institute for horticultural science institute for food...

1

1Institute for Horticultural Science

Institute for Horticultural Science

Institute for Food Technology


tray

tray

film

film

closed container

bundle

closed container

2



oPP-film, 26 µm PE-film, 20 µm

3


oPP-film, 26 µm PE-film, 20 µm


Modelling the Gas Atmosphere in MAP-Headspace as a Tool for Optimizing Fruit

and Vegetable Packages

F. Lippert,

4


The objective of the presented research is to develop a tool to simulate the dynamics of gas exchange processes within packages for fruit and vegetable

objective


• material & methods• model description• validation• future prospect• summary

outline

5


• measuring respiration– CO2- production (GC, heat flow -detector)– O2- consumption (paramagnetic)

• film transmission rates (flow through system)

• CA-storage (open system)

• packaging trials (defined flow-packs)

materials & methods


Konz

entra

tion

[%]

Typischer Verlauf der Konzentrationsänderungen von O2 und CO2- innerhalb von MA-Verpackungen

steady-state

model description

0

5

10

15

20

25

0 10 20 30 40

time after packaging [h]

O2

/ CO

2 -c

once

ntra

tion

[%]

carbon dioxideoxygen

6


respiration rates as a function of temperature

RCO2 = Ar * EXP

RCO2...CO2 -production [ml*kg-1*h-1] Ar.......Arrhenius constantEa......activation energy

[kJ * mol -1]R .......gas constant

[0.008314 kJ mol-1 K-1] T........temperature [K]

Ea

R* T

0

200

400

600

800

1000

1200

0 5 10 15 20 25 30temperature [°C]

resp

iratio

n [m

g C

O2/

h/kg

]

carrot

broccoli

asparagus

model description


0

5000

10000

15000

20000

0

25000

50000

75000

100000

Sauerstoff

Kohlendioxid

0

200

400

600

800

0 5 10 15 20 25temperature [°C]

O2-

trans

mis

sion

[ml*m

-2*T

ag-1

]tra

nsm

issi

on[m

mol

*m-2

*Tag

-1] CO

2-tra

nsm

issi

on [m

l*m-2

*Tag

-1]

water vapor

transmission rates of a 20µm LDPE-film for O2, CO2and water vapor (Moyls et al.,1998)

model descriptionoxygen

carbon dioxide

7


CO2

KmnO2

0

50

100

150

0 2 4 6 8 10 12 14 16 18 20

O%

5%

10%

0

10

20

30

40

50

0 2 4 6 8 10 12 14 16 18 20

O%

5%

10%

0

10

20

30

40

50

0 2 4 6 8 10 12 14 16 18 20

O%

5%

10%

O2-concentration [%]

O2-

cons

umpt

ion

[ml*k

g- 1*h

-1]

Brokkoli

Spargel

Chicoree

VO2 = VmO2 * O2

(KmO2 + O2)*

VO2........O2 -consumption [ml*kg-1*h-1] VmO2.....max. O2 –consumption [ml*kg-1*h-1]KmO2.....Michaelis-constant for

O2 -consumption [% O2]O2 ........O2 -concentrationCO2 ......CO2 -concentrationKmnO2....Michaelis-constant for CO2 - related

inhibition of O2 -consumption [% CO2]

O2-dependent respiration rates at different CO2- concentrations (0, 5, 10 %) Peppelenbos, 1996

model description


•Arrhenius constant, Arp•activation energy Erp•Michaelis-Menten constant, KmO2•Michaelis-Menten constant,KmCO2•respiratory coefficient, RQ•weight, E•Status of energy•biological age

model inputproduce specifity

•O2-transmission rate, Tro•CO2-transmission rate, Trc•film thickness, FD•volume, V•surface, O•Arrhenius constant, Arf•activation energy, Eaf

•temperature (fluctuation)•atmospheric condition

exogenous variables

film

O2

O2

CO2

CO2diffusio

n

resp

iratio

n

diffusion

diffusion

package specifity

8


E2

temperaturefluctuation

air_O2

internalatmosphere (O2)

fresh produce

Diffusion (O2)

O2-consumption

temperature drivenrespiration(Arrhenius)

temperature

E1

temperaturefluctuation

Diffusion(CO2)

model design

packaging

internalatmosphere

(CO2)

CO2-production

Michaelis-Mentenkinetic

air_CO2


Folie: LDPE, 20 µ

0

5

10

15

20

25

0 20 40 60 80 100 120 140 160Stunden

CO2 -

/ O2 -K

onze

ntrati

on [%

]

broccoli in LDPE (20µm), weight 80 g

validation

O2-concentration

CO2-concentration

hours

CO

2-/O

2co

ncen

tratio

n[%

]

9


broccoli in oPP (26 µm), weight 80 g

validation

Folie: oPP, 26 µ

0

5

10

15

20

25

0 20 40 60 80 100 120 140 160Stunden

CO2 -

/ O

2 -Kon

zent

ratio

n [%

]

O2-concentration

CO2-concentration

hours

CO

2-/O

2co

ncen

tratio

n[%

]

hours


cherries in LDPE (20 µm), weight 100 g

validation

Folie: LDPE, 20 µ

0

5

10

15

20

25

0 20 40 60 80 100 120 140 160Stunden

CO2 /

O2-K

onze

ntrati

on [%

]C

O2-

/O2

conc

entra

tion

[%]

hourshours

O2-concentration

CO2-concentration

10


temperate fluctuation ( 0 °C to 20 °C after 60 h)

future prospects

0.00 50.00 100.00 150.000.00

5.00

10.00

15.00

20.00

25.00

Packung_CO2Packung_O2


active packaging (25 %CO2, 21 % O2)

0.00 50.00 100.00 150.000.00

5.00

10.00

15.00

20.00

25.00


future prospects

11


summary

film properties

To develop and to assess specific packaging for fruits and vegetable based on suitable produce-film-combinations thefollowing input defaults have to be made

produce properties

temperature

other parameters

The first results of modelling the dynamics of internal CO2 – and O2 – concentrations within flow packs was presented. It could beshown that the interrelation between all relevant parameters on a theoretical base is possible.


Max Planck:

Die Naturwissenschaft braucht der Mensch zum Erkennen, die Religionbraucht er zum Handeln, weil wir mit unseren Willensentscheidungen nicht warten können, bis die Erkenntnisse vollständig und wir allwissend geworden sind.

Pack and PrayArt Cameron:

12


Sortenabhängige Respirationsraten bei Feldsalat (bei 2 °C)

0

5

10

15

20

25

30

Trophy Juvert Vit Eurion Jade Gala Fiesta Rodion Favor Dante Cirilla

O2-V

erbr

auch

[ml /k

g/h)

Validierung


0

100

200

300

400

500

600

0 5 10 15 20 25 30 35

Temperatur [°C]

Res

pira

tion

Verb

rauc

h/Pr

oduk

tion

[ml/k

g/h]

Messung O2 Messung CO2O2_1 CO2_1

O2 CO2

Ar: 5,029 * 1013 1,504 * 1010

Ea: 63,535 44,512

Brokkoli, Arrhenius-Diagramm

Lite

ratu

rwer

te

Validierung

13


Modellierung von Feldsalat in LDPE, Einwaage 50 g

Ausblick

0.00 50.00 100.00 150.000.00

5.00

10.00

15.00

20.00

25.00


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