Active Packaging Antimicrobial Films for Food Packaging

Dr. Selcuk Yildirim

Institut fr Getrnke und Lebensmittel Innovation Life Sciences und Facility Management

Content

Packaging and ist functions

Active packaging

Antimicrobial films & packaging systems

Natural antimicrobial agents

Design of antimicrobial systems

Summary & outlook

Packaging and ist functions

Packaging: A coordinated system of preparing goods for transport, distribution, storage, retailing and use..

Marketing functions Technical functions

Information Contain

Display Transport

Communicate Protect

Convenience Preservation

End of life

Preservation of Food

Passive Role (barrier)

Food

O2

microorganism

chemicals

water vapour

light

Consumer trends - better quality, - Freshness - convenience

New packaging technologies

- shelf life extention - food lost - safe food

Active Packaging

Active Packaging: ..designed to deliberately incorporate components that would release or absorb substances into or from the packaged food or the

environment surrounding the food Regulation (EC) No 1935/2004

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* Yildirim S. Newsletter Transfer, 3-2010, Wdenswil, Switzerland

Active layer

Food

Active Scavenging Systems - Oxygen - CO2 - Moisture - Ethylene - Odor

Active Releasing Systems - Antimicrobial agent

- CO2 - Antioxidant

- Flavours - Ethylene

Barrier layer

Antimicrobial Packaging

A complimentary method to the existing preservation methods to control undesirable microorganisms on foods

Direct addition of antimicrobials could result in some loss of their activities because of their diffusion into the food matrix*

Use of packaging films containing antimicrobial agents could be more efficient than the direct addition of these compounds into the food

Controlled migration of the active compound from the packaging material into the food enable not only the initial inhibition of undesirable microorganisms present in food, but also create a residual activity over time, during transport, storage and distribution of food**

* Han J H and Floros J D (1997), Casting antimicrobial packaging films and measuring their physical properties and antimicrobial activity, J. of Plast. Film & Sheeting, 13, 287-298. ** Cutter C N (2002), Microbial control by packaging: A review, Crit. Rev. Food Sci. Nutr., 42, 151-161

Antimicrobial Packaging Systems

* Yildirim S. Active Packaging for Food Biopreservation in Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation, Ed. Christophe Lacroix, Woodhead, 2011

Food

Barrier layer

Active layer

Antimicrobial agents

Food

Antimicrobial agents

Food

Antimicrobial agents

Barrier layer

Active layer

Barrier layer

Active layer

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Natural Antimicrobial Agents

Natural antimicrobial agents occur in nature or isolated from microbial, plant, or animal sources.

Antimicrobial agents produced by microorganisms include bacteriocins such as nisin or pediocin antibiotics such as natamycin organic acids such as sorbic and benzoic acids enzymes such as lysozyme

Plant origin antimicrobial agents include extracts of spices such as thyme, oregano etc..

Chitosan is an example of natural antimicrobial polymer obtained by deacetylation of chitin obtained commercially from shrimp and crabshell.

Bacteriocins

Bacteriocins are antimicrobial peptides produced by bacteria which inhibit other closely related bacteria.

Nisin is the most common bacteriocin, tested for many applications.* It has been approved for use as a food preservative and was affirmed

GRAS by FDA.

It is non-toxic, heat stable, commercially available and already used for specific applications in a variety of foods

Broader spectrum of antimicrobial activity, including spoilage bacteria and food pathogen.

* Delves-Broughton, J. Nisin, natamycin and other commercial fermentates used in food biopreservation in Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation, Ed. Christophe Lacroix, Woodhead, 2011

Bacteriocins Bacteriocin Packaging Material Food/Media Microorganism

Nisin

Pediocin

Enterocin

Lacticin

Polyolefins/MC/HPM

WPI coated PP

LDPE, PE

Paper board with AP

Pectin/PLA composite

Cellophane

Tofu

Hot dogs

Beef

Milk

Orange juice

Liquid egg

Water

Frankfurter

Ham

Turkey brest

Cheese

Smoked salmon

L. monocytogenes,

L. plantarum

B. thermosphacta

L. helveticus

Carnobacterium spp.

LAB

TAB

Yeast

* Yildirim S. Active Packaging for Food Biopreservation in Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation, Ed. Christophe Lacroix, Woodhead, 2011

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Organic Acids, their salts and anhydrides

AMA Packaging Material

Food/Media Microorganism

Sorbic Acid Benzoic acid Acetic acid Propionic acid Their salts and anhyrides

PVDC MC LDPE, PE Chitosan

Beef Cheese Ham

L. monocytogenes, Penicillum sp. A. niger Enterobacteriaceae L. Sakei Molds

Organic acids are natural constituents of many foods and they have been used for a long time as additives in food preservation

They show none-specific antimicrobial properties against bacteria and fungi. Direct surface application by spraying or dipping may result in reduce or loss of

antimicrobial activity due to a possible reaction with food components, diffusion into the food, and evaporation or instability during food processes.

A more effective way could be the incorporation of organic acids into the packaging followed by release to food which may result in longer term protection of the food.

Packaging films containing organic acids should have a direct contact with the food in order to release the active compounds to the food surface.

Antimicrobial activity of organic acids depends on the dissociation constant pKa

Plant extracts

AMA Packaging Material

Food/Media Microorganism

Cinnamaldehyde Rosemary oil Grapefruit seed extract Linaolol Eugenol, tymol, menthol Oregano oil

SPI coated OPP/PE PE LDPE, PP OPP WPI

Sprouts Beef Ground beef Cheese Grapes

E. Coli Salmonella E. Sakazaki B. Cereus S. Aureus L. Innocua Yeasts Molds TVC

Spice and herbs are important source of antimicrobial agents which are effective against several gram-positive and gram-negative bacteria as well as yeast and fungi

The composition, structure as well as functional groups of the oils play an important role in determining their antimicrobial activity.

Majority of the natural extracts such as essential oils are approved as GRAS by U.S. Food and Drug Administration

Application of essential oils in packaging for food can be limited with their strong flavours.

Enzymes

ILGI

Lysozyme is an antimicrobial enzyme active on beta 1-4 glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine of the bacterial peptidoglycan.

Antimicrobial activity on gram-positive bacteria but not on gram-negative bacteria because of their protective outer membrane surrounding the peptidoglycan layer.

Micrococcus lysodeikticus, Alicyclobacillus acidoterrestris Glucose oxidase itself does not possess antimicrobial activity, but the products

from the reaction exhibit antimicrobial power.

Glucose oxidases the formation of H2O2 and D-glucono--lactone, which then reacts with H2O to form D-gluconic acid.

The antimicrobial activity of the system is due to the cytotoxicity of the H2O2 formed, although the lowering of pH by the production of D-gluconic acid may also

influence the growth of some microorganisms

Escherichia coli and Bacillus subtilis Limitations: High cost, requirement of glucose, stability of enzyme activity, low

tolrance of enzymes to high temperature.

Chemical agents

According to the EU regulations (Commission regulation (EC) No 450/2009) active agents that are incorporated into the packaging material to be released into the food

should comply the legislation on food additives.

Chemical antimicrobial agents that are released from the packaging into the food or its environment should be food grade chemicals.

Non-food grade chemicals can be incorporated into packaging if they are not released into the food (specific migrations).

Fungicides such as imazalil and benomyl

Silver in polymers as an antimicrobial agent

Several silver-ion containing zeolite or glass systems have been incorporated into many polymers, such as polyethylene, polypropylene, and polyamide and become

commercially available

Design of Antimicrobial Systems

Development and design of an efficient antimicrobial packaging requires an interdisciplinary approach which involves advances in food technology, microbiology,

biotechnology, chemistry and packaging and material sciences.

Antimicrobial agent should be selected carefully according to several issues

An appropriate incorporation method should be developed according to the selected antimicrobial agent and food application.

Regulatory requirements, cost and quality control issues should be taken into consideration for a successful introduction of the antimicrobial films on the market

Design of Antimicrobial Systems Appropriate antimicrobial agent

Source Natural, chemical

Antimicrobial spectrum Gram-positive, gram negative, yeasts, molds, specific bacteria

Antimicrobial activity Required antimicrobial activity, microbial load on food, shelf life of food Stability of activity

Stability of antimicrobial agents Inactivation of antimicrobial agents by food components, dilution of antimicrobial agent in food, loss of activity due to the storage conditions

Effect of antimicrobial activity on the organoleptic properties of food

Color, Texture, flavour

Impacts of antimicrobial packaging on environment

Production of AM agents, incorporation process, diposal of packaging, recyclability

Design of Antimicrobial Systems Incorporation of antimicrobial agents

Incompatibility Incompatibility with packaging

Incorporation process Extrusion, coating, immobilization

Stability of AMA during processing

Heat, chemical reaction, mechanical energy input

Contamination of process environment

Contamination of machines and materials

Mass transfer of antimicrobial agent

Diffusion of AMA through the film, release rate of AMA from the packaging

Effects of AMA on the properties of the packaging film

Physical and Mechanical properties

Barrier properties, Stiffness, tensile strength, coefficient of friction, sealing and pealing properties

Design of Antimicrobial Systems Regulatory requirements

Legislation on packaging and food

Active packaging regulations, legislation of food additives, specific migration limitations

Quality controll

Stability of AMA during supply chain

Storage, transportation, retailers

Quality control systems QC after production, converting process and at food packers

Cost

Material cost Cost of AMA, packaging, processing material

Production cost Cost of production of AMA, economy of scale, requirements of investments

Antimicrobial agent

Incorporation method

AM agent - packaging interactions

Regulatory requirements

Quality Control

Cost

Summary & Outlook Incorporation of AMA into packaging is an interesting development, which allows to combine

the preservative function of antimicrobials with the protective function of packaging

Natural antimicrobial agents have high potential for commercial food packaging applications and would be preferred by the consumers to produce safer food

There is still a big gap between research and commercial applications

AMA of packaging systems have been mainly tested with laboratory media, with only few studies carried out with food systems

To demonstrate the real potential of natural AMA for packaging applications, their AMA should be proven with food systems under real storage and distribution conditions

Additional to the antimicrobial functionality, antimicrobial packaging should fulfil several technical, economical, marketing and regulatory requirements.

Interdisciplinary approach is necessary to support further developments in this area

Collaborative research activities between research institutes and food and packaging companies will pave the way for future commercial applications.

Research Areas of Center of Food Tehnology and Process Engineering @ ZHAW

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Active Packaging

- Antimicrobial films

- Oxygen Scavengers

- Ethylene Scavengers

- Moisture Scavengers

New Packaging Processes

- Modified atmosphere packaging

- Equilibrium atmosphere packaging

- Aseptic packaging

Packaging in Food Processing

- Integration of packaging in food processing

Packaging Simulations

- Shelf life simulations

- Packaging material simulations

Thank you for your attention

Dr. Selcuk Yildirim Institut fr Lebensmittel- und Getrnkeinnovation

Campus Reidbach Postfach Wdenswil

selcuk.yildirim@zhaw.ch Tel: +41 58 934 56 31