Research Article
Production of Pectin-Cellulose Biofilms: A New Approach for
Citrus Waste Recycling
Veronika Bátori, Mostafa Jabbari, Dan Åkesson, Patrik R. Lennartsson,
Mohammad J. Taherzadeh, and Akram Zamani
Swedish Centre for Resource Recovery, University of Bor˚ as, 50190 Bor˚ as, Sweden
Correspondence should be addressed to Veronika B´ atori; veronika.batori@hb.se
Received 24 July 2017; Revised 23 September 2017; Accepted 28 September 2017; Published 29 October 2017
Academic Editor: Arthur J. Ragauskas
Copyright © 2017 Veronika B´ atori et al. his is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for
ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. his
paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable ilm,
for example, for food packaging. Orange waste has been investigated for bioilm production, using the gelling ability of pectin
and the strength of cellulosic ibres. A casting method was used to form a ilm from the previously washed, dried, and milled
orange waste. Two ilm-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images conirmed
a smoother ilm morphology when the incubator shaker was used for drying. he tensile strength of the ilms was 31.67 ± 4.21
and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried ilms, which is within the range of diferent commodity
plastics. Additionally, biodegradability of the ilms was conirmed under anaerobic conditions. Films showed an opaque appearance
with yellowish colour.
1. Introduction
Plastics production has increased enormously in the past
100 years, and a global production of 322 million tons was
reported by Statista [1] for 2015. his vast number of plastic
products caused severe plastic pollution by now and they are
typically made from nonrenewable sources. On the contrary,
bioplastics are made from renewable sources or they are
biodegradable; in the best-case scenario, they are both. Today,
biopolymers are produced from cultivated crops; however,
the land used for bioplastic is still negligible [2].
An example for a biobased and biodegradable material
that is built up of diferent biopolymers, with no land use,
is citrus waste. Citrus waste is a globally abundant and
environmentally challenging waste that is underutilized [3].
Among citrus fruits, sweet oranges are the most commonly
grown tropical fruits worldwide [4]. USDA [5] forecasted
45.8 million tons of sweet orange production for 2015/16.
Industrial orange processing, for example, orange juice pro-
duction generates about 50–60% residue of the original mass
of the orange [6]. his vast quantity of waste is high in
organic matter content (approx. 95% of total solids) and water
(approx. 80–90%) and has a low pH (3-4) and inappropriate
handling could cause severe damage to the environment [6].
Orange waste also contains pectin, soluble sugars, hemi-
celluloses, cellulose, starch, protein, lignin, ash, fat, and
lavonoids [7, 8], which have been shown to be beneicial to
many yet imperfect disposal and recovery applications [6].
hese compounds on the other hand could be interesting for
bioplastics applications.
Orange waste has already been applied as a reinforcement
in petrochemical or biobased matrices [9–11]. In all of these
cases, the authors reported increased mechanical properties
of the products compared to the neat polymer. he increased
mechanical properties are most probably the direct efect
of the present cellulosic ibres. However, pectin, the major
component of orange peel, seems to have no signiicant
efect in the above-mentioned composites. Nevertheless,
pectin-based composites have been prepared with diferent
reinforcing substances [12] and cellulosic plant ibres have
Hindawi
International Journal of Polymer Science
Volume 2017, Article ID 9732329, 9 pages
https://doi.org/10.1155/2017/9732329