be exploited by the aerobic microorganisms for their growth. The water activity of
food can further influence the antimicrobial activity and chemical stability of
incorporated active compounds considering the fact of every food having its own
microflora. The rate of diffusion of potassium sorbate in MC/HPMC film containing
saturated fatty acids was found to be high at higher values of free water. With respect
to the contaminating microbe, designing of the release kinetics of antimicrobial
agents should be done in a way that keeps up the concentration on top of the
essential inhibitory concentration (Phakawat et al. 2015).
15.3.3 Interactions of Chemical Additives with Film Matrix
The polarity and mass of additive has to be considered necessarily during
incorporation of additives into a polymer. Additives with high molecular weight
and low polarity have extra compatibility with the non-polar LDPE. The diffusion
rates of different additives within the polymer depend upon their ionic charge,
molecular weight, and solubility. Recently, the diffusion of antioxidant, sodium
ascorbate, and potassium sorbate in calcium-alginate films at 8
C, 15
C, and
23
C was analyzed and experimented by some researchers. They found that
antioxidant activity is the highest with sodium ascorbate and lowest diffusion rates
at all the studied temperatures (Phakawat et al. 2015).
15.3.4 Storage Temperature
The antimicrobial activity of chemical preservatives may also be affected by the
storage temperature. Usually, increase in storage temperature will result in high
diffusion rates within the polymer leading to acceleration of active agent’s migration
within the film and deterioration of protective action of antimicrobial films (Elahe et
al. 2018). The impact of temperature conditions on the antimicrobial activity of
active compounds, their rate of diffusion, and the concentration within the film
throughout production should be predicted in a way that sufficient temperature is
maintained effectively throughout the product’s life (Volpe et al. 2017). Few
demonstrations by certain researchers state that low-density polyethylene (LDPE)
containing low amounts of carboxylic acid anhydrides can be effective both at very
low and high temperature (Kenneth 2017).
15.3.5 Mass Transfer Coefficients
Diffusion stands to be the most elementary system in facilitating release of active
ingredient from packaging material into the food system. The advantages of using a
multilayer packaging are that the antimicrobials are present in an additional skinny
layer, their migration and release being controlled by the film density. It is also very
important to manage the rate of migration of active substances from the food
15 Film Based Packaging for Food Safety and Preservation: Issues and Perspectives
319
food can further influence the antimicrobial activity and chemical stability of
incorporated active compounds considering the fact of every food having its own
microflora. The rate of diffusion of potassium sorbate in MC/HPMC film containing
saturated fatty acids was found to be high at higher values of free water. With respect
to the contaminating microbe, designing of the release kinetics of antimicrobial
agents should be done in a way that keeps up the concentration on top of the
essential inhibitory concentration (Phakawat et al. 2015).
15.3.3 Interactions of Chemical Additives with Film Matrix
The polarity and mass of additive has to be considered necessarily during
incorporation of additives into a polymer. Additives with high molecular weight
and low polarity have extra compatibility with the non-polar LDPE. The diffusion
rates of different additives within the polymer depend upon their ionic charge,
molecular weight, and solubility. Recently, the diffusion of antioxidant, sodium
ascorbate, and potassium sorbate in calcium-alginate films at 8
C, 15
C, and
23
C was analyzed and experimented by some researchers. They found that
antioxidant activity is the highest with sodium ascorbate and lowest diffusion rates
at all the studied temperatures (Phakawat et al. 2015).
15.3.4 Storage Temperature
The antimicrobial activity of chemical preservatives may also be affected by the
storage temperature. Usually, increase in storage temperature will result in high
diffusion rates within the polymer leading to acceleration of active agent’s migration
within the film and deterioration of protective action of antimicrobial films (Elahe et
al. 2018). The impact of temperature conditions on the antimicrobial activity of
active compounds, their rate of diffusion, and the concentration within the film
throughout production should be predicted in a way that sufficient temperature is
maintained effectively throughout the product’s life (Volpe et al. 2017). Few
demonstrations by certain researchers state that low-density polyethylene (LDPE)
containing low amounts of carboxylic acid anhydrides can be effective both at very
low and high temperature (Kenneth 2017).
15.3.5 Mass Transfer Coefficients
Diffusion stands to be the most elementary system in facilitating release of active
ingredient from packaging material into the food system. The advantages of using a
multilayer packaging are that the antimicrobials are present in an additional skinny
layer, their migration and release being controlled by the film density. It is also very
important to manage the rate of migration of active substances from the food
15 Film Based Packaging for Food Safety and Preservation: Issues and Perspectives
319