iaal d. bounie, e. van hecke : high moisture extrusion - sydney, dec. 2 nd 97 high moisture...
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iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
High moisture extrusion : optimisation of texturisation
through control of rheologicaland textural parameters
D. Bounie, E. Van HeckeUSTL (Université des Sciences et Technologies de Lille)
IAAL (Institut Agricole et Alimentaire)Bâtiment C6
59655 Villeneuve d’Ascq Cedex - FranceTel : +33 (0)3 20.43.49.21, Fax : +33 (0)3 20.43.44.86E-Mail : Bounie@univ-lille1.fr, vanhecke@univ-lille1.fr
Smart Extrusion Workshop, Sydney,2 december 1997
(p1)
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
PLAN
(p2)
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
PLAN
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
Wet extrusionvs. dry extrusion
(Roussel, 1996)
HIGH MOISTURE EXTRUSION : APPLICATIONS
(p3a)
0 %
20 %
40 %
60 %
80 %
Moisturecontent %
Confectionery
Dry petfoods
TVPPetfood-moist
Pasta
Snacks - Flat breads
Breakfast cereals
Cheese analogs Enzyme reactors
Fruits and vegetables
Wet extrusion : usual raw materials(Roussel, 1996)
Animal raw materials red and white meat minces meat trimmings fish meats (surimi) filleting co-products minced from shell fish or cephalopoda egg or milk proteins
Vegetable raw materials protein-rich meals protein concentrates or isolates (soya, wheat, peas, brans,...) after adequate rehydratation
APPLICATIONS (Cheftel and al., 1992)
Sterilization preparation of sterile vegetables purées, meat-vegetables mixes
Chemical reaction (enzymic or acid hydrolysis) starch or proteins modification for preparation of glucose syrups,
fermentation substrates, flavor preparationsTexturization Gelation/fibration
gelation and fiber formation using vegetable proteins (soya, gluten) restructuration of mince, surimi, mechnically deboned meats (with
binders) texturization and fiber formation with fish muscle proteins
Emulsification/gelation : « microcoagulation » of dairy proteins processed cheeses cheese analogs fat substitutes casein coagulation
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97 (p3b)
MACRO AND MICRO STRUCTURES OF FIBROUS EXTRUDED PRODUCTS
A commercial extruded crab analogfrom Nippon Suisan(Cheftel and al, 1992)
Scanning electron micrographsof an extruded
surimi/soya concentrate mix(Thiebaud,1995)
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
TYPICAL EXTRUSION LINEFOR PRODUCT FIBRATION
(p3c)
Feeding device
Twin screw extruder with accurate temperature control
Gear pump
Extra long cooling die (Nippon Suisan patent)
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
PLAN
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
TEXTURIZATION : MELTING + FIBRATION
(p4)
Flow in extruder and cooled die
Metering zone Transition zone Die
Structure formation as a result of phase separation in biopolymer mixtures followed by subsequent orientation in flow
through die(Tolstoguzov, 1986 ; Mitchell et al., 1994)
Biopolymer phases separate into different domains
in extruder
Domains orientate as a result of flow through die
Products sets to fibrous structure on cooling
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
PLAN
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
COOLING DIES FOR TEXTURATION
Rectangular die
(p5)
Circular die
Annular die
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
FLOW PATTERN IN EXTRUDER AND DIE(Bhattacharya and Padmanabhan, 1992)
(p6)
Metering zone Entranceregion
Viscometric flowregion
Exitregion
Intermediaryregion
(relaxation)
P
die axis
Shear flow
Pentry
Extensional flow Shear flow
Pexit
Pshear flow
Ptotal = Pentry + pshear flow + Pexit
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
FLOW PROFILES THROUGH DIESEffect of cooling
(p7)
Flow through insulated die
Flow through supercooled die
Liquid Liquid / solid Solid
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
EFFECT OF OPERATING CONDITIONS ON FLOW,TROUBLESHOOTING
(p8)
Effect of implementing a non-newtonian fluid
m = 1m < 1
m << 1
Effect of viscosity
Increase of viscosity
Decrease of viscosity :
. increase of water content. increase of temperature
Troubleshooting
«Shark-skin» : periodic rupture of fluid bed (no slip at die wall)
«Two-phases wavy flow» : insufficient cooling rate (die too short or too thick) ; inner layers of flow are still melted at die outlet
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
PLAN
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
STRESS TENSOR
(p9)
2,1
1,3
3,2
3,1
1,22,3
2
3
1
Shear stress (if no rotation, i.e. no torque)
3,1 = 1,3
3,2 = 2,3 2,1 = 1,2
N1 = 1,1 - 2,2 (first normal stress difference) = e = k ( : elongational strain rate)
N2 = 2,2 - 3,3 (second normal stress difference)
N2 < 0, N2 << N1
2 .
Normal stress
1,1
2,2
3,3
2,2
3,3
1,1
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
SHEAR VISCOSITYT
(p10)
F
S
dl
x
dxv
v = dl
dtshear velocity (m.s-1)
T = F
Sshear stress (N.m-2 = Pa)
= dv
dxshear rate (s-1).
Ts = shear viscosity (Pa.s)
.
.
T
s
Bingham plastic
Newtonian
Pseudoplastic(shear thinning)
Dilatent(shear thickening)
T,o
Yieldstress
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
VISCOSITY : LAWS OF BEHAVIOUR
(p11)
constantNewtonian
Power law (Ostwald’s law)(K : index of consistency,m :flow behaviour index
m-1.Non Newtonian
m-1) e -T.
Effect oftemperature T
(Harper and al., 1971)
m-1 ) e -MC.
Effect ofmoisture content MC(Harper and al., 1971)
m-1)e dt - k e
-ERTa(t)
.
Effect of chemical reaction (E, R)(Remsen and Clark, 1978)
m-1 ) e -W.
Effect of thermo-mechanical history W (SME)
(Della Valle and Vergnes, 1994)
= Ko e ( - a MC - b W)
m’-1
with : m’ = c1 T + c2 MC + c3 MC.T
.ERTa
Example : corn starch at low MC(Della Valle and Vergnes, 1994)
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
IN-LINE MEASUREMENT OF VISCOSITY
(p12)
Qv
P
L
L
P
(Mac Master and al., 1987)
Shear stress at wallw
Apparentshear rate at wall
w, a
.
Realshear rate at wall
w, r
.Viscosity
RR P 2 L
4 Qv
R3
4 Qv
R3
3m + 1
4m
w
w, r
.
h P 1 2 L 1 +
hW
6 Qv
W h2
6 Qv
W h2
2m + 1
3mh
Ww
w, r
.
Log K
Log w
Log w, a
.
for different Qv
m
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
IN-LINE RHEOMETERSWITH CONTROLLED FEEDRATE
(p13)
By pass or side stream rheometers (Goettfoert system for plastics)
Gear pump
Rheometer
Derivation
« Rheopac » slit die rheometer (Vergnes et al., 1990 and 1993)
Piston keys
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
DISPLAY OF ELASTICITY :Weissenberg effect, Barus effect
(p14)
Weissenberg effect
increase with increasing
.
N
T
die extrudate
Barus effect : swelling at die outlet
T
N)N
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
IN-LINE MEASUREMENT OF ELASTICITY :EXIT PRESSURE METHOD(Padmanabhan and Bhattacharya, 1991)
(p15)
P
L
Pentrance
related to extensional viscosity
Pexit
proportional to elasticity
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
Qv
IN-LINE MEASUREMENT OF ELASTICITYHOLE PRESSURE METHOD
( Baird, 1976 ; Padmanabhan and Bhattacharya, 1992 ; Bhattacharya M. and Padmanabhan M., 1992, Malkus and al., 1992 ; Bouvier and Gelus,
1994)N
(p16)
P1 P2 P3
flush-mounted transducers
P
P1
P2
P3
P1,3 (shear viscosity)
L
P4
transducer at the bottom of the hole
P4
phole (elasticity)
N1 = 1,1 - 2,2 = e
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
DYNAMIC DETERMINATIONOF VISCOELASTICITY (1)
(Ross-Murphy, 1988)
(p17)
Force transducerAccelerometer
Imposed oscillatory
strain = f(t)
Measured stress = f(t)
Viscous fluid
Strain
(t)cost
t
Stress
(t)cost
2
Elastic fluid
Stress
Strain
t
Viscoelastic fluid
Stress
t
2
Strain
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
DYNAMIC DETERMINATIONOF VISCOELASTICITY (2)
(p18)
log scale
Viscosity
Ideal viscous liquid
Newton’s law
Loss modulus
.
G’’ = sin 0
0
Temperature
G’’
Elasticity
Ideal elastic solid
Hooke’s law
Storage modulus
G’ = cos 0
0
G’
Viscoelasticity
Viscoelastic fluid
G’’G’ = tg
Transition
or tg
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
ELONGATIONAL VISCOSITY
s
e
Newtonianfluid
Non-newtonianfluid
(Troutonmodulus)
Type of extensional flow
(p19)
Uniaxial extension
ex : spinning of fibers
3 >> 3
Planar extension
ex : foil stretching, central disk injection
4 >> 4
Biaxial extension
ex : blowing extrusion, plug extrusion
6 >> 6
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
ELONGATIONAL vs. SHEAR VISCOSITY
(p20)
Newtonianfluid
s
.
Non-newtonianfluid
s
.
e
e
s
e
constante
[= f(.s
e
= constante
In-line determination of extensional viscosity :Entrance pressure drop method(White and al., 1987 ; Bhattacharya and al., 1994)
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
PLAN
High moisture extrusion
Usual extrusion conditions (50 - 80 % water, 15 - 30 % proteins, fats <8 %,
> 130 °C) and consequences (reduction of : shear, viscous dissipation of
energy and expansion at die outlet, especially with long cooling dies)
Raw materials Main applications Typical extrusion line
• specific feeding device• special screw profiles (+ break plates)• long cooling-dies• temperature control
Fundamentals of high moisture texturization during extrusion-cooking
Main steps • protein melting (plasticising) : within the extruder• material texturization (fibration) : along the die
Flow in extruder and die during texturization Control of texturization through control of rheological behaviour
• (shear) viscosity• elasticity• visoelasticity• elongational viscosity
Correlation between on-line and off-line assessment of rheological and
textural parameters
Perspectives
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
PERSPECTIVES : NEW DIES ?
(p21)
Breaker plates
iaal D. Bounie, E. Van Hecke : High moisture extrusion - Sydney, dec. 2nd 97
• Baird D.G., 1976. Fluid elasticity measurements from hole pressure error data. J. Appl. Polym. Sci, 20, pp 3155-3173.• Bhattacharya M. and Padmanabhan M., 1992. Extrusion processing : texture and rheology. In : Encyclopedia of Food and Science Technology, Hui Y.H. Ed., Willey Interscience, New York, pp 800-814.• Bhattacharya M., Padmanabhan M. and Seethamraju K., 1994. Uniaxial extensional viscosity during extrusion cooking from entrance pressure drop method. J. Food Sci., 59(1), pp 221-226, 230• Bouvier J.M. and Gelus M., 1994. Apport des mesures en ligne à l’analyse du procédé de cuisson-extrusion. In : La Cuisson-Extrusion, Colonna P. and Della Valle G. Eds., Tec & Doc Lavoisier, Paris, pp 323-355.• Cheftel J.C., Kitagawa M. and Quéguiner C., 1992. New protein texturization processes by extrusion cooking at high moisture levels. Food Rev. Int., 8(2), pp 235-275.• Cheftel J.C., Kitagawa M. and Quéguiner C., 1994. Nouveaux procédés de texturation protéique par cuisson-extrusion à teneur élevée en eau. In : La Cuisson-Extrusion, Colonna P. and Della Valle G. Eds., Tec & Doc Lavoisier, Paris, pp 45-84.• Cheftel J.C. and Dumay E., 1993. Microcoagulation of proteins for development of "creaminess". Food Rev. Int., 9(4), pp 473-502.• Della Valle G. and Vergnes B., 1994. Propriétés thermophysiques et rhéologiques des substrats utilisés en cuisson-extrusion. In : La Cuisson-Extrusion, Colonna P. and Della Valle G. Eds., Tec & Doc Lavoisier, Paris, pp 439-467. • Harper J.M., Rhodes T.P. and Wanninger L.A., 1971. Viscosity model for cooked cereal doughs. A.I.Ch.E. Symposium Series, 676(108), pp 40-43.• Malkus D.S., Pritchard W.G. and Yao M., 1992. The hole-pressure effect and viscosimetry. Rheol. Acta, 31, pp 521-534.• Mc Master T.J., Senouci A. and Smith A.C., 1987. Measurements of rheological and ultrasonic properties of food and synthetic polymer melts. Rheol. Acta, 26, pp 308-315.• Mitchell J.R., Areas J.A.G. and Rasul S., 1994. Modifications chimiques et texturation des protéines à faible teneur en eau.. In : La Cuisson-Extrusion, Colonna P. and Della Valle G. Eds., Tec & Doc Lavoisier, Paris, pp 85-104.• Padmanabhan M. and Bhattacharya M., 1991. Flow behavior and exit pressures of corn meal under high-shear-high-temperature extrusion conditions using a slit die. J. Rheol., 35(3), pp 315-343.• Padmanabhan M. and Bhattacharya M., 1992. Rheological measurement of fluid elasticity during extrusion-cooking. Trends in Food Science and Technology, 6, 149-151.• Quéguiner C., Dumay E., Cavalier-Salou and Cheftel J.C., 1991. Application of extrusion cooking to dairy products : preparation of fat analogues by microcoagulation of whey proteins. In : Applied Food Extrusion Science, Kokini J. and al. Eds., Dekker, New York, pp 363-376.• Quéguiner C., Dumay E., Cavalier-Salou and Cheftel J.C., 1992. Microcoagulation of a whey protein isolate by extrusion cooking at acid pH. J. Food Sci., 57, pp 610-616.• Remsen C.H. and Clark J.P., 1978. A viscosity model for a cooking dough. J. Food Process Eng., 2, pp 39-64.• Ross-Murphy S.B., 1988. Small deformation measurements. In : Food Structure : its Creation and Evaluation, Blanshard J.M. and Mitchell Eds., Butterworth, London, pp 387-400.• Roussel L., 1996. Making meat products using extrusion technology. Extrusion Communiqué, nov-dec, pp 16-18.• Thiebaud M., 1995. Texturation par cuisson-extrusion de mélanges protéiques hydratés à base de surimi de poisson. Influence des paramètres opératoires et de la formulation sur les caractéristiques biochimiques et physicochimiques des extrudats. PhD. Thesis, University of Montpellier.• Tolstoguzov V.B., 1986. Functional properties of protein-polysaccharides mixtures. In : Functional Properties of Food Macromolecules, Mitchell J.R. and Ledward D.A. Eds., Elesevier Applied Science Pub., London, pp 385-415.• Vergnes B., Della Valle G. and Tayeb J., 1990. Rheopac : a new on-line rheometer with controlled feed rate to determine the viscosity of starchy products. In : Proceedings of ACoFoP2, 13-14 nov. 1990, Bimbenet J.J. and Trystram G. Eds., Paris.• Vergnes B., Della Valle G. and Tayeb J., 1993. Rheopac : a specificin-line rheometer for extruded starchy products. Design, validation and application to maize starch. Rheol. Acta, 32, pp 465-476.• White S.A, Gotsis A.D. and Baird D.G., 1987. Review of the entry flow problem : experimental and numerical. J. Non-Newtonian Fluid Mech., 24, pp 121-160.
BIBLIOGRAPHY
(p22)
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