Packaging Design for Chilled Product

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Eleanore Haynes
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1 Packaging Design for Chilled Product 4th Int. Workshop»Cold Chain Management«27./28. September 21 in Bonn Kajetan Müller, Doris Gibis

2 Content Requirements of chilled products Adjustment of the gas transmission by permeation Adjustment of the gas transmission by perforation Active packaging concept

3 oxygen permeability [cm³(stp/(m² d bar)] Sauerstoffdurchlässigkeit bei 23 C / cm³(stp)/ (m² d bar) Requirements of chilled products und pf bei ormiert Dicke von 2gkeit ,1,1 PTFE (LCP) PE-HD BOPP PCTFE PVDC Dairy products PEN EVOH, 38% PE-LDPUR- Elastomer PP PVC-P COC POM Sausage PVC-U PET PAN EVOH, 44% PS PC PLA EVOH, 32% EVOH, 27% PA 6 fruits PMMA meat/ MAP Cellulose,1, Wasserdampfdurchlässigkeit Water vapour permeability / g / m 2 bei 23 C, 85 % r. F. / water vapour d at 23 C, 85% r.h. g/ (m² permeability d bar) [g/(m² d)] Focus of this presentation

4 Parameters affecting the quality of fruits and vegetables Initial quality (postharvest quality, microbial status, vitamin content ) preconditioning (washing, slicing, drying) Packaging process Important aspects, But not in the focus of this presentation Storage conditions (temperature, humidity) Gas composition (mainly H 2 O, CO 2 and O 2 ) Permeability of the packaging

5 Influence of temperature on the respiration rate Respiration rate in mg CO2/(kg h) Zucchini Pumpkin Tomato Cucumber Kiwi Banana (peelede) Strawbery Peach Grape Melon For many fresh products: Q 1 = 2 5 (The reaction rate increases by a factor of 2 to 5, when increasing the temperature by C) 5 T in C Q 1 Watada, A. E. / Postharvest Biology and Technology 9 (1996)

6 Respiration Gas exchange and release of water by respiration C 6 H 12 O O 2 6 CO H 2 O 19 mg kgh 2 mg kgh 28 mg kgh 11 mg kgh e.g. Zucchini at 4 C Exchange should be possible for a) Oxygen b) Carbon dioxide c) Water vapour H 2 O H 2 O O 2 CO 2 O 2 O 2 CO 2 CO 2 H 2 O H 2 O

7 Relative Reaction rate Respiration depending on oxygen concentration Example: salad Michaelis-Menten kinetic of the respiration Anaerobic metabolism 1 % Respiration rate Reduction of respiration rate by Reduction of Oxygen concentration Damage by anaerobic metabolism Oxygen concentration [%]

8 Carbon dioxide concentration [%] Brocc oli Suggested gas composition Salad sliced Artichoke Kale Radish celery Parsley Spinach Salad, whole Asparagus Oxygen concentration [%] Raw data from: Saltveit, M. E.: Is it possible to find an optimal controlled atmosphere? Postharvest Biology and Technology 27 (23) 3-13

9 Humidity and temperature changes transhipping: car to refrigerator Reduction of temperature 2 to 5 C in one hour Consequence: condensation 1 g water per kg air for 1 cm³ head space 1 mg package h

10 Mass transport through the package Gas exchange by 1. permeation through plastic 2. diffusion through pores O 2 CO 2 O 2 CO2 O 2 CO 2 H 2 O O 2 H 2 O CO 2

11 { Lösung Mass transport through the package 1. permeation Solution diffusion model P = DS Driving force: partial pressure difference Adsorption and absorption of gas molecules Diffusion through the polymer Desorption on the other side p 1 p d Diffusion Permeation Table: Influence of temperature on permeation p 2 Gas permeation through a polymer A p1 p2 Q gas P l Arrhenius approach: ED H S P D S P exp R T with P D S and E E H P D S

Sauerstoffdurchlässigkeit Oxygen transmission rate bei 23 C / Cm³(STP)/(m² cm³(stp)/(m² d d bar) bar) Mass transport through the package H 2 O permeation through plastic 1.

12 Sauerstoffdurchlässigkeit Oxygen transmission rate bei 23 C / Cm³(STP)/(m² cm³(stp)/(m² d d bar) bar) Mass transport through the package H 2 O permeation through plastic 1. H 2 O production (Zucchini) 4 C: 4. Selection of packaging material Sauerstoff und Wasserdampf bei 23 C und normiert auf 1 µm Dicke von 2Durchlässigkeit ,1,1 PTFE (LCP) PE-HD BOPP PCTFE PVDC PEN EVOH, 38% PE-LDPUR- Elastomer PP PVC-P COC POM PVC-U PET PAN EVOH, 44% PS PC PLA EVOH, 32% EVOH, 27% PA 6 PMMA Cellulose,1, Wasserdampfdurchlässigkeit Water vapour permeability / g / m 2 bei 23 C, 85 % r. F. / Water vapour transmission d 23 C, 85% r.h. g/(m² d bar) rate at 23 C/85 %r. h. g/(m² d) mg Rough estimation: kg h r.h.= 1 %-93 %=7 % Depending on Thickness of the lid film (corresponds to.23mol/m³) zucchini = 1 kg lid film =.5 m² 3. Calculated permeability (converted to 23 C und r.h = 85 % or corresponds to.971 mol/m³) g 223 m² d

13 Oxygen transmission rate Sauerstoffdurchlässigkeit bei 23 C / cm³(stp)/(m² Cm³(STP)/(m² d bar) d bar) Mass transport through the package O 2 permeation through plastic 1. O 2 consumption (Zucchini) 4 C: 4. Selection of packaging material mg 2 2. Rough estimation: kgh p O2 =,2 bar or 8.8 mol/m³ Permeation: target area zucchini = 1 kg lid film =.5 m² von 2Durchlässigkeit Sauerstoff und Wasserdampf bei 23 C und normiert auf 1 µm Dicke ,1 (LCP),1 PTFE PE-LDPUR- PE-HD Elastomer PP PVC-P BOPP PCTFE COC POM PVC-U PET PAN PEN PVDC EVOH, 44% EVOH, 38% EVOH, 32% EVOH, 27% PS PC PLA PMMA PA 6 Cellulose,1, Wasserdampfdurchlässigkeit Water vapour permeability / g / m 2 bei 23 C, 85 % r. F. / Water vapour transmission d 23 C, 85% r.h. g/(m² d bar) rate at 23 C/85 %r. h. g/(m² d) 3. Calculated oxygen permeability 1 5 cm³( STP) m² d bar at 23 C

14 Mass transport through the package 2. Pore diffusion Pore diffusion Driving force: pressure or partial pressure difference Gas diffusion through a pore Q gas D gas A h c o, gas L h c i, gas Note: The effective length of perforation is the sum of film thickness l and the pore radius: L h = l + r Table: Diffusion coefficients (D) for a gas in air at ambient pressure

15 Mass transport through the package O 2 -Diffusion through pores 1. Oxygen consumption (Zucchini): 4. calculated pore number e.g.: 51 pores with (5 µm) mg 2 2. Rough estimation: kgh p O2 = 2 mbar zucchini = 1 kg lid film = 5 µm Q gas D 3. Calculated diffusion area.1 mm² gas A h c o, gas L h c i, gas

16 Mass transport through the package H 2 O Diffusion through pores 1. H 2 O production (Zucchini) 4 C: 11 mg kgh 2. Rough estimation: p H2O =.6 mbar zucchini = 1 kg lid film = 5 µm Q gas D gas A h c o, gas L h c i, gas 4. calculation pore number e.g.: 17 pores with (5 µm) 3. Calculated Diffusion area 33.8 mm²

17 gas concentration in % Speciality in packaging fresh products Comparison of the gas composition with permeation and pore diffusion time in days permeation O2 permeation CO2 diffusion through perforation O2 diffusion through perforation CO2 Permeation: P CO2 /P O2 =5 e.g. 2 µm PE-LD O 2 cm³ :1 m² d bar cm³ CO2 :5 m² d bar Perforation: P CO2 /P O2 =.8 O 2 CO 2 cm³ :1 m² d bar : cm³ 8 m² d bar

18 gas concentration in % Carbon dioxide concentration [%] Broccoli Speciality in packaging fresh products target-performance comparison of gas composition 25 Only pore diffusion: P CO2 /P O2 =,8 and RQ= permeation O2 permeation CO2 diffusion through perforation O2 diffusion through perforation CO Salad sliced time in days Permeation: P CO2 /P O2 =3 and RQ=1 Permeation: P CO2 /P O2 =5 and RQ=1 Permeation: P CO2 /P O2 =1 and RQ= Asparagus Parsley Spinach Artichoke Kale Radish celery Salad, w hole Oxygen concentration [%]

19 { Lösung Respirationsrate in mg CO2/(kg h) Speciality in packaging fresh products Influence of temperature: Respiration vs. free diffusion Respiration Permeation free diffusion 16 p 1 p d p Zuchini Gurken Kürbis Tomaten Kiwi geschälte Banane Q 1 = 2 5 Erdbeeren Weintrauben Pfirsich Honigmelone T in C Diffusion Permeation For most plastics: Gases: Q 1 = H 2 O: Q 1 = 2 3 Q 1 = 1.6 temperature range to 2 C

20 Conclusions Different chilled products need different packaging solutions Focusing on fruits and vegetables High but defined gas and water vapour permeation needed O 2 and CO 2 composition can be adjusted by combination of permeation and diffusion through perforation Adjustment of the right humidity in headspace is very difficult Active Packaging is an option for chilled products Examples are Oxygen scavenger for oxygen sensitive products Humidity Regulating Systems for fruits and vegetables

21 Speciality in packaging fresh products Targeted humidity control Humidity control by packaging material r. F. / % Targeted values for the rel. humidity Rel. humidity Gas / % Singh, P.; Saengerlaub, S.; Stramm, C. Langowski, H.C.: Humidity Regulating Packages Containing Sodium Chloride as Active Substance for Packaging of Fresh Raw Agaricus Mushrooms. 4th International Workshop "Cold Chain Management", 27th and 28th of September 21 in Bonn, Germany H 2 O H 2 O O 2 O 2 CO 2 O 2 O 2 CO 2 CO 2 H 2 O H 2 O CO 2 hours

STORAGE STUDIES ON KNOLKHOL BULBS USING DIFFUSION CHANNEL TECHNOLOGY

I.J.S.N., VOL.7 (2) 2: 52-5 ISSN 222 1 STORAGE STUDIES ON KNOLKHOL BULBS USING DIFFUSION CHANNEL TECHNOLOGY Shilpa, K., Hanumantharaju, K.N., Arunkumar, H.S., Ramya, H.N. & Lakshmi R. Dept. Of Agricultural