maillard-type reactions in food - perspectives and ... · 2007-09-04 nestle ptc orbe / i. blank /...
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2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 1
Maillard-type reactions in food
- Perspectives and constraints -
9th International Symposium on the Maillard Reaction,
Munich, September 1–5, 2007
Imre Blank
Nestlé Product Technology Centre, Orbe, Switzerland
2
Definition of the “Maillard reaction”
The “Maillard reaction” is a special case of the amino-carbonyl reactions of reducing sugars and amino acids or derivatives thereof
→ Amine assisted carbohydrate degradation
Goal: Better control of the Maillard reaction cascade
☺ Aroma
☺ Taste
☺ Colour
☺ Antioxidants
☺ Health benefits
☺ Texture
� Nutritional value loss
� Shelf-life issues
� Toxic compounds
∆T
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 3
(Hodge, 1953)
The Maillardreaction cascade
�Amino-carbonyl reaction
�Dehydration
�Enolisation
�Decarboxylation
�Cyclisation
�Hydrolysis
�Oxidation
�Reduction
�Retro-aldol reaction
�Radical reaction
�Disproportionation
�Canizzaro reaction
�Retro-Claisen reaction
�Acyloin reaction
�Baeyer-Villiger rearrangement
�Benzilic acid rearrangement
�and others …
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 4
OH
OH
NH
O
COOHOH
OH
O
NH
O
COOHOH
OH2
OH
O
OH OH
CH2OH
OH
O
OH O
CH3OH
O
O
OH OH
CH3
NH2
COOHOH
2
OH
OH
OH
N
OH
OHCOOH
OH
OH
OH
NH
OH
OHCOOH
OH
OH
OH
NH
O
OHCOOH
O
OH
OH
NH
OH
OHCOOH
OH2OH
2
O
OH
OH
OH
OH
OHNH
2COOH
I
OH
OH
OH
NOH CH
2
CO2
OH
OH
OH
NH2
OH
OH2
CH2
O
OH2
OH
O
OH
OH
OH
NH
COOH
CH2
N
N
COOH
CH2
COOH
e-
OH2
CH2
N
N
COOH
CH2
COOH
+.
OH
OH
NH
+
OH
COOHOH
OH
OH
O
O
OH
O CHOOH
H+
H+
OH2
OH2
NH2
COOH
OH2
NH2
COOH
OH
OH
N
O
OH
OHCOOHO
OH OH
OH
COOHNOH
O
OH OH
OH
CH2
N
O
OH OH
OH
NH2
OH
OH
O
O
OH
OH
IX
X
XI
O2/Me2+
OH2
CO2 OH
2,
OH2
CH2
O
(Davidek et al., 2002)
Means of control
• Composition
• Concentration
• pH
• Catalyst
• Heat load (t, T)
• Redox state
• React. medium
• Physical state
• Structure
• Molecular
organisation
• Moisture
• Water activity
• …(pH > 6)
(pH < 6)
Oxidation
Decarboxylation
Dehydration 2,3-Enolisation
1,2-Enolisation
Retro-aldol
OH
OH
OH
NH
OH
COOHOH
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 5
12 Symptoms of the Maillard reactionA highly complex system
• Lowering of pH
• Increasing reducing power
• Decreasing solubility
• Chelation of metals
• Production of fluorescence
• Production of colour and discoloration
• Production of flavour and off-flavour
• Production of water
• Production of carbon dioxide
(H.E. Nursten)
• Loss of vitamin C activity
• Loss of biological value of protein
• Production of toxicity
Chemistry
Physico-chemistry
Biochemistry
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 6
in-vitro in-vivo in-food
Analyticsnon-volatilesvs. volatiles
InteractionsMaillard / lipids /
polyphenols
Mechanismsmajor vs. minor
pathways
Food physicswater activity /food structure
Outline of the presentation
Positive effects
Aroma formation
→ Structured fluids
Taste chemistry
→ Taste, modulators
Protection
→ Antioxidative activity
Positive effects
Aroma formation
→ Structured fluids
Taste chemistry
→ Taste, modulators
Protection
→ Antioxidative activity
Pleasure
Pleasure
Health
PleasurePleasure
PleasurePleasure
HealthHealth
Negative effects
Loss of nutritional value
→ Lysine blockage
Shelf-life issues
→ Browning
Process contaminants
→ Acrylamide
Negative effects
Loss of nutritional value
→ Lysine blockage
Shelf-life issues
→ Browning
Process contaminants
→ Acrylamide
Nutrition
Quality
Safety
NutritionNutrition
QualityQuality
SafetySafety
How to control the Maillard reaction cascade ?
7
Mechanistic AspectsMechanistic AspectsMechanistic AspectsMechanistic Aspects
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 8
“Peeling-off” mechanism of αααα-glucanto 1,4-dideoxyhexosulose
(Kroh & Schulz, 2001; Hollnagel & Kroh, 2002)
Solid-state MR conditions
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 9
3,4-Dideoxypentosulose from oligosaccharides (1,4-glycosides)
(Mavric et al. 2004; Mavric & Henle, 2006)
New imidazolinone resulting from
the reaction of peptide-bound
arginine and oligosacccharides
with 1,4-glycosidic linkages
Nδδδδ-[5-(3-Hydroxypropyl)-4-oxo-imidazolon-2-yl]-L-ornithine (PIO)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 10
3-Deoxypentosulose: A new majorαααα-dicarbonyl from oligosaccharides
(Kroh & Schulz, 2001; Hollnagel & Kroh, 2002)
3-deoxypentosulose
(Aqueous milieu)
Oxidation or
H-abstraction
11
Aroma GenerationAroma GenerationAroma GenerationAroma Generation
12
Norfuraneol as key intermediate to generate various functionalities
CHO
CH-OH
(CH-OH)2
CH2-OH
Pentose
∆∆∆∆T
O
OH O
C2 + C3
Sugar fragments
∆∆∆∆T
CHO
CH-OH
(CH-OH)3
COOH
Uronic acid
∆∆∆∆T
CHO
CH-OH
(CH-OH)2
CH2-O-P
Pentose-5-P
∆∆∆∆T
Colour
OO
O
OH O
O
O
O
OH O
O
Antitumor agent
O
O
Sulphur
Aroma
O
SH
source
Taste
O
ON
N
H
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 13
Means of control: Use of mesophases as reaction medium
Micelles (L2 phase) Lamellar phase Cubic phase
Monoacylglyceride
(Monoolein)
+H2O
Hexagonal phase
CH2OH
CH
CH2O
OH
O
Self-assembly structures (structured fluids) based on monoglycerides
Cubic phase:
• highly viscous
• very large interface
• thermodynamically stable
• polar and apolar solubilisation sites
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 14
Norfuraneol (ug/mmol xyl)
750851
1095
2188
0
500
1000
1500
2000
2500
Buffer Lamellar Cubic Hexagonal
Xylose degradation and norfuraneol formation depend on mesophase
Residual xylose (%)
63
4540
47
0
25
50
75
100
Buffer Lamellar Cubic Hexagonal
(pH 6, 70 °C, 7 h)
(Davidek et al., 2004)
� Higher yields – Concentrated flavor precursor systems� Higher stability – Protection of odorants generated� More specificity – Reactions at the interface (regio-selectivity)
3x
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 15
Reaction conditionsReaction conditions
L-Cysteine (6.7 mmol)
D-ribose (20 mmol)
Phosphate buffer (10 mL, pH 5)
1 g aq. solution + 4 g monoglyceride
Flavour extracted with diethylether
and analysed by GC/FPD and MS
Structured FluidStructured Fluid
Dimodan PV/water (80:20) cubic phase
(Vauthey et al., 2000)
Ribose+
Cysteine
100°C
4 h
Products
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
44
46
48
50
52
54
56
58
60
O
SH
H2O
O
S
O
S
O
S
O
S
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
60
80
100
120
140
160
180
200
220
240
O
SH
O
SH CP
O
S
O
S
O
S
O
S
Time (min)
Structured fluids used as micro-reactors in flavour generation
16
Taste ChemistryTaste ChemistryTaste ChemistryTaste Chemistry
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 17
Taste-active molecules identified in Maillard reaction samples
N
OH
N
OH
Tressl et al.(1985)
Bitter
O
N
O
N
Ottinger et al.(2001)
Cooling
Pabst et al.(1984)
Bitter
OOH
OH
N
OOH
N
N
Frank et al.(2001)
Bitter
O
O
N+
O
OH
O
OH
OH
OH
ON
COOHOH
COOHH
OH
OH
OH
OOH
N
COOK
COOK
H
Umami
Beksan et al.(2003)
Sugar + proline Xyl + Ala Sugar + glutamic acid
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 18
Identification of new bitter tastingmolecules: Indolizinium-6-olates
(Frank & Hofmann, 2001)
Fractionation -> Taste dilution analysis -> Identification (HPLC-MS, 2D-NMR)
O
O
N+
O
OH
O
(TT= 2.5x10-4 µµµµmol/kg water)
Model: xylose/alanine, pH 5, reflux, 3 h
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 19
Comparative Taste Dilution Analysis: Alapyridaine in beef bouillon
20
15
10
5
0
1 2 4 8
TD-factorsignal intensity [λ λ λ λ = 300 nm]
t [min]
8
3
1
2
45
6
7
9
10
taste threshold of
saccharose (50 mmol/L)20
15
10
5
0
1 2 4 8
TD-factorsignal intensity [λ λ λ λ = 300 nm]
t [min]
8
3
1
2
45
6
7
9
10
taste threshold of
saccharose (50 mmol/L)
(Hofmann et al., 2003)
N+
OH
OH
COO-
+
-
N
R COO
OH
OH
O
OH O
NH2
R COOHEtOH / H2O
Hexose
Maillard reaction
Alapyridaine (R= Me)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 20
Natural taste enhancer found in beef bouillon: Alapyridaine
0
1
2
3
0
1
2
3
MSG MSG/Alapyridaine
GMP GMP/Alapyridaine
MSG/GMP
MSG/GMP/Alapyridaine
Inte
nsi t
y o
f u
mam
i n
ot e
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
A
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
0
1
2
3
4
5umami
sweet
sour
bitter
salty
astringent
B
N
OH
OH
COO-
+Glucose
+
Alanine
boiling
(Soldo et al., 2003; WO 03/022817 A1)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 21
Taste modulators: Bitterness inhibitor
0
1
2
3
4
5
A B C D E
Bit
ter n
ess in
ten
sit
y
Samples
+0.02 mmol/L +
0.2 mmol/L
+2 mmol/L
+7 mmol/L
Co
ffee
Taste threshold
of salicine
TD factor
• Combinatorial approach
Pyridinium betaine libraries
• Fractionation, HILIC, cTDA
• Identification, synthesis
(Soldo & Hofmann, 2005; WO 03/022817 A1)
N
OH
OH
COO-
+Glucose
+
Glycine
heating
Glypyridaine
22
Protection Protection Protection Protection
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 23
Health benefits the Maillard reaction products: Recent results
K.-H. Wagner, S. Reichhold, K. Koschutnig, S. Chriot, C. Billaud
The potential antimutagenic and antioxidant effects of Maillard reaction
products used as “natural antibrowning” agentsMol. Nutr. Food Res. 2007, 51, 496 – 504
S. Ruhs, N. Nass, V. Somoza, U. Friess, R. Schinzel, R.-E. Silber, A. Simm
Maillard reaction products enriched food extract reduce the expression of
myofibroblast phenotype markersMol. Nutr. Food Res. 2007, 51, 488 – 495
M. Lindenmeier, V. Faist, T Hofmann
Structural and functional characterization of Pronyl-lysine, a novel protein modification in bread crust melanoidins showing in vitro antioxidative and
phase I/II enzyme modulating activity.
Journal of Agricultural and Food Chemistry (2002), 50, 6997-7006.
→ Antifibrotic → Antioxidative→ Antimutagenic → Chemopreventive
molecular
insight
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 24
Pronylated proteins in bread crust: Chemopreventive activity in-vitro
Lindenmeier et al. (2002, 2004)
… “pronylated” proteins as part of bread
crust melanoidins act as monofunctional
inducers of GST, serving as a functional
parameter of an antioxidant, chemo-
preventive activity in vitro.
… pronyl-L-lysine in bakery products is
strongly dependent on the manufacturing
conditions as well as the recipe.→ Addition of casein and glucose (5-10%)→ Sourdough fermentation
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 25
Pronylated proteins: Chemopreventive activity in-vivo
Somoza et al. (2005)
… the main systemic effects of dietary malt, bread crust, and pronyl-
BSA were demonstrated to be the enhanced antioxidant capacity and
the particulate increase in chemo-preventive enzymes.
Bread crust: GST (kidney)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 26
5
(Marko et al., 2003)
Beneficial effects of the Maillard reaction: Inhibiting tumor growth
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 27
Health effects of Maillard reaction products: Status COST Action 919
“The results obtained for intestinal degradation, and respective implications for gut
health, absorption, and further health effects, such as antioxidant activity, chemo-
preventive activity, and antimutagenic activity, clearly demonstrate that at least
some of the dietary MRPs and melanoidins are health-promoting, while others may
be not.
The challenge for future studies is the chemical characterization of harmful and
beneficial compounds for their structure-specific health effects and the optimization
of food processing technologies for a selective formation of health beneficial MRPs
and melanoidins.”
(V. Somoza,
Mol. Nutr. Food Res.
2005, 49, 663-672)
(Somoza, 2005)
28
Interactions with Lipid OxidationInteractions with Lipid OxidationInteractions with Lipid OxidationInteractions with Lipid Oxidation
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 29
Maillard reaction vs. lipid oxidation
“… both reactions are so interrelated that they should be considered simultaneously
to understand the products of the Maillard reaction
in the presence of lipids and vice versa, and should be included in one general pathway
that can be initiated by both lipids and carbohydrates.”
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 30
Flavour Heat-inducedchemicals
Antioxidants
(Zamora & Hidalgo, 2005)
Interactions between the Maillard
reaction and lipid oxidation
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 31
2-Alkylpyridine
Phenylacetaldehyde
(Reaction: 37 °C, overnight)
Flavour formation: Strecker-type
degradation by 4,5-epoxy-2-elkenals
pHopt ~ 7
(Hidalgo & Zamora, 2004)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 32
Colour development: Formation
of 2-(1-hydroxyalkyl)-pyrroles
(Reaction: 37 °C, overnight)2-(1-Hydroxyalkyl)pyrrole derivatives are highly reactive
and tend to easily undergo polymerisation reactions
(Hidalgo & Zamora, 2004)
- CO2
- CO2
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 33
Highermelanoidin-like
polymers
Colour formation by polymerisation
of pyrrole derivatives
Methylene-bridged polypyrroles
(Zamora & Hidalgo, 2005; Tressl et al. 1998)
2-(1-Hydroxyalkyl)pyrrole
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 34
• Protein modifications: second. + tert. structure, denaturation, dimerisation
• Increased oxidative stress: εεεε-N-pyrrolylnorleucine (Pnl), loss of lysine
BSA + Epoxyheptenal,
pH 7.4, 37 °C
Pnl
(Hidalgo & Zamora, 2000)
Structural modifications of proteins
by epoxyalkenals
Michael adduct of
4,5-epoxy-2-heptenal
with histidine
Polymeric pyrrole cross-links
formed by reaction of lysine
with 4,5-epoxy-(E)-2-heptenal
35
Interactions with PolyphenolsInteractions with PolyphenolsInteractions with PolyphenolsInteractions with Polyphenols
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 36
Formation of Strecker aldehydes from polyphenol-derived quinones
4-Amino-1,2-benzoquinone (6): putative intermediate
in the formation of Strecker aldehydes (0.03-0.4
mol%) from polyphenols under oxidative conditions.
(Rizzi, 2006)
Y = amino acid residue, R = alkyl group; [O] = molecular oxygen
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 37
Trapping of reactive Maillard intermediates by polyphenols
(Totlani & Peterson, 2006; Noda & Peterson, 2007)
Glc/Gly
1,2,3-THB
Me-Gallate
EGCG, ECG, 1,3,5-THB
Epicatechin
O
O
O
OH
OOH
OH
OH
OH
OH
OH
O
OOH
OH
OH
OH
OH
Epicatechin
O
O
(Electrophilic aromaticsubstitution reaction,
hydroxyalkylation)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 38
Polyphenols interfere in the Maillard reaction
• Epicatechin: Quenching of sugar fragmentation products (pressure cooking)
Trapping agent of 3-deoxy-2-hexosulose (roast conditions)
• Phenolic chemistry alters the mechanisms of the Maillard reaction
→ Need for a better understanding of Maillard chemistry in processed food
Co
nc
en
tra
tio
n (
µµ µµg
/mm
ol
glu
co
se
)
16
12
4
8
0
N
N
OH
O
OO
���� Glc/Gly
���� Glc/Gly/EC
N
N
O
O
N
N
O
O
O
O
O
OH
NH
O
(Totlani & Peterson, 2005; 2007)
Maillard precursors
Modified composition
OOH
OH
OH
OH
OH
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 39
Trapping of key odorants (thiols) by polyphenols via oxidative coupling
(Müller & Hofmann, 2007)
The loss of 2-furfurylthiol during coffee storage is mainly due to the oxidative coupling
of the odorant to hydroxyhydroquinone (2), giving rise to the conjugates 9 and 10.
40
Loss of Nutritional Value: Lysine Blockage Loss of Nutritional Value: Lysine Blockage Loss of Nutritional Value: Lysine Blockage Loss of Nutritional Value: Lysine Blockage
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 41
Loss of lysine during storage of skim milk powder
Uptake of moisture
Threonine
Leucine
Valine
Isoleucine
Phenylalanine
Lysine
Methionine
Histidine
Arginine
Tryptophan
Am
ino
acid
s (
%)
Cystine
Storage (d)
(Henry & Kon, 1948)
Changes in content of essential amino
acids during storage
0
1
2
3
4
5
6
0 0.1 0.2 0.3 0.4 0.5 0.6
Water activity (aw)
Re
ac
tiv
e l
ys
ine
(g
/16
gN
)
0
5
10
15
20
25
30
35
40
Ly
sin
e b
loc
ka
ge
(%
)
Reactive Lys
Blocked Lys
0 %
0 %
0 – 2 %
0 – 2 %
5 – 10 %
5 – 10 %
20 – 50 %
Freeze-drying
Pasteurization
UHT sterilization
Spray-drying
Spray-dried formula
HTST sterilization
Roller-drying
Blocked lysineHeat process
(Finot & Hurrell, 1983)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 42
-60
-40
-20
0
20
40
60
80
100
0 10 20 30 40 50 60 70 80 90 100
Total solids [%]
Te
mp
era
ture
[°C
]
Milkpowder
Fresh milk
concentration
pasteurisation
drying
atomisation
homogenisation
after-drying
after-cooling
Manufacturing of milk powder
Tf
Ts
Solution (emulsion)
Lactose crystals and solution
Ice and solution
Glassy
state
Tg
(Vuataz, 2002)
43
ShelfShelfShelfShelf----life Issues: Browning of Milk Powderlife Issues: Browning of Milk Powderlife Issues: Browning of Milk Powderlife Issues: Browning of Milk Powder
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 44
Shelf-life issues:Browning of milk powder
Issue:
Browning of milk powder was extensively detected under hot climatic conditions
Spontaneous nucleation and crystal formation is possible above the Tg
in a certain range which depends on (T – Tg)
glassyVisco-
elasticTg
Heat orWater addition
Glass transition(reversible)
crystalline
Crystallisation(irreversible)
Mechanism: Recrystallisation of an amorphous powder
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 45
-60
-40
-20
0
20
40
60
80
100
0 10 20 30 40 50 60 70 80 90 100
Total solids [%]
Te
mp
era
ture
[°C
]
Solution
(emulsion)
Ice and solution
Glassy
state
Ts
Tf
Tg
10 min.
1 h.
1 d.
Rubbery stateLactose crystals
and solution
Risk of lactose crystallisation during storage (water uptake)
(Vuataz, 2002)
visco-elastic region
T > Tg : spontaneous
nucleation (β-from)
glassy solid region
T < Tg : no risk
of crystallisation
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 46
Risk of heat
shocks in hot
countries
1 hour WM
20
30
40
50
60
70
80
90 91 92 93 94 95 96 97 98 99 100
Total Solids [%]
Te
mp
era
ture
[°C
]
10 min. 1 day Tg5 min.
1 w
eek 1
mon
th
Risk of lactose crystallisation during storage (heat shock)
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 47
Means of control: Adjust water content and/or limit heat shock
The temperature increases up to 65°C
for a short time (less than one day), due
to transport conditions or sun exposure
during unloading of containers.
Temperature 65°C
30°C
12 h
Strategy:- Adapt the norm of water content to the risk of heat shock (T and duration)
- Better control the final water content of the processed powder
state of lactose
amorphous
crystallineAfter a certain delay (some hours), the
lactose crystallization is initiated and
rapidly achieved (in the beta anhydrous
or the alpha monohydrate form).
water activity
0.20
0.55
The water previously adsorbed on the
amorphous lactose is released, inducing
a large water activity increase (closed
can situation).
Time
browning
white
brownThe resulting high Aw is responsible for
the high rate of Maillard reaction, even
if the temperature is reduced to the
previous value.
48
Process ContaminantsProcess ContaminantsProcess ContaminantsProcess Contaminants
Mitigation Concepts for AcrylamideMitigation Concepts for AcrylamideMitigation Concepts for AcrylamideMitigation Concepts for Acrylamide
2007-09-04 Nestle PTC Orbe / I. Blank / 9th Maillard Munich 49
Agronomic
- Sugars
- Asparagine
- Sugars
- Asparagine
Agronomic Recipe
recipe…….……..
- NH4HCO3
- pH
- Minor ingredients
- Dilution
- Rework
recipe…….……..
recipe…….……..
recipe…….……..
- NH4HCO3
- pH
- Minor ingredients
- Dilution
- Rework
Recipe Process
Fermentation
Thermal input
Pre-treatment
Fermentation
Thermal input-
-
-
-
- Pre-treatment
Final Preparation
- Color endpoint
- Texture/flavour
- Product
storage/shelf life/consumer prep.
- Color endpoint
- Texture/flavour
- Product
storage/shelf life/consumer prep.
Final Preparation
� Guidance to assist in reducing AA levels in food
� Not meant as a formal prescriptive manual
� « Live » document
Means of control: Options to achieve acrylamide mitigation
(http://www.ciaa.be/documents/brochures/CIAA_Acrylamide_Toolbox_Oct2006.pdf)
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Means of control: Potato crisps
Tools to try� Variety selection
� Storage conditions > 6°C
� Reconditioning
� Process management - color
� Formed crisp - partial potato replacement
� Blanching
� Vacuum frying
Future opportunities
� New varieties (sugar, storage qualities)
� Agricultural practices
� Potato varieties with lower Asn
� Asn-ase treatment: formed crisps
� Effect of Ca2+ addition –fabricated crisps
%
0 20 40 60 80 100
Storage Temp.
Frying Temp/Time
Colour Control
Variety Selection
Colour Sort
Recipe Change *
“Tools” used in acrylamide reduction for Potato
Crisps
AA reduction (%)
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Means of control: Bread, bakery wares and breakfast cereals
Tools to try
� Ammonium bicarbonate replacement
� Fructose replacement
� Color / moisture specification change
� Oven condition optimization
� Substitution with < Asn raw materials
Future opportunities� Low Asn raw materials
� Agricultural practices
� Asparaginase
� Fermentation (e.g. yeast)
� Oven profile optimization
� Innovative processing
� Amino acid addition (e.g. glycine)
0
20
40
60
80
0 5 10 15 20
Time (min)
Asn
(m
g/1
00g
)
15°C / 50 ppm
30°C / 50 ppm
30°C / 10 ppm
Asn < 4.1 mg/100g after 5 min, using 10 mg/kg enzyme
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Challenges ahead
� Toolbox concept shows different measures / combinations to achieve
moderate reductions
� In many food categories no reductions achieved so far (exhausting all
currently available options)
� Need to address urgently possible measures at agronomical level
No common solution !
Any mitigation measures must consider:
� Total product quality: The consumer is the judge
Quality is competitive
� Risk/benefit considerations:
� Understand the impact of mitigation steps on safety, nutrient profile
and organoleptic properties
� Position relevance of the suspected side effects of mitigation measures
� Quantify their potential impact
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Outlook: To consider in future research on the “Maillard reaction”
Health & protection:• Evaluate and substantiate effects• Identify target molecules• Discover synergistic and
suppressive effects• Elucidate mechanisms of action• Extend from in-vitro to in-vivo
Food & pleasure:• Apply reaction kinetics / modelling• Elucidate reaction mechanisms• Establish mass balance (major /
minor fluxes)• Focus on low moisture MR• Develop concepts for mitigation• Extend from model studies to food
Nutritional effects
Pleasure & ConvenienceGeneral:• Break down complexity• Favour interdisciplinary science• Combine targeted and holistic
approach• Identify key (bio)active molecules
& transient intermediates