# The Role of Microorganisms and Their Antibacterial Compounds in Food Biopreservation
## 6 New Technologies of Food Bioconversion as an Alternative to Artificial Preservation
Active packaging is a promising technology that actively modifies the internal environment of the food product package by interacting with the food over the storage time. Also, it is defined as an intelligent packaging system that alters and modifies the environment inside the package, and consequently, the state of the food system in \begin{table}
\begin{tabular}{l c c} \hline \hline  & **Biopreservation** &
\begin{tabular}{c} **Physicochemical** \\ **Preservation** \\ \end{tabular} & **Combined Methods** \\ \hline Extended shelf life & X & X & X \\ Safety & X & X & X \\ Milder physicochemical processing & X & - & X \\ Better nutritional value & X & - & X \\ Better performance & X & - & X \\ Reduction of chemical preservatives & X & - & X \\ Avoidance of toxic and cardiogenic compounds & X & - & X \\ Antimicrobial packaging & X & - & X \\ Consumer acceptance & X & - & X \\ Future perspective and development & X & X & X \\ Inactivation of desirable microorganisms & X & X & X \\ (fermentation cultures, probiotics) & & - & X \\ Risk of transferring virulence factors & X & - & X \\ Development of resistance & X & - & X \\ \hline \hline \end{tabular} Explanatory notes: “X”- present, “-” absent.  
\end{table} 
Table 4: Advantages of food biopreservation and combined methods in comparison with physicochemical preservation according to [PERSON] [108], [PERSON] [47], [PERSON] [48], [PERSON] [8], and [PERSON] [71]. order to improve the food quality and extend the shelf life of the product [116]. There are two main methods of using bacteriocins in food-packaging applications: (1) in situ, by incorporating bacteriocin-producing bacteria [117], or (2) ex situ with the addition of purified or semi-purified bacteriocin or bacteriocin-like substances [118; 119]. The incorporation of bacteriocins into the packaging of the food product ensures continuous protection against the external impurities and inhibits the development of microorganisms inside the package [120]. Several ways of creating this type of packaging containing bacteriocins have also been developed: (1) including biostatic substances in the structure of the polymer (or paper), constituting the packaging by means of melting, extrusion, or the use of a solvent [120; 121], (2) adsorption on the surface of the material of the antimicrobial compound [122; 123], and (3) creating covalent or ionic bonds between the polymer and the antimicrobial component, using a polymer with antimicrobial activity, such as chitosan [124; 125; 126]. Nowadays, many biodegradable and edible biopolymers are developed, including materials with antimicrobial properties such as chitosan or polylactic acid (PLA). Those natural biopolymers, due to mechanical strength and low toxicity, are suitable for food packaging. Moreover, incorporation into the packaging of bacteriocins, antioxidants, antimicrobial compounds (polyphenols, tannins, flavonoids, gallic and ferulic acid, silver nanoparticles), ROS scavengers, or moisture absorbents can contribute to additional positive effects on food safety and quality [127]. By using antimicrobial materials or the antibacterial qualities of the polymer it is comprised of, antimicrobial packaging can prevent or limit the growth of unwanted microorganisms [128]. The use of postbiotics in active packaging systems may concern a single postbiotic or a mixture thereof. The new packaging techniques give wide possibilities for application in the food industry and are interesting alternatives for plastic and synthetic gasoline polymers. This antimicrobial-combined packaging technology allows for continuous interactive biopreservation achieved by the controlled release of antimicrobial agents delaying the spoilage of packaged food [56]. Another technological solution is to include antimicrobial agents in the active packaging in the form of a mixture of mainly cell-free supernatant (CFS, cell-free supernatant), which is the fluid formed as a result of the centrifugation of liquids after bacterial cell culture.