Key microstructural and rheological parameters underlying ... · Key microstructural and...

Key microstructural and rheological

parameters underlying the

functionality of roll-in shortenings

A.G. Marangoni, B. Macias Rodriguez, F.M. Peyronel

University of Guelph, ON, Canada

2

TAG MOLECULES

Structural hierarchy in fats

Acevedo and Marangoni. (2010). Cryst. Growth. Des (10): 3327-33

Roll-in Shortening

• Stiff but plastic fats used in the manufacture of puff-pastry

• High trans (TFA) and saturated (SFA) fatty acids content

66% SAFA+TFA (w/w) (risk of cardiovascular health)

3

Microstructure, Mechanical and Physical Properties of Roll-in Shortening

• Microstructure: 3-D network

structured by primary and secondary

interactions

• Yield value criteria for roll-in

shortenings (Haighton 1959): 800-

1600 (g/cm2) : puff pastry.

Shortening A: fully crystallized in line, B: partially. Adapted from:

Heertje. (2014). Food Struc.

Strain ()/ln (ho/h)

Str

ess

()/

kP

a

A

B

1

2

4

A B

Research Justification and Question

• Limited understanding of the structural and physical properties governing the mechanical behavior (“functionality”) of roll-in shortenings.

• Attempts to reduce SAFA and TFA in roll-in shortenings unsatisfactory (brittle/soft).

• Global trend to reduce SFA and TFA

5

Which rheological property determines the functionality

of roll-in shortening?

Shortening name Manufacturer Composition

Puff-flake (hydrogenated) (1) Bunge Hydrogenated soybean oil and

cottonseed oil

SPS NH special pastry (non-

hydrogenated) (2)

Bunge Canola, modified palm and palm

kernel oils

SPS special pastry (3) Bunge Hydrogenated vegetable oil and

modified

All-purpose (4) Palm oil and modified palm

For pays (5) Bunge Interesterified soybean oil

All-purpose (6) ADM Interesterified soybean oil

Icing (7) Cargill Palm oil

*-shortening (8) In-house Hydrogenated soybean oil, soybean

oil, glycerol monopalmitate

6

Shortening Used in Study

*Used only for rheological characterization

7

Shortening Description

1 Roll-in hydrogenated soybean and

cottonseed oils

2 Roll-in non hydrogenated canola oil,

modified palm and palm kernel oils

3 Roll-in hydrogenated vegetable and

modified palm oils

4 All-purpose non hydrogenated palm and

modified palm oils

5 Pays interesterified soybean oil

6 Cake interesterified soybean oil

7 Icing palm oil

8 *Fully hydrogenated soybean oil,

soybean oil and glycerol monopalmitate.

Fatty acid composition

8

Fatty acid Sample

1 2 3 4 5 6 7

12:0 5.0

14:0 2.5 1.1 1.1

16:0 13.3 30.0 20.5 45.1 11.4 12.4 45

18:0 16.7 3.4 13.4 4.8 31.2 33.6 5.1

18:1 (c9) 25.9 40.4 27.9 39.2 17.5 16.5 39.0

18:1 (t9) 9.5 13.9

18:2 (t9, 12) 19.8 8.9

18:2 (c9, 12) 13.7 12.5 14.7 9.9 35.1 33.9 8.9

18:3 (3) 1.1 6.2 0.8 4.8 3.6

SFA+TFA 59.3 40.9 56.7 51 42.6 46 51.2

Melting and SFC profiles

9

Data sets colored red correspond to roll-in shortening

A

B

0 10 20 30 40 50 600

10

20

30

40

50

60

1

2

3

4

5

6

7

Temperature (°C)

SF

C (

%)

10 20 30 40 50 600

2

4

6

51.8

47.9

50.4

44.3

52.8

50.8

41.6

Temperature (C)

He

at

flo

w (

W/g

)

1

2

3

4

5

6

7

Polymorphism (WAXS)

10 15 20 25 30

0

5000

10000

15000

'

> '

'>

'

'

'>

'>

2 ()

4.24.6

3.83.6

1

2

3

4

5

6

7

Inte

ns

ity

(a

.u.)

B

Mechanical properties: small deformation

Test conditions

Sample (201.5 mm DIAthickness)

Loading (3 N force control)

Sand blasted plate-plate geometry

Input: (0.001-100%) (= 6.28 rad/s)

Output: G’, G’’, * when G’ decreases 5%

(ISO 6721-10)

𝐽 𝑡 = 𝐽0 + 𝐽1 1 − 𝑒𝑥𝑝 −𝑡

Λ+

𝑡

𝜂0

Rotational rheology

(Creep and recovery) Oscillatory rheology

Test conditions

Stress step: 200 Pa (within LVR)

Loading/unloading time: 5/10 min

Burger Model

𝐽 𝑡 = 𝐽𝑚𝑎𝑥 − 𝐽0 − 𝐽1 1 − 𝑒𝑥𝑝 −𝑡

Λ

Creep

Recovery 11

J0

J1

0

t1 t2 t3 t4

J

Jmax

S1

D2

S2

D3

Small deformation rheology

12

G’: Elastic modulus, and *: yield stress. Data sets colored red corresponded to

roll-in shortenings.

1 2 3 4 5 6 7 80

200

400

600

800

aa

a

b

cc

a

b

Sample

* (P

a)

1 2 3 4 5 6 7 80

1000

2000

3000

4000

a,c

b

c,d

b

aa,c

bb,d

Sample

G' (k

Pa

)

A B

Creep and recovery

13

J0 10-7 (Pa-1) J1 10-7 (s) 0 108 (Pa s)

1 7.40.4 3.70.9 27.17.1 4.60.5

2 4.61.8 2.21.0 21.75.0 9.831.9

3 5.71.8 2.20.7 16.21.34 12.52.0

4 12.60.8 12.92.3 18.12.4 1.60.2

8 6.71.4 2.00.7 14.34.7 6.51.7

0 200 400 600 8000

2.0×10 -6

4.0×10 -6

1

2

4

8

3

t (s)

J (

Pa

-1)

J0, J1: instantaneous and retarded compliance, : retardation time,

0 : zero-shear viscosity

14

Mechanical properties: large deformation

Uniaxial compression Cone penetrometry

𝜺𝒉 = 𝟏

𝒉

𝒉

𝒉𝟎

𝒅𝒉 = 𝒍𝒏𝒉

𝒉𝟎

𝝈 =𝑭

𝑨

0.2 0.4 0.6 0.80

20

40

60

80Eapp

y

h

(

kP

a)

𝜀 ℎ = 0.125 𝑠−1 (strain rate)

Test conditions

2010mm (DIAthickness)

70% compression, 16 °C

Test conditions

𝐶 = 𝐾𝑊/𝑝1.6

AOCS method Cc 16-60

Large deformation rheology

15

0

20

40

60

80

(

kP

a)

0.2 0.4 0.6 0.8h

0.2 0.4 0.6 0.80

20

40

60

80

h

(

kP

a)

Roll in All-purpose

Interesterified Icing

: true stress, h: true strain.

16

Large deformation rheology

Eapp: apparent Young modulus (kPa), *: yield stress, C: yield value.

Data sets colored red correspond to roll-in shortening

A

1 2 3 4 5 6 7 80

2

4

6

8

a

b

a

c

d

a

b

a

Sample

*(

kP

a)

1 2 3 4 5 6 7 80

5

10

15

C (

kP

a)

a aa

b

c

a

dd

Sample

B

C

1 2 3 4 5 6 7 80

2

4

6

8

10

a,c,e

b

a,d

a,b

a,d

c,da,d

b,e

Sample

Ea

pp

Strain sweep of an all-purpose shortening at a fixed frequency (6.28 rad/s). Small amplitude

(SAOS) and large amplitude oscillatory rheology (LAOS). Lower left inset 1: linear region, 2: non

linear region, 3: stress overshoot, 4: plastic flow

Rheological Properties

17

SAOS

LAOS

Lissajous curves (Linear regime)

Large Deformation Rheology

19

Elastic moduli

𝐺′𝑀 ≡ⅆ𝜎

ⅆ𝛾 𝛾=0 = 𝑛𝐺′

𝑛 = 𝑒1 − 3𝑒3𝑛 𝑜𝑑𝑑

+⋯ ,

𝐺′𝐿 ≡𝜎

𝛾 𝛾=±𝛾0 = 𝐺′

𝑛 −1 𝑛−1 /2 = 𝑒1 + 𝑒3𝑛 𝑜𝑑𝑑

+⋯ ,

Viscous moduli

𝜂′𝑀 ≡ⅆ𝜎

ⅆ𝛾 𝛾 =0 =

1

𝜔𝑛 𝑛𝐺′′

𝑛 −1(𝑛−1)2 = 𝑣1 − 3𝑣3

𝑛 𝑜𝑑𝑑

+⋯ ,

Dynamic viscosity

𝜂′𝑀 ≡ⅆ𝜎

ⅆ𝛾 𝛾=0

=1

𝜔𝑛𝐺"

𝑛(−1)(𝑛−1)/2= 𝑣1 − 3𝑣3

𝑛 𝑜𝑑𝑑

+⋯ ,

𝜂′𝐿 ≡𝜎

𝛾 𝛾=±𝛾0 =

1

𝜔𝐺"

𝑛 = 𝑣1 − 3𝑣3𝑛 𝑜𝑑𝑑

+⋯ ,

, 𝜸

Fig 7. Illustration of viscoelastic moduli

𝜂′𝐿 ≡𝜎

𝛾 𝛾 =±𝛾 0 =

1

𝜔𝑛 𝑛𝐺′′

𝑛 = 𝑣1 + 𝑣3𝑛 𝑜𝑑𝑑

+⋯ ,

Source: Ewoldt et al., (2008)

20

Lissajous curves of shortenings. Lower insets share the same aspect ratio of sample 1.

1) Roll-in, 2) All-purpose, 3) Interesterified

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

-0.02 -0.01 0.00 0.01 0.02 -0.003 -0.001 0.001 0.003

-1200

-700

-200

300

800

-0.04 -0.02 0.00 0.02 0.04

1 2

3

Lissajous curves (linear-to-nonlinear)

Thixotropy

Fig 6. Thixotropy. 1: Constant deformation (CSD) at = 6.28 rad/s and = 0.001% (in LVR),

2: CSD at same and =5% (out LVR). 3: CSD as interval 1.

t1 t2 t3

G’

1

2

3

21

22

Figure 12. Thixotropic behavior of selected shortenings (structural regeneration phase) .

: SPS NH special pastry G’0 = 3546 kPa, recovery: 93%, : All-purpose G’0 = 3862 kPa,

recovery: 82% .

0

1000

2000

3000

4000

0 50 100 150

G'

(kP

a)

t(s)

23

~50 kPa

Rheological Behavior under different normal forces

Viscoelastic properties of roll-in shortenings at increasing pressures.

Yield zone: from * to G’=G’’. Lower left inset shows a sketch of roll-in sheeting.

24

Strain-stress curves of selected shortenings at a fixed frequency (6.28 rad/s). Roll-in:

Shortening SPS.

Stress overshoots and brittleness/plasticity

Structural Origins of Rheological Behavior?

Scattering

Atomic features 1-20 Å

~1 105Å or 10 µm

~200Å or 0.02 µm

?

26

Aggregation? Fractal? size?

More

aggregation?

USAXS

length scale =2 π

q

X-Ray Scattering

Scatterer Shape? Size?

Molecular features ~150 Å

USAXS reveals nanocrystal fractal aggregation for SSS in OOO

27

M.F. Peyronal et al. 2013, Applied Physics Letters M.F. Peyronal et al. 2014, J. Physics: Condensed Matter M.F. Peyronel et al. 2014, Current Opinion in Colloid and Interface Science M.F. Peyronel et al. 2014, Food Biophysics M.F. Peyronel et al. 2015, Applied Physics Letters D.A. Pink et al. 2015, J. Physics D: Applied Physics

Fat polycrystal formation is similar to a colloidal aggregation process

28

D.A. Pink et al., 2013, J. Applied Physics Quinn, B. et al., 2014. J . Physics : Condensed Matter

Physical Structural Levels in Fats

29 Peyronel et al. 2014- Lipid Technology , 2014

Surface Morphology Ds

Dm Dm = 1

D

USAXS of shortening

30

1, 2 and 3: roll-in shortenings. 4: all-purpose shortening. P

Sample P1 Rg1 P2

Rg2

1 3.90.1 62260.5 1.70.0 8024403

2 3.70.0 76053.5 2.60.1 48121734

3 3.70.0 54036 2.10.1 4162.51776

4 3.70.0 8040630 - -

0.0001 0.001 0.01 0.1

100

105

1010

1234

q[Å-1]

Inte

ns

ity

lo

g I(q

) [c

m-1

]

Acknowledgements

Natural Sciences and Engineering Research Council

Canada Research Chairs Program

Ontario Ministry of Agriculture and Food

Coasun Inc.

Thank You!

Thank You!