**1.1 Packaging materials covered with active coatings**

The modification of various polymers, including biopolymers, to obtain antimicrobial packaging that mainly includes polymer blending with bioactive components. Unfortunately, the negative effects of thermal processing on active agents during their incorporation into the polymer matrix can be seen. One solution to this problem is the coating of the polymer packaging surface. Fabrication of one-layer, bi-layer, tri-layer, and/or multilayer films through the use of a surface coating/covering technology is a promising strategy to improve the mechanical, barrier, or antimicrobial properties of traditional packaging materials for food packaging. Moreover, the surface coating method is more conducive to the migration of active substances and thus effectively protects the product [9, 10]. In the case of antimicrobial packaging, two important components, namely a polymer-based coating carrier, and an antimicrobial agent are very important. Antimicrobial coatings use many biobased carriers, such as carbohydrates, proteins, and lipids. Carboxymethyl cellulose (CMC) is a water-soluble derivative of cellulose that has the ability to form coatings and films in order to obtain an antimicrobial coating which may lead to increased food shelf-life. CMC is a linear polymer, it is long-chain and high molecular weight, make it a suitable polymer as a coating [11]. Starch as an inexpensive biodegradable polysaccharide is also used as a coating carrier, due to its renewable, nontoxic, multifunctional, biodegradable, and film-forming properties [12]. Among coating carriers, polysaccharides, such
