Packaging materials Course: Post-harvest technology and minimal processing of fruits and vegetables Telma Delgado & Maria de Fátima Poças Packaging Department Biotechnology College Portuguese Catholic University Lisboa, 3 5 December 2007
Agenda Product needs and packaging requirements for minimally processed F&V Types of packaging Packaging materials Active and intelligent packaging
Product needs Monitoring and controlling Temperature Respiration, ethylene production, water loss Respiration rate increases 2-3 times each 10ºC increase Handling conditions Mechanical damage acelerates senescence Concentration of gases in the product surroudings
Packaging system requirements Barrier properties Oxygen, Carbon dioxide Water vapour ß = PCO 2 /PO 2 Variation with temperature Package format and volume Integrity (seals efficiency) Optical properties (anti-fogging) Material safety and leg. compliance Mechanical resistance and handling
Barrier properties β C DC [ ] ( ) ar ar C + C C ( ) DC 1 β Ox Ox
Package format and volume C DC ( ) = ar R + DClW P A DC t C 1 exp t DC P DC A lv C Ox ( ) = ar R OxlW P A Ox t C 1 exp t Ox P Ox A lv
Types of packaging Pouch Tray with lid or inside a pouch Tray with lid Machines integrated or not
Types of packaging machines Vacuum chamber, for pouches Trays inside a pouch http://www.airproducts.co.uk/food/map/
Types of packaging machines Trays and lid Pre-formed FFS http://www.airproducts.co.uk/food/map/
Types of packaging machines MAP in bulk for fresh F&V
Packaging materials Permeability @ 10ºC mlµm/cm2dayatm PO 2 PCO 2 β PB LLDPE PVC Ceramic-filled LDPE EVA Ceramic-filled PS LDPE CPP OPP HDPE PET Nylon multilayer PVDC Silicon rubber Perforation (air) Microporous film 68.2 15.7 14.0 12.1 10.1 7.1 6.7 3.2 2.1 0.1 0.1 0.1 2.8E-3 680 1.5E+8 2.3E+6 603 61.1 85.3 53.8 60.0 38.4 22.3 9.2 6.4 0.6 0.4 0.4 2.8-2 4.3+3 1.2E+8 2.3E+6 8.8 3.9 6.1 4.4 5.9 5.4 3.3 2.8 3.1 4.7 3.4 3.5 10.2 6.4 0.8 1.0
Problems and developments Films with permeability and ß suitable New materials: perforated, microporous, etc. Permeability data @ temperature of use Time for equilibrium Injection of correct mixture Temperature variations through distribution chain and during storage Active and intelligent systems
Packaging materials Films with improved barrier properties E-VA high E content (6-18%) LDPE (Elvax, DuPont), S-B block copolymer films (K-Resin, Chevron Phillips Chemical) ULDPE (ethylene-octene) copolymer films (Attane series, Dow Chemical) Polyolefin plastomer octene copolymer films (Affinity series, Dow Chemical) OPP laminates (BP Amoco)
Packaging materials Laser microperforated film Permeability depends: Diameter and number of perforations (< 150 µm) Example: Amcor
Packaging materials Microporous films Films extrusion with mineral fillers CaCO 2, SiO 2 Permeability: amount of filler, particle size and film stretching degree Exemple: Fresh Hold (River Ranch, Inc.)
Active and intelligent systems Ethylene absorbers Antimicrobial materials Oxygen emissor/carbon diox. Absorber TTIs Breathable materials Volatiles indicators RFID labels
Ethylene absorbers Ethylene Control, Inc. Peak Fresh Ethylene Control, Inc. Bio Fresh TM Delta Trak
Antimicrobial agents Film Food Film Food Avery-Dennison's label Releases ClO 2
Emitter O 2 /Absorber CO 2 OxyFresh (EMCO Fresh Technologies Ltd)
TTI s Used by Monoprix since 90`s Fresh-Check in individual packages 400 own-brand products Carrefour since 2005 in on-line sells
TTI s Monitoring Q Visible response X X = f ( t) K = K dq = dt 0 E exp R kq Q 1 T 1 T 0 df dt ( x) = F df dt K ( X ) = K t TIo ( x) = TI K TI E exp R TI 1 T 1 T 0 Selection of TTI should consider the match between E Q and E TI
E Q and E TI match Product Cut carrot Mushrooms Strawberry Q Respiration rate Colour change Firmness Ea (KJ/mol) 79 63 39 TTI Mechanism Ea (KJ/mol) Monitor Mark Check point Diffusion Enzymatic 33-35 50-113 Fresh-Check Polymerization 84-100
TTI s Fresh-Check
Breathable materials Materials with permeability responding to changes in temperature Rate Respiration rate Permeability of BreatheWay membrane Permeability of a typical polymer Temperature
Breathable materials System BreatheWay TM
Volatiles indicators Indicador RipeSense (Jenkins Group)
RFID