Transfer of water and active molecules at the interfaces ... -Voilley... · (as a reference phase) 5. ... ethyl acetate in water ethyl hexanoate in sucrose solution ... PROTEINS AT

EFW 6-8 april 2008 - Nurtingen

Transfer of water and active molecules at the interfaces in complex food systems :

theoretical and practical aspects

Pr A. Voilley, Pr F. Debeaufort, Dr A.M SeuvreENSBANA, Université de Bourgogne, Dijon France

1

EFW 6-8 april 2008 - NurtingenEFW 6-8 april 2008 - Nurtingen

I. Basic of mass transfer and some physico-chemicalproperties of volatiles

II. Case studies – Mass transfers at the interfacesII.I without change of the physical stateII.II with changes of the physical state

III. Conclusions and perspectives

2


I. Basic of mass transfer and some physico-chemicalproperties of volatiles

3


Interface

Fluid 1

Fluid 2

Transferdirection

∆x1

∆x2

C1

C2

Ci1Ci2

Concentration profile

C

xSolute B

x

Interface

Boundarylayer ∆x

Transferdirection

Concentration profile

C1

C2C

Solid

Solute B

J: compound flow (kg. s-1. m-2)M: compound mass (kg)t: time (s)A: surface (m2)D: compound diffusion coefficient (m2. s-1)C: compound concentration (kg. m-3)x: distance (m)k: compound transfer coefficient (m. s-1) = D / dx

dCkdxdCD

dtAdmJ ..

=−==

4

EFW 6-8 april 2008 - NurtingenFLAVOUR COMPOUND PROPERTIES

Flavour compound = volatile and odorous organic compound at atmospheric pressure

satiP

Compound insolution Solubility in water

wateriγPartition with airActivity coefficient

Hydrophobic constantlog P

Volatility

Pure compoundSaturated vapour pressure (Pa) - T boiling

Compound incomplex solution

liq*i

gaz*il/g

i CCk =Apparent partition coefficient

Partition with octanol(as a reference phase)

5


PHYSICOCHEMICAL CHARACTERISTICS OF AROMA COMPOUNDS

Aroma compounds

2.8

1.7

0.6

2.2

2.9

Log P calc**

0.051-144C8H16O2Ethyl hexanoate

0.612-116C6H12O2Ethyl butyrate

8.692-88C4H8O2Ethyl acetate

0.244.45.5130C6H16O2Isoamyl acetate

0.040.30.4142C9H18O2-Nonanone

calc*exp.

Solubility in water

(g/100ml)25°C

Saturatedvapour

pressure (mmHg) 25°C

MolecularweightFormula

* Calculated from Lee-Kesler model (1975)** Calculated from Rekker method (1977) 6


CARBOHYDRATE MASS CONCENTRATION EFFECT ON FLAVOUR COMPOUND DIFFUSIVITY (25°C)

Diffusivity (10-10m2.s-1)

Acetone

Diacetyl

n-Hexanol

Mass concentration (%) of glucose syrup DE 61.5

7


DIFFUSION COEFFICIENT OF FLAVOUR COMPOUNDS IN DIFFERENT MATRICES

Diffusivity (m2.s-1)

10-10 10-910-1110-1210-1310-14 … 10-5

Water4, 5, 7,11

• Aqueous solutions of proteins4, 5

or polysaccharides6, 7

• Oil4• Gels (pectin8, alginate9,

carrageenans10, 11)

Porous solids2, 3Edible films1

Plastic flims1

Gas (air)

1Quezada-Gallo (1999)2Souchon et al. (1996)3Takeuchi and Suzuki (1984)4Rogacheva et al. (1999)5Landy et al. (1995)6Voilley and Roques (1987)7Voilley and Bettenfeld (1985)8Rega et al. (2002)9Lian et al. (2004)10Gostan et al. (2004)11Rondeau-Mouro et al. (2004)

In the same matrix, diffusion coefficient of flavour compounds

of the same order 8

SOLUBILITY OF ETHYL ACETATE IN AQUEOUS SUCROSE SOLUTIONS


0

50

100

150

200

-10 -5 0 5 10 15 20 25

Temperature (°C)

Solubility (g/L)

water

57.5%

Solubility varies with the composition of the matrix and temperature 9


SOME EXPLANATIONS :

Maximal density of bulk water:

maximum hydrogenbonds water-water

Weaker water-water hydrogenbonds and water

clusters:

=> allowingaroma

dissolution

44Temperature (°C)

30% sucrose43.5% sucrose57.5% sucrose

Solubility of hexanol(g/L)

10


COMPARISON BETWEEN HYDROPHOBICITY AND SOLUBILITY OF AROMA COMPOUNDS (25°C)

Solubility in water (g.L-1)

2-undecanone

2-nonanone

2-octanoneIsoamyl acetate

2-heptanoneAcetophenone

cis-3-hexenol

2,5-dimethyl-pyrazine

-2

-1

0

1

2

3

4

5Log P

0.01 0.4 1.5 2.4 4.3 7.1 18 ∞

11


VAPOUR LIQUID PARTITION COEFFICIENTS

K x 103

0.5

1.5

2.5

Benzaldehyde Linaloolvegetable oil

waterwith salt (NaCl)

with 3% dairy protein

12


VOLATILITY OF AROMA COMPOUNDS IN A 57.5% SUCROSE SOLUTIONAS A FUNCTION OF TEMPERATURE

0.00

4.00

8.00

12.00

16.00

20.00

-15 -10 -5 0 5 10 15 20 25 30 35Temperature (°C)

Kmassethyl hexanoate in water

ethyl acetate in water

ethyl hexanoate in sucrose solution

ethyl acetate in sucrose solution

13


II. Case studies – Mass transfers at the interfaces

II.I without change of the physical state

14

EFW 6-8 april 2008 - NurtingenLIQUID-LIQUID MASS TRANSFER

THROUGH A LIPID LAYER – PROTEINS AT WATER/LIPID INTERFACEDiagram of the Rotative Diffusion Cell

Cylindrical rotating baffle

Outercompartment

Filter saturatedwith the lipid

Inner compartment witharoma compounds

Thermostattedwater

Protein at water /lipid interface

Lipid in filter pores15Flavour compound


TRANSFER IN THE ROTATIVE DIFFUSION CELL

OVERALL RESISTANCE TO THE MASS TRANSFER

16

PDL

k2

DZ2

k1R

0iaq α+

α+==

1/k: total resistance (m-1.s)Daq : solute diffusion coefficient (m2.s-1)Z : thickness of the stagnant layer (m)ki : permeability coefficient (m.s-1)α : porosity of the filter (0.8)L : thickness of the oil membrane (m)Do : solute diffusion coefficient in oil (m2.s-1)P : solute liquid-liquid partition coefficient

RESISTANCES

Diffusion in aqueous stagnant layer = Raq

Interfacial transfer = RI

Diffusion in oil = Roil

aqDZ2

PDL

0α

ik2α

WATER

OIL MEMBRANE

WATER

Levich model


RESISTANCE TO THE MASS TRANSFER OF THE AROMA COMPOUNDS

Ioil RRRaqk1 ++=

Levich equation

Raq, resistance to the diffusion in the aqueous phase;Roil , resistance to the diffusion in the lipidic phase; RI, resistance to the diffusion in the two limit aqueous layers

Aroma compound β-lactoglobulin (%, w/w) Raq (%) Roil (%) RI (%)benzaldehyde 0 89.2 5.9 4.9 benzaldehyde 3 78.3 4.8 16.9 2-nonanone 0 55.7 0.3 44.0

2-nonanone (pH 3) 3 38.9 0.6 60.5 2-nonanone (pH 9) 3 64.1 0.9 35.0

17


18

t.D2xerfc

21

CC

0

)t,x( =

x

0CC

x

0CC Without barrier With barrier

Homogeneous and same mediumin each cylinder

CONCENTRATION PROFILE METHODE FOR THE DIFFUSIVITY DETERMINATION WITH SOLID PHASES

At t=0

At t time

x

0CC Interface


WATER CONTENT PROFILE FOR A SPONGE CAKE IN CONTACT WITH A GEL AT 20°C

-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.520

30

40

50

60

70

80

Dis tance (cm)

Teneur en eau (g/100g m.h.)

J+1J+3J+7J+14

Gelatin gel Sponge cake

-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.520

30

40

50

60

70

80

Dis tance (cm)

Teneur en eau (g/100g m.h.)

J+1J+3J+7J+14

Gelatin gel Film Sponge cake

Wat

er c

onte

nt (g

/100

g w

.b.)

Wat

er c

onte

nt (g

/100

g w

.b.)

60% fat emulsified in iota-carrageenan film (100µm)

19

StrEFW 6-8 april 2008 - Nurtingen

INFLUENCE OF WATER ACTIVITY ON THE FLUORESCEIN DIFFUSIVITY IN CARRAGEENAN EDIBLE FILMS

0 0.2 0.4 0.6 0.8 10

0.4

0.8

1.2

1.6

aw

Fluorescein Diffusion Coefficient D (x10 -12 m2.s-1)

Change in structural propertiesof the carrageenan matrix

20


II. Case studies – Mass transfers at the interfaces

II.II with changes of the physical state

21


Liquid or Solid matrices Vapour phaseinterface

Simple systemSolubility in the matrix

Partition with air Volatility

Complex system

*/

*

gazg l ii liq or solid

i

CkC

=

Apparent partition coefficient

Partition between the different phases of the matrix

22

EFW 6-8 april 2008 - NurtingenVAPOUR/MATRIX MASS TRANSFER COEFFICIENT OF ETHYL

HEXANOATE IN DIFFERENT FOOD MATRICES

MATRIX

MASS TRANSFER COEFFICIENT OF

ETHYL HEXANOATE

(×107 m.s-1)

EXPERIMENTAL CONDITIONS

REFERENCE

Water 9.2

7.6

Dynamic cumulative headspace, 25°C

Static headspace, 25°C

Juteau et al.

(2004)

Oil in water emulsion (2% fat)

10 Dilution by a stream of

gas, 22°C Doyen et al.

(2000)

Iota-carrageenan gel 2 Static headspace, 25°C

Starch gel 6.9 Dynamic cumulative

headspace, 25°C

Juteau et al. (2004)

Dairy gel with 5% fat 9

Pectin gel 1.9 Static headspace, 10°C

Nongonierma

et al. (2005)

Great influence of the experimental conditions on the values23


Ethyl butanoate Pentan-2-one

Ethyl acetate Ethyl hexanoate

RATE OF RELEASE OF SOME AROMA COMPOUNDS INDIFFERENT MATRICES WITH SAME VISCOSITY(37°C°

water carbohydrate matrix emulsion complex matrix 24


MATRIX EFFECT ON VAPOUR / MATRIX TRANSFER COEFFICIENT

Dairy gel (D.G.) 0% fat

EAEB EH

EI

0 0.5 1 1.5 2 2.5 3

logP

0.0

0.5

1.0

1.5

2.0

2.5

Mas

s tr

ansf

erco

effic

ient

(1

06m

.s-1

)

EA

EI

EB

EH

D.G. 5% fatPectic gel (P.G.)

EHEAEBEI

EA: ethyl acetateEI: ethyl isobutanoateEB: ethyl butanoateEH: ethyl hexanoate

Interface vapour/matrix

25

D.G. 5% fat logP

P.G. Transfer P.G. << D.G.

Effect of the fat

Main effect of the pectic gel

D.G. 0% fat no différence


Aro

ma

C/

C0

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600 800Time (h)

3,0

3,2

3,4

3,6

3,8

4,0

4,2

pH

1,40

1,45

1,50

1,55

1,60

Wat

er c

onte

nt

(kg

HO

/kg

d.b

.)2

COUPLED MASS TRANSFERS : PROTON, WATER and FLAVOUR COMPOUNDS BETWEEN THE DAIRY MATRIX AND THE PECTIC GEL

• H3O+ and flavour compounds transfers require same time scale compared to water

26

EFW 6-8 april 2008 - NurtingenMECHANISM OF MOISTURE OR CONDENSABLE VAPOURS

TRANSFER THROUGH BARRIER LAYERS

Permeation of small molecules through thin layers (interfaces) implies a molecular diffusion due to a chemical potential differentialbetween the two sides of the layer

Inner compartmentp1 - µ1 - aw1 - RH1

C1

C2

Desorption-evaporation

Condensation-sorptionouter compartmentp2 - µ1 - aw2 - RH2

Diffusion

Mass transfer mechanism : a 3 steps process :

• sorption coupled or not to condensation• diffusion of the small molecule in a liquid state• desorption coupled or not to evaporation

P = D x S

27


RELATIONSHIP BETWEEN DIFFUSIVITY AND PERMEABILITY

E-acetate

E-isobutyrate

2-pentanone

E-butyrate2-heptanone

2-pentanone

2-nonanone2-octanone

2-heptanone

E-acetate

D-Limonene

E-hexanoate

E-butyrateE-isobutyrate

1

10

100

1000

10000

100000

0,1 1 10 100

Diffusivity (10-13 m²/s)

Perm

eabi

lity

(10-1

4 g/m

.s.P

a)Gluten MC

There is no apparent relationship between the diffusivityand permeability of aroma compounds through neithermethylcellulose nor wheat gluten films

28


EFFECT OF AROMA HYDROPHOBICITY ON THEIR TRANSFER THROUGH METHYLCELLULOSE FILMS

2-nonanone

2-pentanone

isobutyrate d'éthyleethyl acetate

Log P Hydrophobicity constant

0

5

10

15

20

25

30

35

40

45

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5

Perm

eabi

lity

(10-

11g.

m-1

.s-1

.Pa-

1 )

2-heptanone

ethyl butyrate

2-octanone

1 octen-3 ol

ethyl hexanoate

Aroma hydrophobicity seems to be a key factor of the barrier properties

29


COUPLED TRANSFER RATES OF BOTH MOISTURE (RH)AND AROMA (1octen-3-ol)

0

50

100

150

200

250

0 20 40 60 80 100Water vapour transfer rate (10-4 g.m-2.s-1)

1-oc

ten-

3-ol

tran

sfer

rate

(1

0-6g.

m-2

.s-1

)

Plasticization of the polymer network by moisture

30


Carrageenansupport side

Carrageenan+ 60% fatsupport side

Carrageenan+ 60% fatair side

0 30 60 90 sec

Swelling

WVPrelative = 2,5

Side effect

WVPrelative = 1

15

Absorption

WVPrelative = 2

Contact time :

WETTING BEHAVIOUR OF CARRAGEENAN FILMS RELATED TO COMPOSITION, FACE EXPOSED AND VATER VAPOUR

PERMEABILITY (WVP)

Both the composition (emulsifiers) and the surface structure strongly influence the water transfer in edible films

31


WATER DIFFUSION THROUGH THE FILM MEASURED BY FTIR-ATR

Multi-reflectionInfraredradiation

DetectorCrystal (ZnSe)

Film : 100 µm dp ~ 5µmLiquid water

Crystal

25003000350040000

0.5

1

1.5

2

-1

Abs

orba

nce

25003000350040000

0.5

1

1.5

2

Wave numbe r (cm-1)

Abs

orba

nce

t = 0 to 300 s(step: 15 s)

Wave numbe r (cm )

0 50 100 150 200 250 3000

0.2

0.4

0.6

0.8

1

time (s )

At/A

∞

0 50 100 150 200 250 3000

0.2

0.4

0.6

0.8

1

time (s )

At/A

∞ Air sidein contactto water

Dwater ~ 9 x10-11 m2.s-1

Carrageenan + 60% fat

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1

time (s )A

t/A∞

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1

time (s )A

t/A∞

∆t > 100 sSupport side

in contactto water

Non Fickian 32


EFFECT OF BOTH THE WATER ACTIVITY DIFFERENTIAL AND THE PHYSICAL STATE OF WATER

ON THE TRANSFER RATE OF CHOCOLATE BASED BARRIERS

0

200

400

600

800

1000

1200

1400

1600

Wat

er tr

ansf

erra

te

(10-5

g.m

-2.s

-1)

0.8-0.2 0.9-0.2 1.0-0.2

Water activity differential

liquid

vapour

33


LIQUID CONTACT VERSUS VAPOUR CONTACT :THE SCHROEDER PARADOX

For a same activity (or a same chemical potential) differential, the transfer rate through a dense membrane is always much greater when the diffusing substance

in contact to the membrane is liquid.

Aroma transfer through silicone membrane depends on the physicalstate of the aroma in contact with the membrane

From Valleries et al., 2006 34


III Conclusions and perspectives

35


kinetics = mass transfer coefficient, diffusivity…

Transfers =thermodynamics = solubility, partition coefficients,

affinity, interactions

Fick, Henry laws etc ….

An integrated approach of the mass transfers in foods :

How to take into account both :

structure/physical state and interfacial properties ???

=> from macroscopic to molecular scales36


37

PREDICTION OF MOISTURE TRANSFERS IN COMPOSITE FOODS :APPLICATION OF CACAO BASED COATINGS TO SUGAR WAFER

02468

1012141618

Tim

eof

sto

rage

(mon

th)

Target time

Aw critical = 0.45Aw critical = 0.45Aw critical = 0.35Aw critical = 0.35

Coating 1P = 2.7

Coating 2P = 1.1

Coating 1P = 2.7

Coating 2P = 1.1 10-11g.m . s .Pa-1 -1 -1

ExperimentalCalculated

Transfers play a role on quality preservation


RELATIONSHIPS BETWEEN TRANSFER RATE AND FLAVOUR PERCEPTION OF FRUITY STRAWBERRY ODOUR OF THE PECTIC GEL

y = 3,86x - 0,31R2 = 0,76

0

3

6

9

1,2 1,4 1,6 1,8Log10[ethyl esters]

Odo

urin

tens

ity

Transfers play a role on the sensory perception

38


Thanks to

Dr Cécile Dury-BrunDr Thomas KarbowiakDr Alice Nongonierma

Dr Marco Covarrubias-CervantesDr Valérie Morillon

39

Documents

Transfer of water and active molecules at the interfaces ... -Voilley... · (as a reference phase) 5. ... ethyl acetate in water ethyl hexanoate in sucrose solution ... PROTEINS AT