## 1 Introduction  
The preservation of food is greatly influenced by the role of food packaging, which shields it from chemical, biological, environmental, and physical harm during transportation and storage. Effective food packaging ensures the safe distribution of products to consumers in optimal conditions. In addition, microbial contamination causes food to spoil and is responsible for over 25% of food lost before it is consumed [1]. The excessive use of petroleum-based plastics has led to serious environmental problems, with annual global plastic production exceeding 350 million tons. Alarmingly, our oceans contain approximately 85% of plastic waste, posing a serious threat to the environment and human health [2]. Food packaging accounts for approximately 45% of non-biodegradable plastics [3]. In response to growing environmental concerns and the demand for natural compounds, scientists have been focused on developing biodegradable food packaging with biological activities due to their environmentally friendly properties. Biopolymer-based materials derived from plant, animal, and microbial sources have attracted attention. These materials can be enzymatically degraded by microbes [4]. Over the past two decades, extensive research has been conducted on biopolymers for food packaging applications as alternatives to petroleum-based plastics [5, 6]. Biopolymer packaging materials are naturally derived from lipids, proteins, or polysaccharides [7]. Among these, polysaccharides such as cellulose, alginate, starch, chitosan, pectin, gum, carrageenanan, and pullulan have great potential for the development of food packaging [8; 9]. In particular, pectin has attracted considerable attention. Pectin is a group of structurally heterogeneous polysaccharideswidely distributed in the primary cell walls and middle lamella of plants. It consists of \(\beta\)-(1-4)-linked D-galacturonic acid with galactose and rhamn [10]. Its structural and macromolecular properties vary depending on the used source [5]. Although apple pomace and citrus peel are the primary sources for commercial pectin production, there is an increasing demand for alternative sources to obtain pectin with different functional groups by more effectively utilizing food by-products [11; 12]. Pectins have the carboxyl group of the sugar moiety in their structure, which may be partially esterified with a methyl group and partially or completely neutralized with one or more bases [13]. Based on the degree of esterification (DE), pectin can be classified to low methyl pectin (LMP) with less than 50% esterification and high methyl pectin (HMP) with more than 50% esterification [11]. The pectin properties depend on many factors, mostly including the source, extraction method, molecular weight, degree of methyl esterification, etc. [13]. Gel formation is one of the most important properties of pectin. LMP forms gel in the presence of calcium ions, which involves electrostatic interactions resulting in the formation of an eggbox model stabilized by hydrogen bonds and van der Waals interactions between the methylated groups and free carboxyl groups [14]. To prepare a pectin film-forming gel with adequate mechanical strength, rupture strength and viscosity, the molecular weight needs to be more than 300 kDa [13]. In the food industry, pectin finds various uses as a gelling agent, thickening agent, and stabilizer. Additionally, its applications extend beyond food to non-food sectors like the medical and pharmaceutical industries [11]. Due to its excellent film-forming properties, biocompatibility, biodegradability and non-toxicity, pectin is considered also an effective biopolymer for the production of film packaging [15]. Pectin-based films can be produced by different techniques such as solution casting and extrusion [16]. Because of its simplicity and the fact that it does not require special tools, solution casting is the most commonly used method on a laboratory scale [13].