Active and Intelligent Packaging –

Solutions and Current Developments

European Coatings

Conference - Packaging and can coatings Corinna Keupp, Sven Sängerlaub

Structure

History of packaging

Problem definition

Active Systems

Intelligent Systems

Conclusion

Future perspectives

History of Packaging

Convenience Enclosure Protection Communication

Intelligent Packaging Active Packaging

• Time-Temperature Indicators • Food Freshness Indicators • Humidity Indicators • Oxygen Indicators

• Sterilization Indicators

• Oxygen Scavenger • Antimicrobial Materials • Humidity Absorber • Off-flavour Absorber

• Carbon dioxide Absorber/Release

• Ethylene Absorber

Problem definition

Increasing demands of consumers (more freshness, more safety)

Lack of confidence

Increasing globalisation

Throwaway society

Shelf life

Active systems

Oxygen scavenger

Gallic acid based oxygen scavenger

base

Ref.: Tulyathan V. et al.: Oxygen Uptake by Gallic Acid as a Model of Similar Reactions in Wines, J. Agric. Food Chem.,

37, 1989, 844-849

O2-absorption of gallic acid

Gallic acid based oxygen scavenger

gallic acid

two component

polyurethane adhesives

solvent

Adhesive is incompatible with base – coating on basic substrate.

Adhesive gains an additional oxygen absorbing functionality.

coating on a basic

substrate

Gallic acid oxygen scavenger

0

50

100

150

0 2 4 6 8 10 12 14 16

t / d

O2-a

bso

rpti

on

/ m

ass

s

caven

ger

[cm

3 O

2/g

Scav.]

0

100

200

300

O2 -a

bso

rptio

n / a

rea

[cm³ O

2 / m²

film]

PE / EVOH / PE(CaO) / scavenging layer (adhesive) / PEfoamedPE/EVOH/PE( 30 % w/w CaO Ø 2 µm)/ PU with 15 % w/w gallic acid 5 µm/PEfoamed 42 µm

Micrograph of gallic acid

Active systems

Antimicrobial materials

Antimicrobial films with sorbic acid/benzoic acid

antimicrobials

active lacquer

coating

base layer

microorganism

Ref.: Hauser,C., Rodler, N.(2009). Antimikrobiell aktive Folien. LVT Lebensmittelindustrie (5-6), 28-30

Release-System:

migration of antimicrobial substances

direct food contact needed surface protection of foods

sensitive to deterioration

On surface – often start of microbial growth.

Antimicrobial substance: highest efficacy on surface.

Antimicrobial films with sorbic acid/benzoic acid

Coating and laminating pilot plant at IVV

base-film

lacquering

drying-zone

active film

schematic demonstration of the lacquering process

Ref.: Hauser,C., Fraunhofer IVV

Antimicrobial efficacy of benzoic acid

Ref.: Hauser,C., Fraunhofer IVV

Antimicrobial efficacy - pork

1,0E+00

1,0E+01

1,0E+02

1,0E+03

1,0E+04

1,0E+05

1,0E+06

0 2 4 6 8 10

cfu

/meat

storage [d]

development of E. coli

reference active film

sterile cutting of 5 x 5 cm pieces

inoculation: 1.3 x 10³ cfu/piece with E. coli

vacuum packaging in active film and uncoated film

Ref.: Hauser,C., Fraunhofer IVV

Intelligent Systems

Humidity Indicators

Idea: deliquescent bases

relative humidity

wa

ter

con

ten

t

not active active

Some bases form liquids when certain relative humidity is

exceeded. Selection of base: setting of colour change.

Humidity Indicator with Al and hygriscopic substances

outside

inside

Polymer [20-100 µm]

Color + hygroscopic substance [~1 µm] Aluminium [30-80 nm]

Polymer [20-100 µm]

Activation: Al reacts with humidity inside the

packaging Color becomes visible

Humidity Indicator with Al and hygroscopic substances 1 part Na2CO3 + 1 part NaI; 50 % RH, 1 day, 23 °C

1 part Na2CO3 + 1 part NaI; 30 % RH, 1 day, 23 °C

Deliquescence

points (% RH):

NaI 40

Na2CO3 92

Possible application techniques

Print base on

aluminium layer

Print base on film and

laminate film on

aluminium layer

mix aluminium flakes

and base in printable

carrier (metallic dyes)

base

aluminium

polymer

polymer

base

aluminium

polymer

carrier

base

aluminium

polymer

Intelligent Systems

Food Freshness Indicators

FreshnessGuard

FreshnessGuard detects

sulphur containing compounds,

mainly hydrogen sulphide

a nano-scale layer of silver is

printed on the inside of the

package in shape of a cross

the reaction of sulphides with

silver causes a color change of

the cross from opaque light

brown to transparent

Ref.: DE 11 2004 000 841 T5

Microbial Sensor

It`s fresh is based on a metal

co-ordinated complex which

undergoes a ligand exchange

with sulphur or nitrogen

compounds

The color changes from yellow

to pink by releasing the ligand

Still under development

Ref.: www.foodfreshness.com and US 7,153,532 B1

Conclusion

Active and Intelligent Systems can provide several benefits to the

quality and safety of foods

Some Active and Intelligent Systems can be applied on the

packaging by printing methods

The application is ruled by the Framework regulation (EC 450/2009)

They can be used as marketing tools

Future perspectives

Active packaging is an evolving technology

There is a need for further research, especially for Intelligent

Systems

Retailer and consumers need to be trained/informed about the

advantages.

Contact details

Corinna Keupp

Chair of Food Packaging Technology

keupp@wzw.tum.de

Sven Sängerlaub

Fraunhofer IVV

sven.saengerlaub@fraunhofer.ivv.de