14
2.5 Active Film Packaging Based on Polyolefin and NP
2.5.1 Antimicrobial and Repellent Activity by Incorporating
Organic Particles
Most food preservatives, traditionally used in the food industry, are antimicrobial
organic compounds marketed in powder form (Silva and Lidon 2016). There is a
wide variety of these agents, including particles with intrinsic activity and those
acting as antimicrobial agent carriers, mainly liquids. The first group includes
organic compounds of synthetic origin such as acetic, benzoic, propionic and sorbic
acids; antibiotics (e.g. triclosan); benzoates; benzoic, propionic and sorbic anhydrides; chelating agents (e.g. ethylenediaminetetraacetic acid); fungicides (e.g.
benomyl and imazalil); parabens (e.g. ethyl paraben and propyl paraben); propionates; sorbates, among others. Meanwhile, naturally occurring antimicrobial agents,
whether from vegetal or animal sources, are alginate and chitosan (Cs) NPs, antimicrobial peptides, encapsulated EOs, lauric acid, lysozyme, natamycin, nisin, among
others (Davidson et al. 2013; Rai et al. 2016; Vishwakarma et al. 2016; Nakazato
et al. 2017; Pisoschi et al. 2018; Zanetti et al. 2018). The second group includes
materials of high absorption and retention capacity such as microcrystalline cellulose, wood flour, fibers, starch particles, among others (Khosravi et al. 2020). Some
of them are conventionally used as excipients and can be employed as a support of
active agents such as antimicrobial EOs and repellents, thus improving their active
performance (Rani et al. 2013; Urbankova et al. 2015; Rozenblit et al. 2018). The
incorporation of these active agents into the packaging system prolongs the food
shelf-life even more than when they are added directly to it. As a result, this application form improves the agent’s efficiency and effectiveness (Malhotra et al. 2015).
Polymer films containing traditional food preservatives have been used to manufacture AP. The main advantages of these active agents are their commercial availability, ease of handling, low cost, as well as being food grade (generally recognized
as safe – GRAS), water soluble and effective against a broad spectrum of bacteria
and fungi. However, the pH of foods becomes a limitation of the active efficiency.
The antimicrobial mechanism of organic acids and their salts is based on the cell
membrane penetration by the undissociated molecules. For this reason, they are
suitable only for food with a specific acidity range (Espitia et al. 2016; Hauser et al.
2016). In this sense, different strategies have been studied for its incorporation as an
active agent in polyolefin films. For example, Thanakkasaranee et al. (2018) proposed active sodium propionate/PP composite films obtained via extrusion for use
as a bread packaging material. These authors indicated that all composite films containing 5% w/w sodium propionate showed improved antimicrobial, mechanical
and thermal properties compared to pure PP films (Thanakkasaranee et al. 2018).
The composite films achieved a reduction against E. coli and S. aureus by more than
90%. A similar study was developed by Fasihnia et al. (2018) via extrusion to obtain
sorbic acid/PP composite films, which showed effective antimicrobial activity as
food packaging against Aspergillus niger, E. coli and S. aureus. A significant
Y. N. Alonso et al.
2.5 Active Film Packaging Based on Polyolefin and NP
2.5.1 Antimicrobial and Repellent Activity by Incorporating
Organic Particles
Most food preservatives, traditionally used in the food industry, are antimicrobial
organic compounds marketed in powder form (Silva and Lidon 2016). There is a
wide variety of these agents, including particles with intrinsic activity and those
acting as antimicrobial agent carriers, mainly liquids. The first group includes
organic compounds of synthetic origin such as acetic, benzoic, propionic and sorbic
acids; antibiotics (e.g. triclosan); benzoates; benzoic, propionic and sorbic anhydrides; chelating agents (e.g. ethylenediaminetetraacetic acid); fungicides (e.g.
benomyl and imazalil); parabens (e.g. ethyl paraben and propyl paraben); propionates; sorbates, among others. Meanwhile, naturally occurring antimicrobial agents,
whether from vegetal or animal sources, are alginate and chitosan (Cs) NPs, antimicrobial peptides, encapsulated EOs, lauric acid, lysozyme, natamycin, nisin, among
others (Davidson et al. 2013; Rai et al. 2016; Vishwakarma et al. 2016; Nakazato
et al. 2017; Pisoschi et al. 2018; Zanetti et al. 2018). The second group includes
materials of high absorption and retention capacity such as microcrystalline cellulose, wood flour, fibers, starch particles, among others (Khosravi et al. 2020). Some
of them are conventionally used as excipients and can be employed as a support of
active agents such as antimicrobial EOs and repellents, thus improving their active
performance (Rani et al. 2013; Urbankova et al. 2015; Rozenblit et al. 2018). The
incorporation of these active agents into the packaging system prolongs the food
shelf-life even more than when they are added directly to it. As a result, this application form improves the agent’s efficiency and effectiveness (Malhotra et al. 2015).
Polymer films containing traditional food preservatives have been used to manufacture AP. The main advantages of these active agents are their commercial availability, ease of handling, low cost, as well as being food grade (generally recognized
as safe – GRAS), water soluble and effective against a broad spectrum of bacteria
and fungi. However, the pH of foods becomes a limitation of the active efficiency.
The antimicrobial mechanism of organic acids and their salts is based on the cell
membrane penetration by the undissociated molecules. For this reason, they are
suitable only for food with a specific acidity range (Espitia et al. 2016; Hauser et al.
2016). In this sense, different strategies have been studied for its incorporation as an
active agent in polyolefin films. For example, Thanakkasaranee et al. (2018) proposed active sodium propionate/PP composite films obtained via extrusion for use
as a bread packaging material. These authors indicated that all composite films containing 5% w/w sodium propionate showed improved antimicrobial, mechanical
and thermal properties compared to pure PP films (Thanakkasaranee et al. 2018).
The composite films achieved a reduction against E. coli and S. aureus by more than
90%. A similar study was developed by Fasihnia et al. (2018) via extrusion to obtain
sorbic acid/PP composite films, which showed effective antimicrobial activity as
food packaging against Aspergillus niger, E. coli and S. aureus. A significant
Y. N. Alonso et al.