NADES3-20% 0.076±0.007 3.29±0.07
Chit-NADES1-GT 20% 0.078±0.007 3.67±0.01
Chit-NADES2-GT 20% 0.071±0.002 3.79±0.02
Chit-NADES3-GT 20% 0.079±0.004 3.33±0.05
Films prepared with Chit
show higher thickness values
than plasticizer films.
Films with NADES showed
different WVP from the
unplasticized film.
Within films containing
NADES/GT extraction (Ta-
ble 1), the lowest value was
displayed by Chit-NADES3-
GT.
Table 1 - WVP and thickness, d, values of investigated films with 20% of plasticizer.
Optical properties
Addition of NADES had a noticeable impact on biofilm’s colour.
Graphic 2 - Colour parameters for CH films in presence
and absence of NADES or NADES/GT extraction.
Graphic 3 – Opacity parameter for CH films, with and
without addition of NADES or NADES/GT extraction.
Graphic 1 –Swelling Index for CH films in presence and absence of NADES or NADES/GT extraction
Introduction
It is expected that every aspect of industrial manufacturing can shift to
develop environmentally friendly processes in order to obtain functional
materials from biodegradable and naturally abundant resources.
Concerning the bioplastic industry, chitosan (CH) is a very promising
candidate for production of bio-based materials since it is renewable, non-
toxic and biodegradable. CH has been used to develop packaging
applications.[1,2]
Green technologies, such as the use of natural deep eutectic solvents
(NADES), have been recently used as an environmentally friendly media
for plasticizer biofilm and as an extraction medium of bioactive
products.[3,4]
In this work, we report the successful use of binary and ternary NADES as
a multi-functional medium for the extraction of polyphenolic compounds
from green tea (GT). The polyphenols extracted were used for the
production of CH bio-films. Transparent films were obtained and evaluated
in terms of water resistance, optical and microstructural properties and
thermal proprieties. Significant differences were verified in the biofilm's
microstructural properties, hygroscopic and thermal behaviour for the
NASDES type and content considered.
Tiago Filipe P. Alves*, Natércia Teixeira, Victor de Freitas and Hiléia K. S. Souza
Green tea extract and green ionic liquids used as
functional additives for chitosan filmsREQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto,
Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. *Email: [email protected]
Concurso para Projetos de I C&DT
em Todos os Dom ínios Cient íficos
Guia de Apoio ao Preenchim ento do
Form ulár io de Candidatura
2 8 de janeiro de 2 02 1
The films tended to be green (-a*) and yellow (+b*).
NADES-1 films and NADES-2/GT were the most transparent’s biofilms.
NADES:
NADES1 - ChCl/latic acid (LA) 1:2
NADES2 - ChCl/glycerol (Gly) 1:2
NADES3 - ChCl/LA/Gly 1:1:1
CH (3% w/w)
(DD=78%)
pH=5.70
Adjusted with acetic acid
NADES (1,2,3)-GT
extraction