system. This would ensure microbial food safety for consumer and also helps in
extension of food’s shelf life.
The mechanism of action in antimicrobial film may be migrating or
non-migrating, it depends on the interaction between food matrix and the packaging.
The antimicrobial agents can be infused in vapor or gradually diffused through food
surface for migrating film applications, whereas it can be applied over the surface for
non-migrating film applications. The release of active antimicrobial compounds in
the food packaging should be tightly regulated and controlled; otherwise it might
pose a safety risk to consumers.
3.1.1 Bacteriocins
Bacteriocins are peptidicantimicrobials which are synthesized mostly by lactic acidproducing bacteria and show bactericidal activity against major food pathogens.
Bacteriocins can be used in antimicrobial packaging to improve product quality,
safety, and shelf life as their use in food has been well recognized by the US FDA,
WHO, and FAO. For example, the population of lactic acid bacteria has been
reduced many folds in ham and sliced cheese stored at refrigerated temperatures,
when they were applied with antimicrobial agent like immobilized bacteriocins
lacticin 3,147 and nisin, thereby extending the shelf life. In a different study,
low-density polyethylene film coated with sonorensin, a subfamily of bacteriocins,
effectively reduced growth of Gram-positive food spoilage bacterial pathogens like
Listeria monocytogenes and S. aureus in chicken meat and tomato samples
[68]. Recently, Emiliano et al. demonstrated that triticale flour films with bacteriocin
like substance effectively controlled the growth of Listeria innocua in food packaging containers [69]. Natamycin-based anti-fungal coating is commercially available
under the brand name SANICO® to be used in cheese and sausages [70].
3.1.2 Enzymes
Enzyme immobilization can be employed as an effective system for antimicrobialbased food packaging. Lysozyme has been permitted to be used as antimicrobial
agent by the US FDA, and its use as a food additives falls under Directive 94/2/EC.
Lysozyme is a single peptide protein which targets and destroys the glyosidic
linkages in the peptidoglycans of Gram-positive bacteria. Cellulose triacetate
(CTA) films immobilized with lysozyme have reduced M. lysodeikticus cell numbers
by 7 log cycles (equivalent mass) within 24 h, suggesting its potential for food
packaging applications [71]. In a different study, lysozyme-chitosan composite films
incorporated with 60% lysozyme have reduced Streptococcus faecalis and E. coli by
3.8 and 2.7 log cycles (equivalent mass), respectively [72]. The covalent immobilization of lysozyme over the surface of ethanol vinyl alcohol copolymers have
reduced the growth of Gram-positive Listeria monocytogenes (1.08 log reduction
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B. Srinivasan and G. Kulshreshtha
extension of food’s shelf life.
The mechanism of action in antimicrobial film may be migrating or
non-migrating, it depends on the interaction between food matrix and the packaging.
The antimicrobial agents can be infused in vapor or gradually diffused through food
surface for migrating film applications, whereas it can be applied over the surface for
non-migrating film applications. The release of active antimicrobial compounds in
the food packaging should be tightly regulated and controlled; otherwise it might
pose a safety risk to consumers.
3.1.1 Bacteriocins
Bacteriocins are peptidicantimicrobials which are synthesized mostly by lactic acidproducing bacteria and show bactericidal activity against major food pathogens.
Bacteriocins can be used in antimicrobial packaging to improve product quality,
safety, and shelf life as their use in food has been well recognized by the US FDA,
WHO, and FAO. For example, the population of lactic acid bacteria has been
reduced many folds in ham and sliced cheese stored at refrigerated temperatures,
when they were applied with antimicrobial agent like immobilized bacteriocins
lacticin 3,147 and nisin, thereby extending the shelf life. In a different study,
low-density polyethylene film coated with sonorensin, a subfamily of bacteriocins,
effectively reduced growth of Gram-positive food spoilage bacterial pathogens like
Listeria monocytogenes and S. aureus in chicken meat and tomato samples
[68]. Recently, Emiliano et al. demonstrated that triticale flour films with bacteriocin
like substance effectively controlled the growth of Listeria innocua in food packaging containers [69]. Natamycin-based anti-fungal coating is commercially available
under the brand name SANICO® to be used in cheese and sausages [70].
3.1.2 Enzymes
Enzyme immobilization can be employed as an effective system for antimicrobialbased food packaging. Lysozyme has been permitted to be used as antimicrobial
agent by the US FDA, and its use as a food additives falls under Directive 94/2/EC.
Lysozyme is a single peptide protein which targets and destroys the glyosidic
linkages in the peptidoglycans of Gram-positive bacteria. Cellulose triacetate
(CTA) films immobilized with lysozyme have reduced M. lysodeikticus cell numbers
by 7 log cycles (equivalent mass) within 24 h, suggesting its potential for food
packaging applications [71]. In a different study, lysozyme-chitosan composite films
incorporated with 60% lysozyme have reduced Streptococcus faecalis and E. coli by
3.8 and 2.7 log cycles (equivalent mass), respectively [72]. The covalent immobilization of lysozyme over the surface of ethanol vinyl alcohol copolymers have
reduced the growth of Gram-positive Listeria monocytogenes (1.08 log reduction
118
B. Srinivasan and G. Kulshreshtha