for an equivalent mass of covalently immobilized lysozyme) with no migration of
lysozyme from the films, suggesting utilization of these films for food packaging
applications [73]. The antimicrobial membranes attained from polyamide 11(PA11)
and nano-hybrid composed of halloysite nanotubes (HNTs) filled with lysozyme
were effective as antimicrobial pads for chicken meat storage. The membrane filled
with 5.0 wt% of HNTs-lysozyme reduced the growth of Pseudomonas aeruginosa
for up to 13 days of storage at 4
C [74]. Antilisterial films of lysozyme based on zein
were developed with a consumer-controlled and pH-triggered release mechanism.
During transportation the antimicrobial stress is increased over pathogens in
consumer-controlled release mechanisms [75].
3.1.3 Plants Extracts and Phytochemicals
A great interest has been shown in the utilization of plant extracts for edible polymerbased food packaging applications. Incorporation of phytochemicals into polymerbased packaging material has shown to improve its physiochemical properties. For
example, incorporation of clove, star anise, and cinnamon extracts into hydrolyzed
gelatin film has reduced their water vapor permeability and improved tensile
strength. In a different study, incorporation of grape seed extract (GSE) into soybean
protein isolate films resulted in bactericidal effects against food safety pathogens
including Listeria monocytogenes, Escherichia coli 0157:H7, and Salmonella
typhimurium [76–78]. Antimicrobial activity of plant-based antimicrobial films
may be attributed due to the high phenolic content containing components like
carvacrol, thymol, and eugenol. For example, thymol and carvacrol (8 wt%) have
shown promising application as active additives in polypropylene (PP) films with
dual response of controlled antioxidant and antimicrobial release into food material.
Thus, they can be able to replace synthetic antioxidants employed in PP film
formulations [79]. Nanocomposite antimicrobial films prepared using LDPE and
carvacrol have displayed remarkable oxygen barrier property and thermal stability
with significant antimicrobial activity against Pseudomonas stains [79]. In another
study, five chitosan-based films containing carvacrol showed antimicrobial activity
against Bacillus subtilis, Escherichia coli, Listeria innocua, and Salmonella
enteritidis. The minimal vapor inhibitory concentration obtained for S. enteritidis
was 1.08 Â 10
À7 g mL
À1 (K mass ¼ 1.01 Â 10
À4 ), and for B. subtilis, E. coli, and
L. innocua, it was 4.62 Â 10
À8 g mL
À1 (K mass ¼ 1.13 Â 10
À6 ), respectively.
Carvacrol-activated active films have displayed antimicrobial effect at their vapor
phase against bacterial pathogens [80].
3.1.4 Essential Oils
Essential oil incorporation into packaging system reduces transparency and
improves the antimicrobial and water barrier properties. Essential oils extracted
from plants and spices such as cumin, fennel, laurel, mint, sage, savory, garlic,
Recent Developments in Food-Based Bioplastics Production
119
lysozyme from the films, suggesting utilization of these films for food packaging
applications [73]. The antimicrobial membranes attained from polyamide 11(PA11)
and nano-hybrid composed of halloysite nanotubes (HNTs) filled with lysozyme
were effective as antimicrobial pads for chicken meat storage. The membrane filled
with 5.0 wt% of HNTs-lysozyme reduced the growth of Pseudomonas aeruginosa
for up to 13 days of storage at 4
C [74]. Antilisterial films of lysozyme based on zein
were developed with a consumer-controlled and pH-triggered release mechanism.
During transportation the antimicrobial stress is increased over pathogens in
consumer-controlled release mechanisms [75].
3.1.3 Plants Extracts and Phytochemicals
A great interest has been shown in the utilization of plant extracts for edible polymerbased food packaging applications. Incorporation of phytochemicals into polymerbased packaging material has shown to improve its physiochemical properties. For
example, incorporation of clove, star anise, and cinnamon extracts into hydrolyzed
gelatin film has reduced their water vapor permeability and improved tensile
strength. In a different study, incorporation of grape seed extract (GSE) into soybean
protein isolate films resulted in bactericidal effects against food safety pathogens
including Listeria monocytogenes, Escherichia coli 0157:H7, and Salmonella
typhimurium [76–78]. Antimicrobial activity of plant-based antimicrobial films
may be attributed due to the high phenolic content containing components like
carvacrol, thymol, and eugenol. For example, thymol and carvacrol (8 wt%) have
shown promising application as active additives in polypropylene (PP) films with
dual response of controlled antioxidant and antimicrobial release into food material.
Thus, they can be able to replace synthetic antioxidants employed in PP film
formulations [79]. Nanocomposite antimicrobial films prepared using LDPE and
carvacrol have displayed remarkable oxygen barrier property and thermal stability
with significant antimicrobial activity against Pseudomonas stains [79]. In another
study, five chitosan-based films containing carvacrol showed antimicrobial activity
against Bacillus subtilis, Escherichia coli, Listeria innocua, and Salmonella
enteritidis. The minimal vapor inhibitory concentration obtained for S. enteritidis
was 1.08 Â 10
À7 g mL
À1 (K mass ¼ 1.01 Â 10
À4 ), and for B. subtilis, E. coli, and
L. innocua, it was 4.62 Â 10
À8 g mL
À1 (K mass ¼ 1.13 Â 10
À6 ), respectively.
Carvacrol-activated active films have displayed antimicrobial effect at their vapor
phase against bacterial pathogens [80].
3.1.4 Essential Oils
Essential oil incorporation into packaging system reduces transparency and
improves the antimicrobial and water barrier properties. Essential oils extracted
from plants and spices such as cumin, fennel, laurel, mint, sage, savory, garlic,
Recent Developments in Food-Based Bioplastics Production
119