Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films

first_page settings Order Article Reprints Open AccessArticle Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films by Francesco Bigi 1 [ORCID] , Enrico Maurizzi 1 [ORCID] , Hossein Haghighi 1 [ORCID] , Heinz Wilhelm Siesler 2 [ORCID] , Fabio Licciardello 1,3 [ORCID] and Andrea Pulvirenti 1,3,* [ORCID] 1 Department of Life Sciences, University of Modena and Reggio Emilia, 42015 Reggio Emilia, Italy 2 Department of Physical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany 3 Interdepartmental Research Centre for the Improvement of Agri-Food Biological Resources (BIOGEST-SITEIA), University of Modena and Reggio Emilia, 42015 Reggio Emilia, Italy * Author to whom correspondence should be addressed. Foods 2023, 12(5), 960; https://doi.org/10.3390/foods12050960 Received: 19 January 2023 / Revised: 16 February 2023 / Accepted: 21 February 2023 / Published: 24 February 2023 (This article belongs to the Special Issue Scientific Breakthroughs to Fruit and Vegetable By-Product Valorization in Food Sector) Download Browse Figures Versions Notes Abstract To date, approximately 30–50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE). It was evaluated how CNCs and LAE affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE. The inclusion of CNCs increased the films’ tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE improved the films’ flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica.