materials Article Chitosan Edible Films Enhanced with Pomegranate Peel Extract: Study on Physical, Biological, Thermal, and Barrier Properties Nishant Kumar 1, * , Pratibha 2,3 , Anka Trajkovska Petkoska 4 , Ebtihal Khojah 5 , Rokayya Sami 5, * and Amina A. M. Al-Mushhin 6   Citation: Kumar, N.; Pratibha; Trajkovska Petkoska, A.; Khojah, E.; Sami, R.; Al-Mushhin, A.A.M. Chitosan Edible Films Enhanced with Pomegranate Peel Extract: Study on Physical, Biological, Thermal, and Barrier Properties. Materials 2021, 14, 3305. https://doi.org/10.3390/ ma14123305 Academic Editor: Loic Hilliou Received: 13 May 2021 Accepted: 11 June 2021 Published: 15 June 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department of Agricultural and Environmental Sciences, National Institute of Food Technology Entrepreneurship and Management, Sonepat, Kundli 131028, India 2 Department of Food Business Management and Entrepreneurship Development, National Institute of Food Technology Entrepreneurship and Management, Sonepat, Kundli 131028, India; pratibha91coo@gmail.com 3 Department of Humanities and Social Sciences, National Institute of Technology, Kurukshetra 136119, India 4 Faculty of Technology and Technical Sciences, St. Kliment Ohridski University-Bitola, Dimitar Vlahov, 1400 Veles, Republic of North Macedonia; anka.trajkovska@uklo.edu.mk 5 Department of Food Science and Nutrition, College of Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; eykhojah@tu.edu.sa 6 Department of Biology, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia; a.almushhin@psau.edu.sa * Correspondence: nishantniftem@gmail.com (N.K.); rokayya.d@tu.edu.sa (R.S.) Abstract: In the present study, pomegranate peel extract was used as a reinforcing agent in developing chitosan-based edible film. Different concentrations (0.2 g/mL, 0.4 g/mL, 0.6 g/mL, 0.8 g/mL, and 1.0 g/mL) of pomegranate peel extract were incorporated in chitosan-based edible film. A neat chitosan film was used as a control. This work covers the effect of pomegranate peel extract on the physical, biological, mechanical, thermal, and barrier properties of enriched chitosan-based edible film. The results showed that the thickness (0.142–0.159 mm), tensile strength (32.45–35.23 MPa), moisture (11.23–15.28%), opacity (0.039–0.061%), water (1.32–1.60 g·mm/m 2 ), gas barrier properties (93.81–103.45 meq/kg), phenolic content (5.75–32.41 mg/g), and antioxidant activity (23.13–76.54%) of the films increased with increasing volume fraction of pomegranate peel extract. A higher concentration of incorporated pomegranate peel extracts significantly (p < 0.05) reduced the thermal stability of the film, along with its transparency, solubility, swelling, and color. This work revealed that the incorporation of a higher portion of pomegranate peel extract in chitosan film holds significant (p < 0.05) potential for the increase in biological activities of such films in terms of antioxidant and antimicrobial behavior. The properties of pomegranate peel extract-enriched chitosan films could be an excellent cure for free radicals, whereas they could also inhibit the growth of the foodborne pathogens during the processing and preservation of the food. Further studies are needed for the application of pomegranate peel extract-enriched edible films on food products such as fruits and vegetables in order to extend their storage life and improve the quality and safety of preserved food products. Keywords: antimicrobial; chitosan; pomegranate peel extract; antioxidant; edible film; properties 1. Introduction Recently, the increased awareness of consumers has led to the demand for biodegrad- able, edible, and active packaging in the food processing sector. Edible coatings and films are eco-friendly materials that help in a reduction in synthetic-based packaging options and deterioration effects on the environment due to their biodegradable nature and other food protection capabilities [1–5]. Edible coatings and films are also known as a modern food protection system. They provide a good protection of food products in terms of a physical, chemical, and thermal barrier [6], as well as prevention of dehydration (moisture loss) and microorganism contamination in food products in a fresh and frozen form [7]. Materials 2021, 14, 3305. https://doi.org/10.3390/ma14123305 https://www.mdpi.com/journal/materials