19
coliforms in cheese packaged with this material. The active TiO 2 NP-loaded
LLDPE-based films can also inactivate Pseudomonas spp. and Rhodotorula mucilaginosa, thus demonstrating that these materials can potentially be used for fruit
packaging applications (Bodaghi et al. 2013).
As mentioned above, active polymers can be obtained by including both types
of particles: active by themselves or active agent carriers. Keeping this in mind, the
use of clay minerals has also received great attention because they can be incorporated into packaging materials to include specific activities or functionalities. The
common natural clays are low-cost and toxin-free materials, which are widely used
in many fields. The active clay-loaded polymer nanocomposite films have also
been shown to improve the barrier, mechanical, physical and thermal properties
(Shankar and Rhim 2016). These clay NPs can also lead to the development of
controlled volatile or active substance release systems, such as EOs, due to their
large surface area and porosity (Campos Requena et al. 2016; Gul et al. 2016). Its
structure includes the stacked arrangement of silicate layers (platelets) and inorganic cations which gives it its hydrophilic character (Gutiérrez et al. 2017) and
efficacy as active agents. For this reason, the clay NPs have been studied for the
development of AP by means of in vitro experiments or directly on foodstuff surfaces (Kuorwel et al. 2015). Concerning nanocomposites, diverse types of nanoclays (e.g. montmorillonite – Mnt and organophilic Mnt) can be used to improve
the characteristics of polymers, resulting in compatible thermoplastic composite
materials because of their large aspect ratio (Bumbudsanpharoke and Ko 2019). In
addition, active nanocomposite films containing certain types of modified Mnts
have a relevant antimicrobial activity against Gram-positive and negative bacteria
(Fasihnia et al. 2017). In this regard, nanoclay-loaded PE-based AP films have
demonstrated high efficiency to prolong the shelf life of foods, such as fruits.
Physiologic changes in fresh foods can be avoided by using modified nanocomposite films, having good antimicrobial and barrier properties, so these materials can
lead to delayed ripening of fruits (Ebrahimi et al. 2018). This can be associated
with quaternary ammonium groups present on the surface of the modified Mnts
(Bumbudsanpharoke and Ko 2019).
On the other hand, the application of clay mineral NPs as carriers for AP has
been widely studied. Antimicrobial materials have been developed by incorporating
various biocidal volatile compounds such as carvacrol, lemon and rosemary EOs,
among others, to clay/polymer nanocomposites (Alonso et al. 2016; Campos
Requena et al. 2016). This type of active polymer films has shown a high efficiency
against bacteria (E. coli and Listeria innocua) and fungi (Alternaria alternata). The
main advantage of these active nanocomposite films is the controlled release capacity of volatile agents, thereby extending their biocidal activity (Shemesh et al. 2015).
It is thus crucial to analyze the retention and desorption mechanisms related to the
absorption and release of the active agent. A better understanding of this phenomenon allows the development of tailored active nanocomposite films. In this way,
many authors have studied the sorption phenomena of volatile compounds from
nanocomposite, considering that these materials are constituted of a permeable
polymer phase and non-permeable NPs. The active agent release is thus restricted to
2 Active Packaging Films Based on Polyolefins Modified by Organic and Inorganic…
coliforms in cheese packaged with this material. The active TiO 2 NP-loaded
LLDPE-based films can also inactivate Pseudomonas spp. and Rhodotorula mucilaginosa, thus demonstrating that these materials can potentially be used for fruit
packaging applications (Bodaghi et al. 2013).
As mentioned above, active polymers can be obtained by including both types
of particles: active by themselves or active agent carriers. Keeping this in mind, the
use of clay minerals has also received great attention because they can be incorporated into packaging materials to include specific activities or functionalities. The
common natural clays are low-cost and toxin-free materials, which are widely used
in many fields. The active clay-loaded polymer nanocomposite films have also
been shown to improve the barrier, mechanical, physical and thermal properties
(Shankar and Rhim 2016). These clay NPs can also lead to the development of
controlled volatile or active substance release systems, such as EOs, due to their
large surface area and porosity (Campos Requena et al. 2016; Gul et al. 2016). Its
structure includes the stacked arrangement of silicate layers (platelets) and inorganic cations which gives it its hydrophilic character (Gutiérrez et al. 2017) and
efficacy as active agents. For this reason, the clay NPs have been studied for the
development of AP by means of in vitro experiments or directly on foodstuff surfaces (Kuorwel et al. 2015). Concerning nanocomposites, diverse types of nanoclays (e.g. montmorillonite – Mnt and organophilic Mnt) can be used to improve
the characteristics of polymers, resulting in compatible thermoplastic composite
materials because of their large aspect ratio (Bumbudsanpharoke and Ko 2019). In
addition, active nanocomposite films containing certain types of modified Mnts
have a relevant antimicrobial activity against Gram-positive and negative bacteria
(Fasihnia et al. 2017). In this regard, nanoclay-loaded PE-based AP films have
demonstrated high efficiency to prolong the shelf life of foods, such as fruits.
Physiologic changes in fresh foods can be avoided by using modified nanocomposite films, having good antimicrobial and barrier properties, so these materials can
lead to delayed ripening of fruits (Ebrahimi et al. 2018). This can be associated
with quaternary ammonium groups present on the surface of the modified Mnts
(Bumbudsanpharoke and Ko 2019).
On the other hand, the application of clay mineral NPs as carriers for AP has
been widely studied. Antimicrobial materials have been developed by incorporating
various biocidal volatile compounds such as carvacrol, lemon and rosemary EOs,
among others, to clay/polymer nanocomposites (Alonso et al. 2016; Campos
Requena et al. 2016). This type of active polymer films has shown a high efficiency
against bacteria (E. coli and Listeria innocua) and fungi (Alternaria alternata). The
main advantage of these active nanocomposite films is the controlled release capacity of volatile agents, thereby extending their biocidal activity (Shemesh et al. 2015).
It is thus crucial to analyze the retention and desorption mechanisms related to the
absorption and release of the active agent. A better understanding of this phenomenon allows the development of tailored active nanocomposite films. In this way,
many authors have studied the sorption phenomena of volatile compounds from
nanocomposite, considering that these materials are constituted of a permeable
polymer phase and non-permeable NPs. The active agent release is thus restricted to
2 Active Packaging Films Based on Polyolefins Modified by Organic and Inorganic…