**3.1 Wood**

Wood has naturally favorable mechanical, physical, and chemical properties, which makes it an excellent packaging material that possesses a good weight-tostrength ratio, and on the other hand, has a high hydration capacity. Aside from its natural moisture content, wood can absorb or release water in equilibrium with the food with which it comes into direct contact. This is one of the characteristics that, for example, seafood, vegetable, and fruit industries stakeholders seek [20]. Furthermore, the majority of wood species have the naturally occurring acidic pH range of 4.3–5.2, which influences bacterial survival on their surfaces [21]. Wooden materials are less expensive to produce than other containers and are still widely used. Depending on the country's regulations and marketing chains, they can be considered for both single-use and reusable packaging. However, in most applications, plastic containers have largely replaced wooden containers because they are more cost-effective, easier to clean for reuse, and do not risk contaminating foods with slivers. Nevertheless, wood as a material is more renewable and after use represents a lower impact on the environment than plastic [22].

### **3.2 Paper**

Paper-based packaging accounts for more than 30% of the global packaging market and is widely used for the packaging of food products due to its broad range of capabilities at a low cost [23]. The most important aspect of paper packaging is that their inert nature extends the shelf life of packed products. Furthermore, paper and paperboard are easy to recycle and environmentally friendly. This kind of packaging is extensively used for packing a variety of milk and soft drink products, baked goods, and a lot more. The standard paper, on the other hand, cannot be used frequently due to the reduced moisture barrier, which leads to microbial contamination. Furthermore, it lacks mechanical strength, which is required for transportation and storage [24]. There have also been several reports that show safety concerns and toxicity risks. In the year 2004, Ozaki et al. [25] conducted a study involving chemical of concern analysis present in paper packaging. The research stated that abietic acid (AA) and dehydroabietic acid (DHA) of contaminants usually to be reported in paper packaging were found to be toxic and potentially genotoxic at higher concentrations. The food contamination risk by the use of paper-based material in its packaging remains on the table, despite the few reported studies of some sort of paper in a treated form that is widely used for various levels of product packaging including foods [24].

#### **3.3 Polymers**

Food packaging materials have evolved over time, from primitive tree barks to modern plastic packages. Polymeric materials are quite diverse and adaptable. They can be soft or stiff, transparent, or opaque, thermosets, or thermoplastics and can be made into films or containers of various shapes and sizes. They are,

on average, much less expensive and, without a doubt, much lighter. Countless polymers have been chemically synthesized or extracted from natural sources for a variety of applications. The enormous range of development in polymers necessitated their classification on various bases, the most important of which were origin and stiffness [26].
