Understanding Maillard-type reactions in food … · Understanding Maillard-type reactions in food...

Understanding Maillard-type

reactions in food processing

Case study: Extrusion

Imre Blank

Nestlé PTC Orbe, Switzerland

Nancy, September 17, 2012

Goal: Better control of the Maillard reaction cascade

under food processing conditions

Food processing: Extrusion

Holistic approach

Food chemistry: Flavour formation

Targeted approach

11th International Congress on the Maillard reaction 2

O

OHO

CH3

CH3

Mucilon_dissolution.wmv

Extrusion with direct expansion A multi unit operation process

Flour Mix (~10% H2O)

Water, Oil, ...

Steam

Expansion 10%

~15–20%

~5-10%

Moisture:

110–180°C

80–170 bars

Average residence time: 20–30 seconds

3 11th International Congress on the Maillard reaction

Extrusion is an integrated process in

which raw materials rich in starch and

protein are plastified and structure-

modified in a cylinder under pressure

and shear at elevated temperatures

followed by expansion of the die at

the end of the extruder.

Parameters affecting product quality

Extrusion

Heat load (T, t)

Screw speed, SME

Moisture

Number of barrels

Slurry vs. dry addition

…

Recipe

Ingredients

Specific precursors

Concentration, ratio

Catalyst

pH

…

4

Study the effect of extrusion parameters and recipe composition

on furaneol formation from rhamnose and lysine

Identify recipe and processing conditions during extrusion of rice

flour favouring the formation of caramel flavour while considering

physico-chemical properties of the final product

NH2 OH

O

NH2 O

OHO

CH3

CH3

+ Recipe & Process

parameters

11th International Congress on the Maillard reaction

Experimental design: Key product attributes are

affected by both recipe and extrusion parameters

Recipe parameters • pH

• Ratio Rha/Lys

• Phosphate

Extrusion parameters • Moisture levels

• Screw speed

• Temperature

• Residence time

• Slurry vs. dry

Mixing

Extrusion

Drying

Milling

Final product

Product characterisation

• Texture

• Crispness

• Colour

• Flavour

• Acrylamide

• Starch degradation

• Granulometry

• Viscosity

• Sensory

Fractional factorial design:

- 32 instead of 576 trials

- Determining all main effects and

two-factor interactions of 3 recipe

and 5 process parameters

Holistic product characterisation:

- Chemical, physical, sensorial

- Using 16 methods

500 400 300 Screw speed (rpm)

150 135 120 Temp. (°C)

0.134 0.035 PO4 (mol/kg)

23 20 17 Moisture (%)

Slurry Dry Addition

7 5 Barrel length

3:1 3:0 Rha:Lys

7.7 6.4 pH

SME

5

• Trained panel (14 panelists)

• Product – Extruded powder (85%)

– Sugar (15%)

• Reconstitution – 12.4g product

– 100mL milk at 70°C

• 32 Products evaluated vs. reference

• Identification of statistically relevant

trends

Parameters units Low Medium High

pH 6.4 7.7

Rha:Lys 3:0 3:1

Phosphate mol/kg 0.035 0.134

Moisture % 17 20 23

Screw speed rpm 300 400 500

T °C 120 135 150

length barrel short long

Addition dry slurry

Sensory assessment Reconstituted products from experimental design

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

tEasySwallow

aLump

tSmooth

Burnt

Nutty

aDark

Caramel

Toasted

Processy

Off

Overall

acid

WholeGrain

Mushroom

astringent

bitter

aftertaste

t1Thick

tThick

tFluffy

t1Wettability

tSemolina

Cooked

Milky

Rice

Vanilla

sweet

Range covered by A01-A32 (vs. REF)

Fla

vor

Textu

re &

Appeara

nce

Range of sensory attributes

Wide diversity of sensory perception


Mucilon_dissolution.wmv

Colour generation

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

tEasySwallow aLump

tSmooth

Burnt Nutty

aDark

Caramel Toasted

Processy

Off Overall

acid WholeGrain Mushroom

astringent bitter

aftertaste

t1Thick tThick tFluffy

t1Wettability tSemolina

Cooked Milky Rice

Vanilla sweet

Range covered by A01-A32 (vs. REF)

Sensory

im

pact

Colour development Modulation of colour in product through recipe

Browning reactions

-6 -4 -2 0 2 4 6

pH 6 pH 7

Rha:Lys 3:0 Rha:Lys 3:1

Phosphate low Phosphate high

17% H2O 20% H2O 23% H2O

300rpm 400rpm 500rpm

120°C-Long 120°C 135°C 150°C

Dry Slurry

Colour (C)

** Lysine

* High pH

Key p

ara

mete

rs

Light Dark

pH 6

Rha/Lys 3:0

pH 7

Rha/Lys 3:1


Furaneol formation Free amino acids, moisture, T and phosphate are most critical

-6 -4 -2 0 2 4 6

pH 6.4pH 7.7

Rha:Lys 3:0Rha:Lys 3:1

Phosphate 0.035 mol/kgPhosphate 0.134 mol/kg

17% H2O20% H2O23% H2O

300 1/min400 1/min500 1/min

120 °C-Long120 °C135 °C150 °C

DrySlurry

Furaneol ext / mol% Furaneol dry / mol%

Conversion of rhamnose to furaneol

can be modulated through

1. changes of extrusion and/or

2. recipe parameters


O

O OH

Acrylamide Temperature is most critical

-75 -50 -25 0 25 50 75

pH 6.4

pH 7.7

Rha:Lys 3:0

Rha:Lys 3:1

Phosphate 0.035 mol/kg

Phosphate 0.134 mol/kg

17% H2O

20% H2O

23% H2O

300 1/min

400 1/min

500 1/min

120 °C-Long

120 °C

135 °C

150 °C

Dry

Slurry

Acrylamide


-6 -4 -2 0 2 4 6

pH 6.4pH 7.7



17% H2O20% H2O23% H2O

300 1/min400 1/min500 1/min

120 °C-Long120 °C135 °C150 °C

DrySlurry

Furaneol ext / mol% Furaneol dry / mol%

O

O OH

NH2

O

Mitigation

options

Structure and Texture Moisture and temperature are most critical

-1500 -1000 -500 0 500 1000 1500

pH 6.4pH 7.7



17% H2O20% H2O23% H2O

300 1/min400 1/min500 1/min

120 °C-Long120 °C135 °C150 °C

DrySlurry

Visco5min / mPas ViscoMax / mPas


Structure = f (SME)

Texture = f (SME)

-15 -10 -5 0 5 10 15

Cell walls / µm

Semolina Crispy Low High

Long Chain

DP~50

Short Chain

DP~25

0

20

40

60

80

100

0 50 100

SME

Sta

rch

(%

)

Amylopectin

High MW

intermediate

Low MW

intermediate

Starch degradation MW = f (SME)

11

Rice Flour

Moisture % 8-13

Starch %d.b. 88-92

Total fibers %d.b. 0.3-1

Proteins %d.b. 6-9

Fat %d.b. 0.5-1

Ash %d.b. 0.3-1

0

1000

2000

3000

4000

5000

6000

0 2 4 6 8 10 12

Vis

co

sit

y (

mP

a.s

)

Time (min)

SM

E 9

2

SM

E 3

5

Viscosity = f (MW) High H2O

High T

Low H2O

Low T

SME 92 SME 35

Effect of recipe/extrusion parameters Options for flavour optimization

pH 6pH 7

Rha:Lys 3:0

Rha:Lys 3:1

Phosphate low

Phosphate high

17% H2O

20% H2O

23% H2O

300rpm

400rpm

500rpm

120°C-Long

120°C135°C

150°C

Dry

Slurry

-4

-3

-2

-1

0

1

2

3

4

-20 -15 -10 -5 0 5 10 15 20

SME-measured

%F

ura

ne

ol-

dry

Temperature affects both

furaneol and SME

150°C → more viscous

Free amino acid and

phosphate affect

furaneol, but not SME

Moisture affects both

furaneol and SME

17% → less viscous


Next step:

Full factorial design in a

smaller space for final

product optimisation

Goal: Better control of the Maillard reaction cascade

under food process conditions

Food processing: Extrusion

Holistic approach

Food chemistry: Flavour formation

Targeted approach - CAMOLA

11th International Congress on the Maillard reaction 13

0.15 mmol [12C6]-glucose

0.15 mmol [13C6]-glucose

0.1 mmol glycine or proline

1 mL 0.5 M phosphate buffer pH 5, 7 or 9

Heating:

135°C/20min

O

OHO

CH3

CH3

Glucose + Proline Furaneol

Major pathways

• Aqueous systems: Intact skeleton at pH 5; recombination of C3+C3 at pH 7 and 9

100%

26%

14%

0%

52% 56%

0%

12%

18%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Aqueous system

Intact skeleton C3+C3

C2+C4 C5 +C1Glc

C5 +C1Gly


100% 96%

84%

0% 0% 4%

0% 4%

12%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Dry system


C2+C4 C5 +C1Glc

C5 +C1Gly

Major pathways


• Dry systems: Intact skeleton (>84%)

Major pathways


• Dry systems: Intact skeleton (>84%)

• Rice: Intact skeleton (>80%), some recombination of sugar fragments at pH 7 and 9

98%

85% 80%

0%

6% 10%

0%

8% 10%

0% 0% 0% 2% 1% 0% 0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Rice Model


C2+C4 C5 +C1Glc

C5 +C1Gly Inherent prec. Rice

Glucose + Glycine Furaneol

100%

70%

60%

0%

18%

26%

0%

8% 8%

0% 0% 4%

0% 4% 2%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Aqueous system


C2+C4 C5 +C1Glc

C5 +C1Gly

100% 98% 96%

0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 2% 4%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Dry system


C2+C4 C5 +C1Glc

C5 +C1Gly

Major pathways

• Aqueous systems: Intact skeleton at pH 5; less relevant with increasing pH

• Dry systems: Intact skeleton independent of pH

• Rice models: Intact skeleton independent of pH, only little by sugar fragmentation

94% 94% 92%

0% 0% 2% 0% 0% 4%

0% 0% 0% 0% 4% 2%

6% 2% 0%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Rice Model


C2+C4 C5 +C1Glc



Glucose + Glycine Furaneol (pH 7)

• Aqueous system: Intact skeleton (major) and C3+C3 recombination (minor)

• Dry system: Intact skeleton (almost exclusive)

• Rice model: Intact skeleton (almost exclusive)

• Extrusion: Intact skeleton (almost exclusive), about 8% from inherent precursors

100%

70%

60%

0%

18%

26%

0%

8% 8%

0% 0% 4%

0% 4% 2%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Aqueous system


C2+C4 C5 +C1Glc

C5 +C1Gly

100% 98% 96%

0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 2% 4%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Dry system


C2+C4 C5 +C1Glc

C5 +C1Gly

94% 94% 92%

0% 0% 2% 0% 0% 4%

0% 0% 0% 0% 4% 2%

6% 2% 0%

0%

25%

50%

75%

100%

pH 5 pH 7 pH 9

Rice Model


C2+C4 C5 +C1Glc


92%

0% 0% 0% 0%

8%

0%

25%

50%

75%

100%

pH 7

Extruded system

Intact skeleton

Inherent prec. Rice


CH2OH

OH

OH

OH

OH,OH

OH

OH

OH

O

O

CH3

CH3

O

OH

OH

O

CH3

CH3

O

CH3

OH

O

N COOH

H

O

CH3

OH

OH

CH3

O

- H2O

N, H2O, CO2

HDMF

O

O

CH3

OH

O

OH

OH

O

OH

OH

O

CH3

CH3

O

OH

OH

O

CH3

O

CH3

OH

OH

CH3

O

- H2O

CH3

O

CH3

OH

O

N COOH

H

N, H2O, CO2

HDMF

Roasting: 0%

Solution: 60%

Acetylformoin

(Schieberle et al., 2003; Schieberle, 2005)

Roasting: 100%

Solution: 40%

Formation of Furaneol

Model systems:

• Furaneol is mainly formed from intact glucose skeleton

• Except in aqueous systems at weak basic pH where fragmentation is dominating

Food system & extrusion:

• Furaneol is almost exclusively formed from the intact glucose skeleton

Conclusions & Outlook

• Flavour generation can be modulated and optimised with respect to other food

product attributes (colour, texture, …)

• The holistic approach based on experimental design and a global product

characterisation allows rapid optimisation of recipe and extrusion parameters

• This requires an integrated approach of various scientific and engineering

disciplines


• Better understanding of chemical reactions taking place and their interactions

during food processing (targeted experiments, CAMOLA, …)

• Better understanding of material properties and transformation in Maillard

systems

• Better integration of food physics & engineering (e.g. physical state, Tg, heat

load) in our Maillard world to achieve better control

Ensuring product quality by extrusion

Future focus

Hélène Chanvrier PTC Orbe Structure, texture

Tomas Davidek PTC Orbe Flavour, acrylamide

Daniel Festring PTC Orbe Flavour, processing

Valérie Leloup PTC Orbe Macromolecular chemistry

Werner Pfaller PTC Orbe Extrusion

Andreas Rytz NRC Lausanne Experimental design

Silke Illmann Univ. Karlsruhe Diploma work (Prof. H. Schuchmann)

Rosa Delgado Sanchez Univ. Sevilla PhD thesis (Prof. F. Hidalgo)

Lara S. Kirsch TU Munich Master thesis (Prof. T. Hofmann)

Thanks to…

… and to you for your kind attention ! 19 11th International Congress on the Maillard reaction

Understanding Maillard-type reactions in food … · Understanding Maillard-type reactions in food...

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