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Polymer’s functionality
SRC
Arnaud DUBAT
Better understand rheological analyses!
• Example : Alveograph
Gluten
Pentosans
StarchNativeDamaged
Moisture
Protein
Ash
Acid viscosity
P L
W
Alveograph
Kw
eon
, Mik
lus,
Sla
de,
& L
evin
e (2
00
3)
P L W Cookie quality
Flour batch A 36 102 108
Flour batch B 38 97 103
« final result is, at the minimum,
the sum of efforts of the
individual contributors »
Imagine a 3 runners relayTotal Time Analysis
Team Total Time
Winner 32 sec
Second 33 sec
Third 34 sec
Fourth 35 sec
TOTAL TIME is an indication of the TEAM PERFORMANCE It tells you HOW the team is performing but not WHY
Imagine a 3 runners relayIndividual Times Analysis
Team Total Time
1st Runner
2nd
Runner3rd Runner
Winner 32 sec 11 sec 11 sec 10 sec
Second 33 sec 11 sec 11 sec 11 sec
Third 34 sec 12 sec 12 sec 10 sec
Fourth 35 sec 9 sec 9 sec 17 sec
INDIVIDUAL RUNNER PERFOMANCE explains TEAM PERFORMANCE
You can only
IMPROVE the
TEAM PERFORMANCE
by ACTING on the
INDIVIDUAL PERFORMANCE
RHEOLOGICAL AND FINISHED PRODUCT LABORATORY TESTING
METHODS TELL YOU
HOWFLOUR WILL FUNCTION
SRC TELLS YOU
WHY
Investigating flour qualityWhat do we have so far?
Quantitative data
• Proteins, ash, fat…
Qualitative data
• Water absorption, tenacity, extensibility…
5 key Drivers for understandingPolymer functionality:
1. « Quantity » does not mean « quality »One might require a minimum « quantity » but this will never guarantee « quality » (think about bug infested wheat!)
2. « Quality » is defined by « Performance »Performance means : does the flour give a ‘good’ dough and the dough a ‘good’ final product. The ‘good » being different for every one.
3. Flour performance depends mainly on flour 3 main polymersGluten (Glutenins), starch (damaged), fibers (pentosans)
4. Rheological tools measure the combined effect of the 3 polymersWe speak about polymer « functionality ».
5. Measuring individual polymer functionality helps better understand dough performance.
It is like going from 2D image to 3D image.
Reminder on the wheat flour
3 main polymers : Protein
Starch (Damaged)
Pentosans
The wheat Kernel
• Components
• Bran (13-20%)– Fibers, ash
• Endosperm (75-85%)– Flour : starch, proteins, water
• Germ (2-4%)– Lipids, vitamins, enzymes…
Industrial interest of proteins
• 2 main proteins form the gluten:– Glutenins (tenacity)
– Gliadines (extensibility)
• These specific properties (tenacity & extensibility) of wheat gluten explain why wheat is a very atypical cereal and why wheat can be used to make bread …
Protein content vs bread volume
Proteins % Proteins %
French bread English bread
Volume Volume
To simplify protein effects
Glutenins(tenacity)
Gliadins(extensibility)
Gluten quality(gas retention)
Starch…in a nutschell
• Starch is a complex sugar…
• Starch is a chain of glucose molecule.
• Starch is an energy stock.
• Glucose is immediately available. It’s a ‘’fast’’ sugar
• Starch is hydrolyzed step by step. It’s a ‘’slow’’ sugar
Industrial interest of starches
• Starch forms fragile granules. During milling process, starch granules can be damaged and their properties change
• In the presence of water and heating, starch granules swell and form a viscous gel: it correspond to starch gelatinization
• During cooling, the starch molecules organisation change and the starch become harder. It correspond to starch retrogradation
Damaged starch rules!
• When a starch granule is damaged:
– Its water absorption capacity is multiplied by 10
– Starch molecules are more accessible to enzyme hydrolysis and lot of sugar are released. These sugar will be used by yeast
Pentosans
Hemicellulose
Pentosans
Xylan
ArabinoxylanFerulic acid
EsterCumaric Acid
Ester
Arabinan
Hexosan
BetaGlucan Galactan Mannanan
Pentosans effects on the dough
• Pentosans come to a great extentfrom the outer part of the wheatkernel (Bran)
• They represent between 2 to 3% of the flour.
• We divide Pentosan in two groups according to their solubility in water– Soluble (1/3)– Non soluble (2/3)
• Pentosans can bind up more than10 time their weight of water.
• Pentosans can link to Protein and reinforce the gluten network (via Ferulic acid)
• Effect on water absobtion diverge on the type of pentosan :– Positive with soluble pentosan– Negative with insoluble pentosans
(important and hererogenouintake, detrimental to Gluten formation).
Impact on dough rheological properties and final product quality
Proteins Damaged Starch Pentosans
Water intake ++ +++ ++++
Stiffness ++ ++ ++
Extensibility -/+ - --
Elasticity ++ --
Gas retention ++ - Soluble high loaf volumeInsoluble low loaf volume
Gas production No effect +++
Volume Depends ++ (if good retention) +/-
Colour - ++++
Stickiness/viscosity -- ++ (Excess) Soluble and insoluble fibers both increase dough consistency
Breakage (biscuit) ++ ++
Crispiness (final product) -- - -
Shelf Life (Bread) + + (Insoluble)
3 steps for determining QUALITY
Hot to measure polymer
Functionality?
Measuring polymer functionality?a sponge trick!
• Each flour polymer is able to specifically absorb a particular solvent:
• Sodium Carbonate for Damaged starch
• Sucrose for Pentosans
• Lactic Acid for Glutenins
• The principle will be to make flour swell into these solvents.
• Like a sponge, the polymer will absorb its solvent.
• Then we will force the solvent out of the polymer.
• If the polymer has high functionality it will retains a bigger quantity of solvent
• Like when you try to remove water for a sponge, there is always some water « linked » with the sponge.
OK, now: think like a sponge!
• Practical aspect:
1. The table 1 shows 2 flours having the same absorption BUT showing big differences in terms of polymer composition.
2. The Table 2 shows 2 flours having the same quantitative composition but different resulting absorption.
– This means that an information linking the « composition » and the « observed result » is missing : this missing information is the polymer functionality.
Table 1 Flour A Flour B
Proteins 9.31 12.77
Starch Dam. 26 23.5
Ash 0.67 0.85
Water Absorption
60.7 60.8
Table 2 Flour A Flour B
Proteins 11.41 11.44
Starch Dam. 25.3 25.6
Ash 0.65 0.62
Water Absorption
58.4 60.0
Continue to think like a sponge!
• If you can know the functionality of each polymer you are then in position to understand its individual contribution to the synergetic qualitative observation.
• You can then adopt the same thinking to analyze each polymer contribution to dough tenacity, extensibility, stickiness…
• Sometimes you want your result being related with one specific polymer and not the other ones• For example in cookie making you want to have the
lowest water absorption and you want to avoid absorption linked with Pentosans or damaged starch. Only absorption by Glutenins is « good absorption ».
• Now if you now which polymer is « good » or « bad » for your product you can select flour not only on quantity but also on functionality
Total Water
Absorption
Absorption by
pentosan
Absorption by glutenin
Absorption by damage
starch
Examples of specifications
020406080
100120140160
Water
Sucrose
Lactic acid
Sodium carbonate
Maraquetta
Chili 1
Chili 2
Chili 3
020406080
100120140160
Water
Sucrose
Lactic acid
Sodium carbonate
Pan Bread
UK 1
UK 2
USA 1
USA 2
USA 3
020406080
100120140160
Water
Sucrose
Lactic acid
Sodiumcarbonate
Steam bread
China 1
China 2
Korea 1
Korea 2
020406080
100120140160
Water
Sucrose
Lactic acid
Sodium carbonate
Cookie
USA
SRC map
0
20
40
60
80
100
120
140
Water
Sucrose
Lactic acid
Sodium carbonate
All samples
Artisan breadBaguette T55Baguette T65BaklavaBiscuitCake/cookiesMaraquettaNoodlesPan BreadPizza
Conclusion
• SRC test measures flour quality and functionality
• SRC is highly beneficial and complementary to quantitative and rheological analyses
• Make sure all players are running to their maximum capacity!
Thank you for your attention