This document provides a review of active and intelligent packaging systems for meat and muscle products. It discusses various packaging functions and formats commonly used for meat at retail level. Problems with conventional meat packaging like oxygen exposure and moisture loss are outlined. The document then introduces different types of active packaging technologies, including oxygen scavengers, moisture absorbers, and carbon dioxide emitters/scavengers that can help extend shelf-life. Antimicrobial packaging methods are also reviewed. Finally, the concept of intelligent packaging that can monitor product conditions is introduced.

1. Past, current and potential utilisation of
active and intelligent packaging
systems for meat and muscle-based
products: a review
Joe P. Kerry
Department of Food and Nutritional Sciences,
National University of Ireland,
Cork, Ireland
52nd ICoMST, Dublin, Ireland

2. Meat Packaging
“The efficient containment, preservation and protection of a meat product and all
necessary information required during packing, transport, storage, sale and use, along with the
provision of convenience, taking into consideration all legal and environmental issues”

3. Importance of Meat Packaging at Retail Level
Customer choice of a muscle-based product is dependent upon many factors
Appearance most important
Important meat/pack quality attributes
Meat Colour
Shelf-life Stability
Drip/Moisture Loss
Sensory Attributes
Odour Gain/Loss
Pack Integrity
Pack Appearance
Labelling (dates, additives, product support information)
Convenience

4. Packaging functions (First level packaging)
Technical Function Prevents/Allows:
Free movement of gases
Entry or exit of moisture
Product illumination
Prevent contamination
Sales Function Provides:
Information
Convenience

5. Commercial Meat Packaging Formats
Boxed
Overwrap
Vacuum
Common process
Heat-shrink
Thermoforming vacuum process
Skin vacuum packaging
Modified Atmospheres (MAP)
Retail and bulk gas flushing

6. Problems Associated with Meat Packaging
(First level packaging)
Exposure to oxygen:
Systems generally not hermetic
Meat products exposed to varying levels of oxygen
Moisture loss:
Fresh muscle foods lose moisture in the form of drip-loss
Drip-loss in packs can reduce product shelf-life
Compartmentalised odour/flavour:
Development occurs principally through the production of
volatile gaseous compounds via product-package-gas
interactions

7. Introduction to Active Packaging
(Second level packaging)
Active packaging:
Incorporation of certain additives into packaging systems with the aim of maintaining
or extending product quality and shelf-life
or
Active when it performs some desired role in food preservation other than providing
an inert barrier to external conditions (Hutton, 2003)
or
Active when the packaging elements change the condition of the packed food to extend
shelf-life or improve safety or sensory properties, while maintaining quality of packaged
food (Ahvenainen, 2003)

8. Active packaging applications:
Absorbing/scavenging oxygen, carbon dioxide, moisture,
ethylene, flavours, taints, UV light
Releasing/emitting ethanol, carbon dioxide, antioxidants,
preservatives, sulphur dioxide, flavours, pesticides
Removing catalysing food component removal:
lactose, cholesterol
Temperature control insulating materials, self-heating and self-cooling packaging,
microwave susceptors and modifiers,
temperature-sensitive packaging
Microbial control UV and surface-treated packaging materials

9. Moisture Control
- Moisture absorbent pads and trays with applications for meat and poultry
- Lowering of water activity to suppress microbial growth
- Systems consist of super-absorbent polymers located between two other
plastic layers
Commercial Examples:
Dri-Loc® Absorbent pads,
CRYOVAC®, Sealed Air Corporation
• Pads perforated with tiny one-way valves
• Juices absorbed from the bottom
• Prevents meat from drying
Fresh-R-Pax™ Absorbent pads,
Fresh-R-Pax™ Absorbent trays,
Maxwell Chase Technologies, LLC.

10. Moisture Control
Advantages:
Enhanced product appearance and freshness
– shelf life extension
Removes and retains spoilage bacteria
Reduces costly rewraps and product downgrades
Reduces product and packaging waste
Pads protect product display cases
– enhanced visual appeal to customers

11. Oxygen Scavengers
Elevated O2 levels in food packages may facilitate:
Microbial growth
Off-odour and off-flavour development
Colour changes
Nutritional losses
A significant reduction in product shelf-life
Traditional MAP or vacuum packaging may not facilitate complete removal of O2
=> Residual O2 may be removed using oxygen scavenging technology
Existing technology based on: iron powder oxidation, ascorbic acid oxidation,
photosensitive dye oxidation, enzymatic oxidation (e.g. glucose oxidase), unsaturated
fatty acids, rice extract or immobilised yeast on a solid substrate

12. Oxygen Scavengers
Majority of commerically available O2 scavengers based on the principle of iron
oxidation:
Fe → Fe2+ + 2e-
½ O2 + H2O + 2e- → 2OH-
Fe2+ + 2OH- → Fe(OH)2
Fe(OH)2 + ¼ O2 + ½ H2O → Fe(OH)3
Ageless® Sachet
Effective with a variety of packaging materials
Reduce and maintains O2 to < 0.01%
De-oxygenation time ~ 1 to 4 days
Available as labels, sachets, cards or films
(incorporation of scavenging agent into the packaging film) Ageless® Label
Mitsubishi Gas Chemical Co.

13. Oxygen Scavengers
Advantages:
- Significantly reduces oxygen levels in packs
- Reduces oxidation reactions (pigments, lipids)
- Reduces aerobic microbial growth
FreshPax® Sachets FreshPax® Labels
Multisorb Technologies Inc.
Disadvantages:
- Concerns regarding anaerobic pathogens
- Activation - moisture dependent
- Sachet leakage/consumption
Atco® Sachet
Applications in sliced cooked meats (e.g. hams)
Prevent discoloration in fresh beef
(Allen et al., 1996; Tewari et al., 2001)
Atco® Labels
Emco Packaging Systems.

14. Oxygen Scavengers
UV light activated films composed of an
O2 scavenger layer extruded into a multilayer film
Reduce headspace O2 from 1% to ppm
levels in 4-10 days ~ comparable with O2
scavenging sachets
Applications:
Dried or smoked meat products, processed and sliced meats
Commercial examples:
Cryovac® OS2000™ polymer based oxygen scavenging film
ZERO2TM developed by CSIRO and VisyPak Food Packaging

15. Carbon Dioxide Emitters and Scavengers
Function of CO2 to inhibit microbial growth and extend product shelf-life
Removal of O2 or dissolution of CO2 in the product creates a partial vacuum
which may cause collapse of flexible packaging
⇒ Dual action CO2 generators / O2 scavengers
CO2 emitting sachets or labels can also be used alone
Further research required - safety risks of CO2 in packaging systems
e.g. C. botulinum type B
Commercial examples:
Ageless® G FreshPax® M
Mitsubishi Gas Chemical Co. Multisorb Technologies Inc.
Based on either ferrous carbonate or a mixture of ascorbic acid and sodium bicarbonate

16. Carbon Dioxide Emitters and Scavengers
Verifrais™ package (SARL Codimer) extends shelf-life of fresh red meats
Standard tray with a false, perforated bottom containing sachet of sodium
bicarbonate/ascorbate
Juice dripping from the meat onto the sachet results in CO2 emission
⇒ Replacement of CO2 absorbed by the meat
⇒ Prevention of package collapse
CO2 absorbers (sachets) consisting of either calcium hydroxide and sodium
hydroxide or potassium hydroxide, calcium oxide and silica gel
⇒ Removal of CO2 during storage to prevent bursting of package
⇒ Applications in dehydrated poultry products and beef jerkey

17. Antimicrobial Packaging
Antimicrobial agents: acid anhydride, alcohol, bacteriocins, chelators, enzymes,
organic acids and polysaccharides
Antimicrobial agents - may be coated, incorporated, immobilised or surface-
modified onto package materials
Antimicrobial films classified into two types:
⇒ films containing an antimicrobial agent which migrates to the food surface
⇒ films effective without migration

18. Antimicrobial Packaging
Antimicrobial coatings
Nisin coated films – reduction of S. typhimurium on surface of fresh broiler skin
and drumsticks (Natrajan and Sheldon, 2000)
Alginate coatings containing organic acids reduced levels of L. monocytogenes, S.
typhimurium and E. coli 0157:H7 on beef carcasses (Siragusa and Dickson, 1993)
Incorporation of antimicrobial agents
Films containing acetic or propionic acid in a chitosan matrix with/without lauric
acid or cinnamaldehyde applied to bologna, cooked ham or pastrami (Ouattara et
al., 2000)
Grapefruit seed extract incorporated into multilayer polyethylene films reduced
aerobic and coliform bacteria in minced beef (Ha et al., 2001)

19. Antimicrobial Packaging
Immobilisation
Nisin-adsorbed bioactive inserts reduced L. innocua and S. aureus in hams
(Scannell et al., 2000)
Pack inserts
Sachets of oregano essential oil in combination with MAP extended the shelf-
life of fresh beef (Skandamis and Nychas, 2002)
Commercial examples:
AgION™ (concentrate) Nisaplin® (extract) Microgard™ (film) Zeomic™ (powder)
AgION Technologies LLC Integrated Ingredients Rhone-Poulenc Sinanen Zeomic
Few commercial successes – Ag-substituted zeolite incorporated into plastics in
Japan

20. Introduction to Intelligent Packaging
(Second Level Packaging)
Packaging systems which monitor the condition of packaged foods to give information
about the quality of the packaged food during transport and storage (Ahvenainen, 2003)
Intelligent packaging in some way senses properties of the food it encloses or the
environment in which it is kept and which is able to inform the manufacturer, retailer
and consumer of the state of these properties
Information extensive, though much of it is conceptual
Limited commercial application to date

21. Intelligent Packaging Applications
Tamper evidence/pack integrity
- breach of pack containment
Safety/quality indicators
- time-temperature indicators (TTIs)
- gas sensing devices
- microbial growth
- pathogen detection
Traceability/anti-theft devices
- radio frequency identification (RFID) labels/tags/chips
Product authenticity
- holographic images, logos
- hidden design print elements
- RFID

22. Indicators
Substances that indicate the presence, absence, or concentration of another substance
or the degree of reaction between two or more substances by means of a characteristic
change, especially with respect to colour
Integrity (leak) indicators
Visual O2 indicators: use in low O2 packs
Number of patents (redox dyes) – MAP mince steaks, mince pizzas
Disadvantages
High sensitivity to residual O2 in MAP
Reversibility - undesirable where O2 is consumed
during bacterial growth
Few commercial devices available
Ageless-Eye®, Vitalon®, Samso-Checker®

23. Freshness Indicators
Provide direct product quality information resulting from
microbial growth or chemical changes within a meat product
Potential indicator metabolites
Organic acids, ethanol, biogenic amines, CO2, H2S,
microbes
Disadvantages
Based in broad-spectrum colour changes
Target metabolites do not necessarily indicate poor quality
Toxin Alert – ToxinguardTM
Freshness indicator measures Pseudomonas sp.
Antibodies in polyethylene-based packaging
- can also detect pathogens

24. Time-Temperature Indicators (TTIs)
Small tag or label used to show time-temperature history to which
a perishable product has been exposed
Diffusion-based, enzymatic and polymer-based TTIs offer most potential
VITSAB®, Fresh-Check® and 3M Monitor® - effective indicators of meat quality
‘Do not use if
circle is pink’
CheckPoint® (Vitsab International, Sweden)
TTIs: Price estimates from €0.02 to €0.15

25. Radio Frequency Identification Tags (RFID)
Wireless data collection technology that uses electronic tags for storing data and identification
of people, animals or objects.
Tags affixed to assets (cattle, pallets, meat bins, packs) to transmit information to a reader
Tags - transponder and antenna with unique number or identifier
- non-contact, non-line-of-sight, can penetrate bio-matter including meat (~ 125 kHz)

26. Radio Frequency Identification Tags (RFID)
Tags
• passive: simple, cheap, short-range, powered by
energy from reader
• active: battery powered, more info (temp, RH, nutritional
info, cooking instructions etc), longer range
Applications to meat
• trial stage
• tracking of beef from Namibia to UK
• birth to beef: RFID/bar code tracking
• ‘iBoS’ transport crate for meat products
• Wal-Mart, Tesco, Target, Metro AG
Costs
• ~ €0.40 and €0.75 per tag (passive) ; ‘€0.07 in volumes of 106’
RFID on boxes of frozen meat
• to cost ~ €0.01 after 2007? (TrolleyponderTM)
• decrease in cost critical to implementation

27. Sensors
Devices used to detect, locate or quantify energy or matter, giving a signal for
the detection of a physical or chemical property to which the device responds
Most contain two functional units:
Receptor - physical or chemical information transformed into a form of energy
Transducer - device that transforms this energy into a useful analytical signal
R&D mainly in biomedical and environmental applications
Used to determine a primary measurable or a secondary physical, chemical or
biological variable – ‘the marker concept’
High development costs, exacting industry specifications and safety considerations have
limited commercial realisation although significant steps have been made
Need for traceability, guaranteed quality and safety is promoting development

28. Gas Sensors
Recent developments in optical oxygen sensors based on
fluorescence quenching
Non-invasive technique for gas analysis through translucent materials
Fluorescent or phosphorescent dye encapsulated in a polymer matrix
=> O2 penetrates dye-polymer coating and quenches luminescence (energy transferred to O2)
=> quantified against pre-determined calibration
Ruthenium, palladium(II)-, platinum-porphyrin and porphyrin-ketone complexes
show promise for intelligent packaging use
Relatively long emission lifetimes (~40-500 μs) best for
food packaging applications
Fabrication – dissolution of indicator dye and polymer support
in organic solvent followed by drying
Large scale, continuous production possible

29. Gas Sensors
Operating criteria for optical O2 sensors in intelligent packaging:
Working range: 0 to 100 kPa O2; detection limits 0.01- 0.1 kPa.
Temperature dependence: Effective from -20 to +70 °C
Response: < 10-3 s, ideal for rapid on-line screening
Stability: Effective time/temperature/light/migration stability
Toxicity: Single pack sensor ~ 1 mg, of which > 95% support matrix: non-hazardous
OxySense® - first commercially available fluorescence quenching sensor
• > 98% correlation with GC
• Stable to 150 °C without loss of sensitivity
• Rapid (< 5 s per measurement)
• Headspace and liquid measurements

30. Oxygen Sensors
Platinum-based O2 sensors as quality control instruments for meat products
Fitzgerald et al. (2001)
Effects of residual oxygen in anaerobic MAP chicken and beef
Smiddy et al. (2002a,b,c)
Use of O2 sensors for headspace analysis of commercial ham products
Papkovsky et al. (2002)
Use of O2 sensors printed directly onto packaged sous vide beef lasagne
O’Mahony et al. (2004)
Migration of active components of O2 sensors in food packaging applications
O’Riordan et al. (2005)
Current research - new sensing materials and detection systems

31. Vacuum packed beef with O2 sensing membrane
O2 sensing equipment

32. Bio-Sensors
Compact analytical devices that detect, record and transmit information pertaining
to biological reactions
• Bioreceptor specific to a target analyte (enzymes, antigens, microbes, hormones etc.)
• Transducer to convert biological signals to an electrical response (electrochemical, optical etc.)
Few commercially available systems but more widespread use predicted
Contaminating bacteria render
bar-code unreadable
SIRA Technologies Inc.
Food Sentinel SystemTM

33. Active and Intelligent Packaging – The Future
These packaging technologies anticipated to grow significantly over the next 10 years,
due principally to:
- Consumer demands for meat and other food products which are premium quality and which
provide adequate shelf-life, safety, convenience and information
- Reduction in packaging material costs as formats grow in popularity/sales volume, and as
newer and cheaper formats emerge through research and development
- Greater demands by retailing outlets for extended product shelf-life
- Concerns regarding product authenticity and bio-terrorism
- Growing efforts to reduce unnecessary product/package wastes

34. Acknowledgements
My sincerest thanks to:
Dr Sean Hogan
&
Dr Michael O’Grady
for their invaluable assistance and support
throughout this entire project
Thanks for your
attention